Ansoft Maxwell v12 2D User Guide-Machine Design Reference Guide

Ansoft Electrical Machine Design Reference Revision: June, 2008

2 Ansoft Maxwell Field Simulator V12—Electric Machine Design Reference

Project Manager Window

3D Modeler Window

History Tree Window

Properties Window

Message Window

Progress Window



Toolbar: 2D Objects Rotate around current axis

Toolbar: 3D Objects Zoom In/Out

Fit selected

Pan

Rotate around model center

Rotate around screen center

Dynamic zoom

Fit all



• General Shortcuts

3D Modeller Shortcuts

• • • • • • • • • • • • • •

• • • • • • • • • • • • • •

•

Help: F1 Context help: Shift + F1 Close program: CTRL + F4 Copy: CTRL + C New project: CTRL + N Open: CTRL + O Save: CTRL + S Print: CTRL + P Paste: CTRL + V Cut: CTRL + X Redo: CTRL + Y Undo: CTRL + Z Cascade windows: CTRL + 0 Tile windows horizontally: CTRL + 1 Tile windows vertically: CTRL +2

• •

Select face/object behind current selection: B Face select mode: F Object select mode: O Select all visible objects: CTRL + A

Set model projection to standard isometric projections: Alt + Double Click Left Mouse Button at points on screen

•

ALT + Right Mouse Button + Double Click Left Mouse Button at points on screen: give the nine opposite projections

Deselect all objects: CTRL + SHIFT + A Fit view: CTRL + D Zoom in, screen center: CTRL + E Zoom out, screen center: CTRL + F Shifts the local coordinate system temporarily: CTRL + Enter Drag: SHIFT + Left Mouse Button

Predefined View Angles

Rotate model: Alt + Left Mouse Button Zoom in / out: Alt + SHIFT + Left Mouse Button Switch to point entry mode (i.e. draw objects by mouse): F3 Switch to dialogue entry mode (i.e. draw object solely by entry in command and attributes box.): F4 Render model wire frame: F6 Render model smooth shaded: F7


Full Integration of RMxprt and Maxwell

RMxprt and Maxwell are now fully integrated. All RMxprt data is exported to Maxwell 2D in version 12. This includes geometry, materials, excitations, boundaries, motion setup, solution setups, mesh operations, result plots, etc. For Maxwell 3D, this includes geometry and materials 8 Ansoft Maxwell Field Simulator V12—Electric Machine Design Reference

Full Integration of RMxprt and Maxwell

Motion setup Geometry Boundaries Excitations Mesh operations

Materials

Solve setup Results plots

Ready to solve! In menu bar, click on Maxwell 2D > Analyze All 9 Ansoft Maxwell Field Simulator V12—Electric Machine Design Reference

Integration to 3D: Geometry with Skew and End-turn, Materials

Geometry

Materials













Symmetry: Even (Flux Normal)

Symmetry: Odd (Flux Tangential)


(Flux can exit and re-enter the bound-

(Flux can not escape the bound23

Ansoft Maxwell Field Simulator V12—Electric Machine Design Reference





Surface Deviation is the maximum spacing, in drawing units, that the triangle surfaces may be from the true-curved geometry’s surface Normal Deviation is the maximum angular difference, in degrees, that a triangle face’s normal can have from the surface normal for the true geometry which it is meant to represent Aspect Ratio refers to the maximum allowed aspect ratio of all faces





1. To assign Torque/Force calculation in a Magnetostatic simulation: select the object (s) > right mouse click > Assign Parameters 2. A Band object is recommended in Magnetostatic simulations, but not required. The band is a dummy air/vacuum object between moving and stationary parts. 3. A Band object is required for Transient simulations with motion. 4. In a Transient simulation, moving torque is assigned by the solver automatically. 5. The moving torque calculated in a Transient simulation is the torque on all objects INSIDE the band (not including the band). For a Magnetostatic simulation, a user must manually assign the torque parameter on all objects inside the band. 6. A Force calculation can also be assigned in the Transient solver in Maxwell 2D V12. There is no limit on how many forces can be calculated. This is not the case for V11. 32 Ansoft Maxwell Field Simulator V12—Electric Machine Design Reference





View > Set Solution Context ...

Double click


Parametrics: Define one or more variable sweep definitions, each specifying a series of variable values within a range. Easily view and compare the results using plot or table to determine how each design variation affects the performance of the design. Optimization: Identify the cost function and the optimization goal. Optimetrics automatically changes the design parameter(s) to meet the goal. The cost function can be based on any solution quantity that can be computed, such as field values, R,L,C force, torque, volume or weight. Sensitivity: Determine the sensitivity of the design to small changes in variables in the vicinity of a design point. Outputs include: Regression value at the current variable value, first derivative of the regression, second derivative of the regression. Tuning: Variable values are changed interactively and the performance of the design is monitored. Useful after performing an optimization in Optimetrics to fine tune the optimal variable value and see how the design results are affected. Statistical: Shows the distribution (Histogram) of a design output like force, torque or loss caused by a statistical variation (Monte Carlo) of input variables. 38 Ansoft Maxwell Field Simulator V12—Electric Machine Design Reference

Geometry Excitation Materials Frequency Speed Torque/Force Inductance 39 Ansoft Maxwell Field Simulator V12—Electric Machine Design Reference




Parametric variations: 1296 Solve time, one processor: 13 hr, 15 min Solve time, distributed, 8 CPUs: 2 hr, 30 min

Speed improvement: 5.3X 43 Ansoft Maxwell Field Simulator V12—Electric Machine Design Reference

Permanent Magnet Synchronous Machine XY Plot 2

Ansoft Corporation

PMSM_CT

1.20

Curve Inf o Bradial Setup1 : Transient Time='0ns'

1.00

0.80

Bradial

0.60

0.40

0.20

0.00

-0.20

0.00

0.20

0.40

0.60

0.80

1.00

Norm alizedDis tance

Cogging Torque

Ansoft Corporation

PMSM_CT_Verify

XY Plot 2

Ansoft Corporation

Core Loss

Ansoft Corporation

3.00

PMSM_OC_EMF

1.20

Curve Info

PMSM_OC_EMF

Optimized Design Setup1 : Transient

150.00

2.2271

Moving1.Torque Imported Nominal Design

2.00

Curve Info CoreLoss Setup1 : Transient

1.00

Y1 [V]

50.00

0.00

Curve Info

1.00 0.5877

0.80 0.4354

CoreLoss [kW]

Y1 [NewtonMeter]

100.00

0.1402

0.00

-1.00

0.60

0.40

InducedVoltage(PhaseA) Setup1 : Transient InducedVoltage(PhaseB) Setup1 : Transient

-50.00

-2.00

InducedVoltage(PhaseC) Setup1 : Transient

0.20 -100.00

-3.00 0.00

1.00

MX1: 0.6379

-150.00 0.00

2.00

4.00

Time [ms ]

6.00

8.00

10.00

Ansoft Maxwell Field Simulator V12 – Training Manual

2.00

3.00

4.00 Time [s]

5.00

6.00

MX2: 5.4031

7.00

8.00

0.00 0.00

2.00

4.00

Time [ms]

6.00

8.00

10.00

P1-1

Permanent Magnet Synchronous Machine: Contents

RMxprt

Maxwell: Open Circuit Back EMF Basic Theory Review Example Add Unique Winding Arrangement Setup Parametric Problem Export Design to Maxwell 2D

Maxwell: Cogging Torque Review Maxwell Setup Create Variables Apply Mesh Operations Solve Nominal Problem Setup Optimization Problem Review Pre-Solved Optimization Results

Define Material Core Loss Characteristics Set Lamination and Stack Factor Consider Power Loss in Magnets Solve Problem and Review Results

Maxwell: Rated Condition – Functional Voltage Source Modify Rotor Geometry using UDP’s Winding Setup Definitions and Variable Definition Choosing Optimal Time Step Solve Problem and Review Results

Drive Design Create a Machine Model Use the Model in Circuit Simulation

Notes: 1. RMxprt/Maxwell V12 or higher is required 2. Basic knowledge of electric machine is required 3. Basic understanding of Finite Element is required Ansoft Maxwell Field Simulator V12 – Training Manual

P1-2

Electric Machine Design Suite A Complete Solution for Modern Electric Machines and Drives Design

Design Requirements 9 9 9 9 9 9 9 9 9 9

Fast Analytical Solution: Narrow the Design Space

Size/Weight Efficiency Torque Speed Cogging/Ripple Inverter Matching Thermal Stress Manufacturability Cost

Transient Analysis using FEA Parametric Analysis Simultaneous Equations:

Magnetostatic/Eddy Current Analysis using FEA

IGBT

D2

IGBT

if − C

duc =0 dt

mα + λω = Tem + Texternal

Motion Equation

ω FM_ROT

IGBT IA A_PHASE_N1

IB

ROT2

A

+ VBC V

+

T

ROT1

A

B_PHASE_N1

IC A

EMF

di dA Circuit Equation: d f dΩ + R if + L f + uc = us S f a ∫∫ dt dt

D3 ECELink

175

∂A − σ∇V + ∇ × Hc + σv × ∇ × A ∂t

Nfl

Parametric Analysis Optimization

Parametric Analysis Optimization

EMF

Field Equation: ∇ ×υ∇ × A = J s − σ

C_PHASE_N1

175

IGBT

IGBT ECE

A

AM_IGB ICA:

PP:=

EQU

ON:=

theta_elect := PP * ECELink theta := MOD(theta_elect

OFF:= THRESH:=4 HYST:=

Torqu

Phase Curre 1.00

IA IB IC

500.0

Phase Voltag To

400.0

300.0

V_A

200.0

Von Mises stress

200.0 0

0 -500.0

0

0

10.00m

-200.0

-100.0 0

-1.00

17.27mt

10.00

-300.0 0

17.27 t

10.00

17.27 t

Drive System using System Level IGBT’s and Analytical Motor Model

Thermal and Stress Analysis

EMSSLink1 EMSSLink1 175

R5

MASS_ROTB1

R1

R3

E5

IA

RA

V

theta>90 AND theta<150

ctrl_6:=ON

C_PHASE_N2

+

R4

R6


ctrl_2:=ON

ctrl_1:=ON

ctrl_3:=ON


A

ICA:

AM_IGBT


ctrl_1:=ON ctrl_2:=ON



ctrl_1:=OFF ctrl_2:=OFF

ctrl_5:=ON





ctrl_5:=ON

Drive System Integration with Manufacturer’s IGBTs Ansoft Maxwell Field Simulator V12 – Training Manual



ctrl_5:=OFF ctrl_6:=OFF ctrl_4:=ON

theta>330 OR theta<30

V




VGE4

E4

E6


ctrl_6:=ON

C_PHASE_N1

175

R2


ctrl_5:=ON

B_PHASE_N2

RC 0.023

ICA:

AM_IGBT

ctrl_6:=ON


B_PHASE_N1

IC A

EMF1

A_PHASE_N2

0.023




V

C_PHASE_N1

V

E4

E2

ctrl_1:=ON

ROTB2

RB A

+ VBC

VGE4

A

ROTB1

0.023 A_PHASE_N1

IB

B_PHASE_N2

RC 0.023

C_PHASE_N2

R4

E6

RA A

B_PHASE_N1

IC A

R6

E2

IA

E1

E3

E5

A_PHASE_N2

0.023

175 R2

R3

R5

ROTB2

RB A

+

EMF1

MASS_ROTB1

R1

175

A_PHASE_N1

IB

VBC

EMF2

ROTB1

0.023

A

E1

E3

+

EMF2

Equivalent Circuit Model : High Fidelity Physics Based Model


ctrl_6:=ON

ctrl_4:=ON theta>330 OR theta<30

ctrl_5:=ON



Complete Transient FEA -Transient System Co-simulation P1-3

RMxprt: Background ASSM: Adjustable-Speed Synchronous Machine Rotor speed is controlled by adjusting the frequency of the input voltage Unlike brushless PMDC motors, ASSM does not utilize the position sensors. Rotor can be either inner or outer type Can operate as a generator or as a motor Motor Mode: Sinusoidal AC source DC source via a DC to AC inverter

Generator Mode: Supplies an AC source for electric loads


P1-4

ASSM: Background Input voltage U is the reference phasor, let the angle I lags U be φ, the power factor angle

I = I∠ − ϕ Let the angle I lags E0 be ψ. The d- and the q-axis currents can be obtained respectively as follows:

Id   sinψ  I =   = I  I cos ψ    q

ψ = tan

−1

Id Iq


P1-5

ASSM: Background

OM can be used to determine the direction of E0 OM = U − I ( R1 + jX 1 + jX aq ) Let the angle E0 lags U be θ, which is called the torque angle for the motor, then the angle ψ is ψ = ϕ −θ For a given torque angle θ : Xd − R  1

R1   I d  U cosθ − E0  =  X q   I q  − U sin θ 

Solving for Id and Iq yields: Id  1 = I  2  q  R1 + X d X q

 X q (U cosθ − E0 ) + R1U sin θ   R (U cosθ − E ) − X U sin θ  0 d  1 


P1-6

ASSM: Background The power factor angle φ is

ϕ = ψ +θ

The Input electric power is

P1 = 3UI cos ϕ

The Output mechanical power is

P2 = P1 − ( Pfw + PCua + PFe )

Pfw : Frictional and Wind Loss PCua: Armature Copper Loss PFe : Iron-core Loss

Torque:

T2 =

P2

ω

Efficiency: η=

P2 × 100% P1


P1-7

RMxprt: Base Project Open the RMxprt project located on your desktop by double clicking on

PM_SyncMotor.mxwl

Save the project under a new name: File > Save As > c:\Training\PM_SyncMotor.mxwl

Select Setup1 under Analysis and click the Right Mouse Button (RMB) and Choose Analyze


P1-8

RMxprt: Results Select Setup1, click the RMB and choose Performance

Choose a Solution Set


P1-9

RMxprt: Results Select Setup1, click the RMB and choose Performance

Choose a Performance Curve


P1-10

RMxprt: Add New Winding Arrangement Double click on Stator > Winding Click on Whole-Coiled Select Editor

1 2

3


P1-11

RMxprt: Add New Winding Arrangement In the Winding Editor Panel, click the RMB and select Edit Layout

Deselect Constant Pitch Change the Layout as shown


P1-12

RMxprt: Add New Winding Arrangement View the new winding arrangement by placing the mouse over one of the A phase coils in the drawing window and click the RMB selecting

Connect One Phase Coils.


P1-13

RMxprt: Performance Solve the problem by selecting Setup1 under Analysis and click the Right Mouse Button (RMB) and Choose Analyze Select Setup1, click the RMB and choose Performance


P1-14

RMxprt: Add Variables Click on Winding and in the Properties window, next to Conductors Per Slot type in CPS

1 2 Click on Stator and in the Properties window, next to Length type in

Depth

1 2


P1-15

RMxprt: Add Variables Click on Rotor and in the Properties window, next to Length type in

Depth

Select menu item RMxprt > Optimetrics Analysis > Add Parametrics


P1-16

RMxprt: Parametric Setup Click on Add and setup the two variables as follows:

4

2

1

3

Click on the Calculations Tab > Setup Calculations and add the following Current > RMSLineCurrentParameter Power > OutputPowerParameter Misc. > EfficiencyParameter


P1-17

RMxprt: Parametric Solution Select ParametricSetup1 under Optimetrics, click the RMB and Analyze

Select ParametricsSetup1, click RMB and select View Analysis Results Select Table and then click on Efficiency Parameter

Efficiency increased from 89% to over 98% while maintaining output power Ansoft Maxwell Field Simulator V12 – Training Manual

P1-18

RMxprt: Create Maxwell Design Select Setup1, click the RMB and select Create Maxwell Design

2

4

deselect

1

Choose 3 Ansoft Maxwell Field Simulator V12 – Training Manual

P1-19

Maxwell 2D: Base Design

Motion Boundaries Winding

Material Assignment

Mesh

Soln. Setup Results


P1-20

Maxwell 2D: Cogging Torque, Excitation Select the PhaseA winding, click the RMB and select Properties Change the Type to Current with a value of zero

Repeat this for PhaseB and PhaseC


P1-21

Maxwell 2D: Cogging Torque, Mesh Ops Select Length_Magnet under Mesh Operations, click the RMB and select Properties

Decrease the size of the element by half. Just type in 3.75/2


P1-22

Maxwell 2D: Cogging Torque, Mesh Ops. Select Length_Main under Mesh Operations, RMB and select Properties

Decrease the size of the element by 4. Just type in 10.96/4


P1-23

Maxwell 2D: Cogging Torque, Mesh Ops. Select SurfApprox_Mag under Mesh Operations, RMB and select

Properties

Decrease the length of the “Maximum Surface Deviation” to 190 nm. This yields an angular segmentation of Θ = 0.25 deg.

D = r (1 − cos(Θ / 2)) r is the inside radius of the stator which is 81mm


P1-24

Maxwell 2D: Cogging Torque, Mesh Ops. Select SurfApprox_Main under Mesh Operations, RMB and select

Properties

Decrease the length of the “Maximum Surface Deviation” to 190 nm


P1-25

Maxwell 2D: Cogging Torque, Mesh Ops.

Three possible operations: D

D = Maximum Surface Deviation D = r (1 − cos(Θ / 2))

r

Θ = Maximum Surface Normal Deviation

Θ

ri

ro Ansoft Maxwell Field Simulator V12 – Training Manual

2 * ri 2 = ShapeFactor (2 D ) ro 1 3 * ri = SF (3D) AR=2 ro 1 Aspect Ratio of Cells, AspectRatio = SF not of triangles P1-26

Maxwell 2D: Cogging Torque, Mesh Ops. Select Band in the modeler tree, RMB and select Properties

Decrease the SegAngle value to 0.25 degrees

NOTE!: This small value for angular segmentation, 0.25deg, is needed only for very sensitive calculations such as Cogging Torque Ansoft Maxwell Field Simulator V12 – Training Manual

P1-27

Maxwell 2D: Cogging Torque, Mechanical Setup Select Motion Setup1 under Model, RMB to select Properties Select Mechanical Tab and change speed to 1 deg/sec

Select Setup1 under Analysis and RMB to select Properties


P1-28

Maxwell 2D: Cogging Torque, Solution Setup Change to Save Fields tab

1

3

2


P1-29

Maxwell 2D: Cogging torque, Results Solve the cogging torque problem by selecting Setup1 under Analysis, RMB and select Analyze: Once the problem is solved double click on

Results > Torque Torque

Ansoft Corporation

Maxwell2DDesign1

3.00

Click the RMB in the plot and select Export Data. Save the plot on the desktop.

Curve Info Moving1.Torque Setup1 : Transient

2.00

Moving1.Torque [NewtonMeter]

1.00

0.00

-1.00

-2.00

-3.00 0.00

5.00

Time [s]


10.00

15.00

Since the speed is held constant at 1.0 deg/sec, the X-Axis represents both time and position, i.e. 10 sec = 10 deg P1-30

Maxwell 2D: Cogging torque, Results Select menu item View > Set Solution Context, and choose zero seconds.

In the drawing window hit CTRL+A to select all objects, RMB to select Fields > A >

Flux_Lines


P1-31

Maxwell 2D: Cogging torque, Results

Double Click on Legend to change plot properties


P1-32

Maxwell 2D: Cogging torque, Results Select Flux_Lines1 under A under Field Overlays, RMB to select

Animate


P1-33

Maxwell 2D: Cogging torque, Rename Design Rename Maxwell2DDesign1 by selecting its name in the project tree, RMB and select Rename. Change the name to PMSM_CT for Permanent Magnet Synchronous Motor Cogging Torque.


P1-34

Maxwell 2D: Cogging torque, Variables Select CreateUserDefinedPart under Mag_0 under NdFe30_N and choose Properties

3

1

2 In the Value field type in the name PoleEmbrace


P1-35

Maxwell 2D: Cogging Torque, Optimization Variables Change the field for the ThickMag to MagnetThickness and accept the default value of 7.5mm

2

1


P1-36

Maxwell 2D: Cogging Torque, Optimization Variables Change the field for the Offset to PoleOffset and accept the default value of 0mm.

2

1 Ansoft Maxwell Field Simulator V12 – Training Manual

P1-37

Maxwell 2D: Cogging Torque, Optimization Variables Select CreateUserDefinedPart under InnerRegion under Vacuum and choose Properties

1

2 In the Value field type in the names: PoleEmbrace MagnetThickness PoleOffset


P1-38

Maxwell 2D: Cogging Torque, Optimization Variables Select CreateUserDefinedPart under Rotor under M19_26G_SF0.950 and choose Properties

1 2 In the Value field type in the names: PoleEmbrace MagnetThickness PoleOffset


P1-39

Maxwell 2D: Cogging Torque, Optimization Variables Select menu item Maxwell 2D > Design Properties and change the value of the variables just defined:

Select the Optimization radio button and Include each variable:


P1-40

Maxwell 2D: Cogging Torque, Optimization Variables Modify the variable to see the effect on the geometry

For this exercise, the range for each is: 6.5 mm < MagnetThickness < 9.5 mm 0.6 < PoleEmbrace < 0.9 0 < PoleOffset < 30 mm

PE

MT

Pole Offset Ansoft Maxwell Field Simulator V12 – Training Manual

P1-41

Maxwell 2D: Cogging Torque Optimization, Air Gap Arc Create an arc in the air gap to be used for post processing purposes, by selecting menu item Draw > Arc > Center Point

Using the mouse select the origin, any point in the air gap along the X axis and any point in the air gap at the 45 degree angle. Any value used if valid, it will be modified in the next step. Double 3 click to end

1 2 Ansoft Maxwell Field Simulator V12 – Training Manual

P1-42

Maxwell 2D: Cogging Torque Optimization, Air Gap Arc Select CreateAngularArc under CreatePolyline under Polyline1 under Lines, RMB and select Properties

Change the value for the starting point to 80.8, 0, 0. This will place the arc between the band object and the stator ID

Select Polyline1. In the Properties window change its name to AG_Arc Ansoft Maxwell Field Simulator V12 – Training Manual

P1-43

Maxwell 2D: Cogging Torque Optimization, Variables Select menu item Maxwell 2D > Field > Calculator Perform the following commands to calculate the radial component of the flux density in the air gap Quantity > B Scal? > Scalar X Function > PHI Trig > cos Multiply * Quantity > B Scal? > Scalar Y Function > PHI Trig > sin Multiply * Add + -- this gives Bx*cos(PHI) + By*sin(PHI) Add … > Name: Bradial -- this adds the express to the stack


P1-44

Maxwell 2D: Cogging Torque Optimization, Variables Continue to calculate the average radial component of the air gap flux density Select Bradial under Named Expressions Copy to Stack Geometry > Line > AG_Arc Integrate Number > Scalar > Value = 1 Geometry > Line > AG_Arc Integrate Divide / -- this give the average radial flux density in the air gap Add … > Name: Brad_Avg -- this adds this expression to the stack


P1-45

Maxwell 2D: Cogging Torque Optimization, Variables Continue to calculate the area of the permanent magnet Number > Scalar > Value = 1 Geometry > Surface > Mag_0 Integrate Number > Scalar > Value = 1e6 -- this converts from m2 to mm2 Multiply * Add … > Mag_Area -- this adds this expression to the stack

Select the Maxwell 2D Design PMSM_CT and in the Properties window change the variables back to their default values

Even though the design variables and thus the geometry has changed, once the design variables are set to their previous values, the solution is automatically reloaded; there is no need to solve the problem again. Ansoft Maxwell Field Simulator V12 – Training Manual

P1-46

Maxwell 2D: Cogging Torque Optimization, Variables Plot the radial flux density in the air gap by selecting Results, RMB to select Create Field Report > Rectangular Plot


P1-47

Maxwell 2D: Cogging Torque Optimization, Brad AG Plot B_rad on the AG_Arc

5 1

4 2 3

6

10 7


8

9

P1-48

Maxwell 2D: Cogging Torque Optimization, Brad AG Plot of B radial in air gap at time zero XY Plot 2

Ansoft Corporation

PMSM_CT

1.20

Curve Inf o Bradial Setup1 : Transient Time='0ns'

1.00

Click the RMB in the plot window and select Export Data. Save the plot on the desktop.

0.80

Bradial

0.60

0.40

0.20

0.00

-0.20

0.00

0.20

0.40

0.60

0.80

1.00

Norm alizedDis tance


P1-49

Optimization: Solution Setup Change the Stop Time of the Simulation from 15 seconds to 3.75 sec. The cogging torque waveform is symmetric after 3.75 deg (equal to 3.75 sec) and to save simulation time we only need to solve up to this point. Select Setup1 under Analysis and RMB to select Properties


P1-50

Maxwell 2D: Cogging Torque Optimization, Variables Select Optimetrics and RMB to select Add > Optimization

Next to Optimizer select Genetic Algorithm


P1-51

Maxwell 2D: Cogging Torque Optimization Setup Click on Setup

Change the values as shown here


P1-52

Maxwell 2D: Cogging Torque Optimization Setup Cogging Torque Peak Nominal Value* = 2.2 N-m Maximum Value** = 5.5 N-m Optimal Goal = 0.2 N-m (subjectively chosen, we want to reduce CT by >10x) Normalize Solution Range: 1 to 10 G1 = 1 + (max(abs(Torque)) – 0.2) * 9 / 5.3 Objective: G1 = 1.0 *Note:

The Peak Nominal Value is when: MagnetThickness = 7.5 mm PoleEmbrace = 0.85 PoleOffset = 0 mm

**Note:

The Maximum Value is determined when these values are a Maximum: MagnetThickness = 9.5 mm PoleEmbrace = 0.90 PoleOffset = 0 mm

The maximum value of cogging torque may lay outside these parameter values, i.e somewhere else in the solution domain. These values are used just to define a range for the objective. Ansoft Maxwell Field Simulator V12 – Training Manual

P1-53

Maxwell 2D: Cogging Torque Optimization Setup Nominal Bavg Value = 0.76 Tesla Range*: 0.50 < Bavg < 0.81 Tesla Optimal Goal = 0.76 Tesla (we want to maintain the Air Gap Flux Density) Normalize Range: 1 to 10 G2 = 1 + (Brad_Avg – 0.5) * 9 / 0.31 Objective: G2 = 8.55

Magnet Area Range*: 220 < Mag_area < 510 mm2 Normalize Range: 1 to 10 G3 = 1 + (Mag_area – 220) * 9 / 290 Objective: G3 = 1.0

*Note:

The Range was calculated by simulation the minimum and maximum values: MagnetThickness … 6.5 mm and 9.5 mm PoleEmbrace … 0.6 and 0.9 PoleOffset .. 0 mm and 30 mm


P1-54

Maxwell 2D: Cogging Torque Optimization Setup In the Calculation Expression field type in the function as shown below

1

3

2

4


P1-55

Maxwell 2D: Cogging Torque Optimization Setup Include Calculation for the average radial component of the flux density in the air gap

1

2

3

4

Type in the rest of the expression and then click on Add Calculation


P1-56

Maxwell 2D: Cogging Torque Optimization Setup Include calculation for Magnet Area

1

2

3

Type in the rest of the expression and then click on Add Calculation


P1-57

Maxwell 2D: Cogging Torque Optimization Setup For the calculation expressions for Brad_Avg and Mag_Area click on Calc. Range and select 0ns for time zero

1


P1-58

Maxwell 2D: Cogging Torque Optimization Setup

Set the Goal and Weigh for each objective

Cost1 = (G1 – 0.2)2 * W1 Cost2 = (G2 – 0.75)2 * W2 Cost3 = (G3 – 230)2 * W3 Cost = Cost1+Cost2+Cost3

where G1 = max(abs(Torque)) where G2 = abs(AirGap_Bavg) where G3 = Mag_area

Note: The Cogging Torque and Air Gap Flux Density have equal weight, which is twice that of the magnet area Ansoft Maxwell Field Simulator V12 – Training Manual

P1-59

Maxwell 2D: Cogging Torque Optimization Setup Click on the Variables tab and change the values accordingly:

This problem takes too long to solve during the class. The full solution can be downloaded from Ansoft’s FTP site: ftp://ftp.ansoft.com/download/ChinaTraining/PM_SyncMotor_Opt.zip

To solve the problem, select OptimizationSetup1 under Optimetrics, RMB and select Analyze


P1-60

Maxwell 2D: Cogging Torque Optimization Results


P1-61

Maxwell 2D: Cogging Torque Optimization Setup Since the field solution was not saved for each variation in the optimization solution, create a second Maxwell 2D design and solve the problem with the optimized design variable values. Select the Maxwell 2D design PMSM_CT, RMB and select Copy

Select the project name PM_SyncMotor, RMB and select Paste

Select the Maxwell 2D design PMSM_CT1, RMB and select Rename, and change the design name to PMSM_CT_Verify


P1-62

Maxwell 2D: Cogging Torque Optimization Verify Select the design PMSM_CT_Verify and in the Properties window change the design variables to the Optimized value

Increase the Stop Time to 7.5 sec and then solve the design:

1

2

3


P1-63

Maxwell 2D: Cogging Torque Optimization Verify Plot the Cogging Torque Cogging Torque

Ansoft Corporation

PMSM_CT_Verify

0.50

Curve Info Optimized Design Setup1 : Transient

0.40

Optimized Design [NewtonMeter]

0.30 0.20 0.10 0.00

-0.10 -0.20 -0.30 -0.40 -0.50 0.00

1.00


2.00

3.00

4.00 Time [s]

5.00

6.00

7.00

8.00 P1-64

Maxwell 2D: Cogging Torque Optimization Verify In the plot window RMB to select Import Data and pick the cogging torque plot that was exported earlier. Cogging Torque

Ansoft Corporation

PMSM_CT_Verify

3.00 Curve Info Optimized Design Setup1 : Transient

2.2271

Moving1.Torque Imported Nominal Design

Y1 [NewtonMeter]

2.00

1.00 0.5877

0.4354

In plot window, RMB and select Marker > Add X Marker Optimized Design

0.1402

0.00

Nominal Design -1.00

-2.00

-3.00 0.00

1.00

2.00

MX1: 0.6379


3.00

4.00 Time [s]

5.00

6.00

7.00

8.00

MX2: 5.4031

P1-65

Maxwell 2D: Cogging Torque Optimization Verify Plot the air gap flux density Air Gap Flux Density

Ansoft Corporation

PMSM_CT_Verify

1.20

Curve Info Bradial Setup1 : Transient Time='0ns'

1.00

Bradial

0.80

0.60

0.40

0.20

0.00

-0.20 0.00

0.20


0.40 0.60 NormalizedDistance

0.80

1.00 P1-66

Maxwell 2D: AG Flux Density In the plot window RMB to select Import Data and pick the Air Gap flux density plot that was exported earlier. Air Gap Flux Density

Ansoft Corporation

PMSM_CT_Verify

1.20

Curve Info Bradial Setup1 : Transient Time='0ns' Bradial Imported Nominal Design

1.00

Bradial

0.80

0.60

0.40

0.20

0.00

-0.20 0.00

0.20


0.40 0.60 NormalizedDistance

0.80

1.00 P1-67

Maxwell 2D: AG Flux Density Determine the average air gap flux density.

1 2 3 The target optimized value is 0.76T


4

P1-68

Maxwell 2D: Magnet Area Determine the magnet area.

1

The area of the magnet for the nominal design was 383 mm2


2

3

P1-69

Maxwell 2D: Open Circuit Back EMF Select the design PMSM_CT_Verify, RMB and select Copy

Select the project PM_SyncMotor, RMB and select Paste

Select the new design PMSM_CT_Verify1, RMB and select Rename. Change the name to PMSM_OC_EMF


P1-70

Maxwell 2D: Open Circuit Back EMF Select MotionSetup1 under Model, RMB to select Properties

Select the Mechanical tab and change the speed to 3600 rpm


P1-71

Maxwell 2D: Open Circuit Back EMF, Core Loss Setup

Calculate the core loss coefficients from multiple core loss curves


P1-72

Maxwell 2D: Open Circuit Back EMF, Core Loss Setup Select the Stator and in the Properties widow click on the material M19_26G_SF0.950 and then select View/Edit Material

1 2 3 Ansoft Maxwell Field Simulator V12 – Training Manual

P1-73

Maxwell 2D: Open Circuit Back EMF, Core Loss Setup Add the core loss curve for 60Hz

3

Choose the file 4 M470-65A-60Hz.tab

1

2


P1-74

Maxwell 2D: Open Circuit Back EMF, Core Loss Setup Add the core loss curve for 100Hz

3

Choose the file 4 M470-65A-100Hz.tab

1

2


P1-75

Maxwell 2D: Open Circuit Back EMF, Core Loss Setup Continue to add the following curves: M470-65A-200Hz.tab M470-65A-600Hz.tab


M470-65A-400Hz.tab M470-65A-700Hz.tab

M470-65A-1kHz.tab

P1-76

Maxwell 2D: Open Circuit Back EMF, Magnet Loss Select Mag_0 and in the Properties next to Materials click on NdFe30_N and then on View/Edit Materials. Change the conductivity to 625000 S/m

Material properties are global quantities, the affect all designs. Thus when modifying materials that are common to various designs, the solutions to the designs become invalid.


P1-77

Maxwell 2D: Open Circuit Back EMF, Magnet Loss Select Mag_0, RMB to select Assign Excitation > Current

By assigning zero current to the magnet it is assured that total current into and out of this magnet is zero. If there were more than one magnet, each one should have a separate excitation of zero amps. Ansoft Maxwell Field Simulator V12 – Training Manual

P1-78

Maxwell 2D: Open Circuit Back EMF, Magnet Loss Select Excitations, RMB to select Set Eddy Effect


P1-79

Maxwell 2D: Open Circuit Back EMF, Core Loss Select Excitations, RMB to select Set Core Loss. Add Core Loss for the Rotor and Stator


P1-80

Maxwell 2D: Open Circuit Back EMF, Solution Setup Modify the solution setup by selecting Setup1, RMB and select Properties

2

The time step is determined by: 1 deg 3600rev 360 deg 1 min 21600 deg * * = = sec 46.3u sec min rev 60 sec


The frequency is 240 Hz, which gives a period of 4.2 msec. Thus 10 msec is ~2.5 cycles P1-81

Maxwell 2D: Open Circuit Back EMF, Results Solve the transient problem by selecting Setup1 under Analysis, RMB to select Analyze After the problem is solved, click on Results, RMB to select Create Transient Report > Rectangular Plot


2 P1-82

Maxwell 2D: Open Circuit Back EMF, Results XY Plot 2

Ansoft Corporation

PMSM_OC_EMF

150.00

100.00

Y1 [V]

50.00

0.00

Curve Info InducedVoltage(PhaseA) Setup1 : Transient InducedVoltage(PhaseB) Setup1 : Transient

-50.00


-100.00

-150.00 0.00

2.00


4.00

Time [ms]

6.00

8.00

10.00

P1-83

Maxwell 2D: Open Circuit Back EMF, Results Click on Results, RMB to select Create Transient Report > Rectangular Plot

1 2 3


P1-84

Maxwell 2D: Open Circuit Back EMF, Results Core Loss

Ansoft Corporation

PMSM_OC_EMF

1.20


1.00

CoreLoss [kW]

0.80

0.60

0.40

0.20

0.00 0.00

2.00


4.00

Time [ms]

6.00

8.00

10.00 P1-85

Maxwell 2D: Rated Condition To solve the problem for the rated condition, select the Maxwell 2D design PMSM_OC_EMF, RMB and select Copy Select the project name PM_SyncMotor, RMB and select Paste Select the Maxwell 2D design PMSM_OC_EMF1, RMB and select Rename, and change the design name to PMSM_Rated

Delete the Mag_0, Rotor, and InnerRegion


P1-86

Maxwell 2D: New Rotor Geometry Select menu item Draw > User Defined Primitive > SysLib > RMxrpt > IPMCore. Modify the Values as shown below.


P1-87

Maxwell 2D: New Rotor Geometry Select the object IPMCore1 and then Edit > Arrange > Rotate

Select Modeler > Boolean > Split

Select Edit > Arrange > Rotate and use -45 degrees about the Z axis Select Modeler > Boolean > Split in the XZ Plane Keeping Fragments on

the Negative Side Select Edit > Arrange > Rotate and use +45 degrees about the Z axis Ansoft Maxwell Field Simulator V12 – Training Manual

P1-88

Maxwell 2D: New Rotor Geometry Select IPMCore1 and in the Properties window Name: Rotor Material: M19_26G_SF0.950

Select Rotor, RMB to select Edit > Copy In the drawing window, RMB to select Edit > Paste Select CreateUserDefinedPart under Rotor1, RMB to select Properties Change InfoCore to 1

Select Rotor1 and then Maxwell Model > Boolean > Separate Bodies. This will create two magnets. Change the name of the magnets to Mag_0 and Mag_1 and change their color.


P1-89

Maxwell 2D: New Rotor Geometry Select Rotor, RMB to select Edit > Copy In the drawing window, RMB to select Edit > Paste Select CreateUserDefinedPart under Rotor1, RMB to select Properties Change InfoCore to 2

Select Rotor1 and in the Properties window Name: Duct Material: Vacuum


P1-90

Maxwell 2D: Rated Condition, PM Setup Select Mag_0 and in the Properties window click on the material M19_26G_SF0.950 and select NdFe30 and then Clone Material(s)

2 1


P1-91

Maxwell 2D: Rated Condition, PM Setup Change the name to NdFe30_NV for North Pole V Core

Cartesian CS with the pole aligned with the X axis

Repeat the same for Mag_1


P1-92

Maxwell 2D: Rated Condition, PM Setup The drawing tree should look like this


P1-93

Maxwell 2D: Rated Condition, PM Setup A local coordinate system needs to be create for each magnet. Zoom into Mag_0. Select the Create Relative CS Icon

1

3

2


A local CS is create with X and Y axis as shown. Magnetization will be along the X axis P1-94

Maxwell 2D: Rated Condition, PM Setup Zoom into Mag_1. Select the Create Relative CS Icon

1

3 2


A local CS is create with X and Y axis as shown. Magnetization will be along the X axis P1-95

Maxwell 2D: Rated Condition, PM Setup Select Mag_0 and in the Properties Window change Orientation to

RelateiveCS1

Select Mag_1 and in the Properties Window change Orientation to

RelateiveCS2


P1-96

Maxwell 2D: Rated Condition, PM Mesh Ops. Select Mag_0 and Mag_1, RMB to assign mesh operations


P1-97

Maxwell 2D: Rated Condition, Excitation Select Rotor, Mag_0, Mag_1, and Duct. Select Moving1 under Motion, RMB to select Add Selected Object

Select PhaseA under Excitations, RMB to select Properties

163.299 * sin(2*pi*240*time+18.2635*pi/180)


P1-98

Maxwell 2D: Rated Condition, Excitation Select PhaseB and then PhaseC under Excitations, RMB to select

Properties.

VB = 163.299 * sin(2*pi*240*time+18.2635*pi/180-2*pi/3) VC = 163.299 * sin(2*pi*240*time+18.2635*pi/180-4*pi/3)


P1-99

Maxwell 2D: Rated Condition, Excitation Select Excitation, RMB to select Setup Y Connection

1 2 3


P1-100

Maxwell 2D: Rated Condition, Solution Setup Select MotionSetup1 under Model, RMB to select Properties and then Data to change the Initial Position, and then Mechanical to set the speed

Select Setup1 under Analysis, RMB and select Properties

This problem takes too long to solve during the class. The full solution can be downloaded from Ansoft’s FTP site: ftp://ftp.ansoft.com/download/ChinaTraining/PM_SyncMotor_Rated.zip Ansoft Maxwell Field Simulator V12 – Training Manual

P1-101

Maxwell 2D: Rated Condition, Results Ansoft Corporation

Winding Currents

Torque Quick Report

Ansoft Corporation

PMSM_Rated

600.00

3000.00

PMSM_Rated Curve Info Moving1.Torque Setup1 : Transient

500.00

2000.00 Curve Info Current(PhaseA) Setup1 : Transient Current(PhaseB) Setup1 : Transient

1000.00

400.00


Current(PhaseC) Setup1 : Transient

Y1 [A]

0.00

-1000.00

300.00

200.00

-2000.00

100.00

-3000.00

0.00

-4000.00

-100.00 0.00

50.00 Time [ms]

100.00

0.00

Core Loss

Ansoft Corporation

50.00 Time [ms]

100.00

PMSM_Rated

1.90


1.80

1.70

CoreLoss [kW]

1.60

1.50

1.40

1.30

1.20

85.00


87.50

90.00

92.50 Time [ms]

95.00

97.50

100.00

P1-102

Simplorer: Drive Design 1. Create Permanent Magnet Synchronous Machine Model from RMxprt: Double click on the original RMxprt design, click on menu RMxprt > Analysis Setup > Export …, choose “Simplorer Model” from the list and select a path where you want the model to be saved.

2. View the text of the model: Run Simplorer V7.0.5, in “SSC 7.0 Commander” window, click on Programs > Editor, open the model file we just created from RMxprt (*.sml).

Note: The model is not simply a linear model you can typically find from a textbook any more. It has nonlinear effect considered for both main and leakage flux magnetic paths. This model can also be used as both motor and generator. Ansoft Maxwell Field Simulator V12 – Training Manual

P1-103

Simplorer: Drive Design 3. Use the RMxprt created model in Simplorer as a generator: Open a new Simplorer Schematic, click on the “Add Ons” tab of the “ModelAgent”, click on “interfaces”, drag and drop “RMxprt” component on the schematic. Double click on the “RMxprtLink1” and then click on “Import Model (*.sml)”, browse to the location where the model was saved. Select the model > Open > OK, you should have the model show up like the following graph, with electrical nodes on the left and mechanical nodes on the right.


P1-104

Simplorer: Drive Design 4. Build the rest of the schematic like below. Details of each component are shown on the next page. B6U1

C := 1u

D3

D5

B6U

+ V

VM1 VALUE := 1000*(1+(t>0.02))

D1

C B A

C1

R_Load R := 1k

D6

D4

ROT2 RMXROT1

+

V_ROT1

RMxprtLink1

D2

ω

Back EMF (A-B

DC Link Voltage 84.00

92.00

50.00

50.00

R_Load.V [V]

0

VM1.V [V]

-50.00 -94.00

0 0

20.00m

0

40.00m

Rotor Position (Deg

20.00m

40.00m

Input Speed from Shaft

-3.55f

2.00k

-100.00 RMxprtLink1.Pos

-200.00

1.00k V_ROT1.OMEGA [rpm]

-300.00 0

-362.00 0


20.00m

40.00m

0

20.00m

40.00m

P1-105

Simplorer: Drive Design 5. ModelAgent > Add Ons tab > power > Line-commutated Converters > B6 Diode Bridge


P1-106

Simplorer: Drive Design 6. ModelAgent > Basics tab > Measurement > Electrical > Voltmeter 7. ModelAgent > Basics tab > Circuit > Passive Elements > Resistor and Capacitor

Note: Select the component and right mouse click to Flip or Rotate the component. Or you can use quick shortcut “F’ for Flip and “R” for Rotate.


P1-107

Simplorer: Drive Design 8. ModelAgent > Basics tab > Physical Domains > Mechanical > Velocity-Force-Representation > Rotational_V > Angular Velocity Source


P1-108

Simplorer: Drive Design 9. Click on Simulation > Parameters, or Alt + F12, or just double mouse click on any empty space on the schematic, define simulation parameters as seen from the picture.


P1-109

Simplorer: Drive Design 10. ModelAgent > Displays tab > Displays > 2D View Create plots of R_Load.V, VM1.V, RMxprtLink1.Pos, V_ROT1.OMEGA (rpm).

11. Run the simulation and view the results. Ansoft Maxwell Field Simulator V12 – Training Manual

P1-110

This completes the one day training course on permanent magnet synchronous machines using Ansoft’s RMxprt, Maxwell 2D and Simplorer


P1-111

Three-phase Induction Machine

3_FreqSweep Curve Info Efficiency Setup1 : Performance ScaleFactor='1' Efficiency Setup1 : Performance ScaleFactor='1.5' Efficiency Setup1 : Performance ScaleFactor='2' Efficiency Setup1 : Performance ScaleFactor='2.5' Efficiency Setup1 : Performance ScaleFactor='3' Efficiency Setup1 : Performance ScaleFactor='3.5' Efficiency Setup1 : Performance ScaleFactor='4' Efficiency Setup1 : Performance ScaleFactor='4.5' Efficiency Setup1 : Performance ScaleFactor='5' Efficiency Setup1 : Performance ScaleFactor='5.5' Efficiency Setup1 : Performance ScaleFactor='6' Efficiency Setup1 : Performance ScaleFactor='6.5' Efficiency Setup1 : Performance

80.00

70.00

60.00

Efficiency [percent]

50.00

40.00

30.00

20.00

10.00

XY Plot 1

Ansoft Corporation 300.00

-10.00 0.00

5000.00

RSpeed [rpm]

10000.00

15000.00

Winding Currents


6_Modified Curve Info Current(PhaseA) Setup1 : Transient Current(PhaseB) Setup1 : Transient Current(PhaseC) Setup1 : Transient

200.00

200.00

100.00

100.00 0.00

Curve Info Moving1.Torque Setup1 : Transient LengthFactor='1' Stator_ID='148mm' Volt_Mag='300V' Moving1.Torque Setup1 : Transient LengthFactor='1.2' Stator_ID='148mm' Volt_Mag='300V' Moving1.Torque Setup1 : Transient LengthFactor='1' Stator_ID='148mm' Volt_Mag='315V' Moving1.Torque Setup1 : Transient LengthFactor='1.2' Stator_ID='148mm' Volt_Mag='315V' Moving1.Torque Setup1 : Transient LengthFactor='1' Stator_ID='150mm' Volt_Mag='300V' Moving1.Torque Setup1 : Transient LengthFactor='1.2' Stator_ID='150mm' Volt_Mag='300V' Moving1.Torque Setup1 : Transient LengthFactor='1' Stator_ID='150mm' Volt_Mag='315V' Moving1.Torque Setup1 : Transient LengthFactor='1.2' Stator_ID='150mm' Volt_Mag='315V'

-100.00

-200.00

-300.00

-400.00

0.00

8_DesignSweep

Y1 [A]

90.00

Moving1.Torque [FootPounds]

XY Plot 2

Ansoft Corporation

0.00

-100.00

-200.00

-500.00 0.00


50.00

100.00 Time [ms]

150.00

200.00

-300.00 0.00

50.00

100.00 Time [ms]

150.00

200.00

P2-1

Contents I. RMxprt

IV. Modifying Maxwell 2D Design

Basic Theory Main Features Open and Run an Example and View Results Modify the Design and View New Results Create a Variable-Voltage Variable-Frequency Design

II. RMxprt -> Maxwell 2D Create an Maxwell 2D Design from RMxprt Review Maxwell 2D Transient Setup

III. Nominal Maxwell 2D Design Create an Maxwell 2D Design from RMxprt Change Simulation Time Step Set up Save Solution Fields Set Eddy Effects for All Bars Run Simulation and Review Quick Report Measure Position Change of Each Time Step Create Mesh/Field Plots and Animation

Notes:

Set up Variable Simulation Time Step Create output Variables for Stator Teeth and Stator Yoke Flux Densities Change Angular Velocity Set up Force Calculation Multi-frequency Core Loss Run Simulation and View New Results

V. Locked Rotor Simulation Change Initial Position and Angular Velocity Change Bar Conductivity Run Simulation and View Results

VI. Design Sweep Add Design Variables and Change Variable Values Set up Parametric Sweep Run Design Sweep and View Results

VII. Drive Design Create Induction Machine Model Drive Simulation

1. RMxprt/Maxwell V12 or higher is required 2. Basic knowledge of electric machine is required 3. Basic understanding of Finite Element is required Ansoft Maxwell Field Simulator V12 – Training Manual

P2-2

I. RMxprt Basic Theory X1

R1

X2

I1

U1

I2

RFe

Pm = 3 I 22 Tm =

R2 s

Xm

T2 = Tm − T fw

R2/s

P2 = T2ω 2

P1 = P2 + Pfw + PCu 2 + PFe + PCu 1 + Ps

Pm

ω

cos ϕ =

η=

P1 mU 1 I 1

P2 × 100% P1

Main Features Optimization of Winding and Coil Arrangement Winding Editor Supporting Any Single- and Double-Layer Windings More than 20 Slot Shapes for Single and Double Squirrel-Cage Rotor Pear type with round shoulder Pear type with tapered shoulder Trapezoid type with tapered shoulder Trapezoid type with round shoulder

Nonlinear and Distributed Parameters at Any Operation Condition Ansoft Maxwell Field Simulator V12 – Training Manual

P2-3

I. RMxprt Open and Run an Example and Review Results 1. Menu item File > Open: …\Ansoft\Maxwell12\Examples\RMxprt\indm3\yzd132-4 2. Save As to your preferred location and name, for example: “IM3_Calss” Change RMxprt Design name from “yzd132-4” to “1_Original” 3. Run simulation and view results


P2-4

I. RMxprt Modify the Design and View New Results 1. Copy the design “1_Orginal” and paste into the project, change the new design name to “2_RectWire” 2. Change the stator winding slot and wire to rectangular wire

3. Run simulation and view results Ansoft Maxwell Field Simulator V12 – Training Manual

P2-5

I. RMxprt Create a Variable-Voltage Variable-Frequency Design 1. Create three new design variables: ScaleFactor, FreqSweep and VoltSweep, click on menu item RMxprt > Design Properties

2. Assign VoltSweep and FreqSweep to Rated Voltage and Frequency respectively


P2-6

I. RMxprt 3. Create a Parametric sweep


P2-7

I. RMxprt 4. Run parametric sweep and view results: torque vs. speed

XY Plot 1


3_FreqSweep Curve Info OutputTorque Setup1 : Performance ScaleFactor='1' OutputTorque Setup1 : Performance ScaleFactor='1.5' OutputTorque Setup1 : Performance ScaleFactor='2' OutputTorque Setup1 : Performance ScaleFactor='2.5' OutputTorque Setup1 : Performance ScaleFactor='3' OutputTorque Setup1 : Performance ScaleFactor='3.5' OutputTorque Setup1 : Performance ScaleFactor='4' OutputTorque Setup1 : Performance ScaleFactor='4.5' OutputTorque Setup1 : Performance ScaleFactor='5' OutputTorque Setup1 : Performance ScaleFactor='5.5' OutputTorque Setup1 : Performance ScaleFactor='6' OutputTorque Setup1 : Performance ScaleFactor='6.5' OutputTorque Setup1 : Performance

80000.00

70000.00

OutputTorque [FootPounds]

60000.00

50000.00

40000.00

30000.00

20000.00

10000.00

0.00 0.00

5000.00

RSpeed [rpm]


10000.00

15000.00

P2-8

I. RMxprt 5. View results: efficiency vs. speed

XY Plot 2


3_FreqSweep Curve Info Efficiency Setup1 : Performance ScaleFactor='1' Efficiency Setup1 : Performance ScaleFactor='1.5' Efficiency Setup1 : Performance ScaleFactor='2' Efficiency Setup1 : Performance ScaleFactor='2.5' Efficiency Setup1 : Performance ScaleFactor='3' Efficiency Setup1 : Performance ScaleFactor='3.5' Efficiency Setup1 : Performance ScaleFactor='4' Efficiency Setup1 : Performance ScaleFactor='4.5' Efficiency Setup1 : Performance ScaleFactor='5' Efficiency Setup1 : Performance ScaleFactor='5.5' Efficiency Setup1 : Performance ScaleFactor='6' Efficiency Setup1 : Performance ScaleFactor='6.5' Efficiency Setup1 : Performance

80.00

70.00

60.00

Efficiency [percent]

50.00

40.00

30.00

20.00

10.00

0.00

-10.00 0.00


5000.00

RSpeed [rpm]

10000.00

15000.00

P2-9

II. RMxprt -> Maxwell 2D Create a Maxwell 2D Design from RMxprt 1. Create Maxwell design


2. Change the new Maxwell 2D design name to “4_Nominal”

P2-10

II. RMxprt -> Maxwell 2D 2. Review Maxwell 2D setups

Geometry

Motion setup Boundaries Excitations Materials Mesh operations Solve setup

Result plots

Ready to solve! Click on menu bar Maxwell 2D > Analyze All


P2-11

III. Nominal Maxwell 2D Design

1. Right mouse click on Setup1 under Design 1_Original > Analysis > Create Maxwell Design 2. Change design name to “5_Nominal2”


P2-12


3. 3. Change Change simulation simulation time time step step to to 0.001s 0.001s


4. Add Save Fields

5. Run simulation ……

P2-13

III. Nominal Maxwell 2D Design 6. View results: Output Torque vs. Time and Phase Currents vs. Time Torque

Ansoft Corporation

7. Review other Quick Reports

5_Norminal2

400.00


300.00

200.00


100.00

0.00

-100.00

-200.00

-300.00

-400.00

-500.00

-600.00 0.00

50.00

100.00 Time [ms]

150.00

Winding Currents


200.00

5_Norminal2 Curve Info Current(PhaseA) Setup1 : Transient Current(PhaseB) Setup1 : Transient Current(PhaseC) Setup1 : Transient

200.00

Y1 [A]

100.00

0.00

-100.00

-200.00

-300.00 0.00

50.00

100.00 Time [ms]

150.00


200.00

P2-14

III. Nominal Maxwell 2D Design 8. Add Position vs. Time plot 9. Change Trace Type to “Discrete”

10. Add Delta Marker to measure position change of each simulation time step, it is 8.7767 deg


P2-15


11. Plot mesh: CTRL+A to select all objects > right mouse click > Plot Mesh 12. Menu bar View > Grid Setting, turn Grid invisible 13. Menu bar View > Coordinate System > Hide


14. Double click on bottom left corner to change at what time step you want to view the plot

P2-16

III. Nominal Maxwell 2D Design 15. Plot fields: CTRL+A to select all objects > right mouse click > Fields > A/H/B etc. 16. Right mouse click on the picture > Copy Image, try paste into Microsoft Word or Power Point 17. Uncheck Plot Visibility to avoid all plots on top of each other


P2-17

III. Nominal Maxwell 2D Design 18. Create animation: right mouse click on the item under Field Overlays > Animate 19. Export the animation to .avi or .gif format and import into Power Point for presentation


P2-18

IV. Modifying Maxwell 2D Design Set up a Variable Simulation Time Step 1. Copy Design 5, paste and change name to “6_Modified” 2. Click on menu bar Maxwell 2D > Design Datasets 3. Add and edit design dataset “Time_Step” 4. Double click “Setup1” under “Analysis”, change Time step to “pwlx(Time_Step, time)”


P2-19

IV. Modifying Maxwell 2D Design Change Angular Velocity 1. Double click on MotionSetup1 under Model, click on “Mechanical” tab in the Motion Setup window

2. Change Angular Velocity to 1350 rpm

3. Check “Consider Mechanical Transient if you want to simulate mechanical transient


P2-20

IV. Modifying Maxwell 2D Design Set up Force Calculation 1. Select object “Bar” > right mouse click > Assign Parameters > Force 2. There is no need to assign Torque calculation, moving torque is assigned automatically in Transient Solver with rotational motion 3. You can assign as many Force calculations as you may need. This is different from V11 2D, where the Force calculation is “hidden” in Transient and you can only calculate one force at a time


P2-21

IV. Modifying Maxwell 2D Design Create Output Variables for Stator Teeth and Stator Yoke Flux Densities 1. Zoom in stator tooth and yoke area, draw two lines called “Stator_Tooth” and “Stator_Yoke” 2. Pay attention to use “Snap to” feature, like to vertex, to center point, etc.

3. In the next few steps we will use “Calculator” to create “Named Expression”: “Stator_Tooth_Flux” and “Stator_Yoke_Flux”

4. Click on menu item Maxwell 2D > Fields > Calculator


P2-22

IV. Modifying Maxwell 2D Design

5. Quantity > B, Mag, Geometry > Line > Stator_Tooth, integration, Number, 0.25 (stator stack length in meters), * 6. Add, Stator_Tooth_Flux 7. Do the same for “Stator_Yoke_Flux”


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IV. Modifying Maxwell 2D Design Multi-frequency Core Loss 1. Select both Rotor and Stator, click on material M19_24G_SF0.920 button in the Properties window 2. Click on Clone Material(s), change material name and Electrical Steel as Core Loss Type


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IV. Modifying Maxwell 2D Design Multi-frequency Core Loss 3. Type in Mass Density = 7650kg/m^3

4. Click on Calculate Properties for > Core Loss versus Frequency


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IV. Modifying Maxwell 2D Design Multi-frequency Core Loss 50Hz

100Hz 200Hz

400Hz


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IV. Modifying Maxwell 2D Design Run Simulation and View New Results 1. Run simulation 2. View existing plots: torque, current, position vs. time, compare with results from Design 5 Torque

Ansoft Corporation

Ansoft Name Corporation X

6_Modified

1800.00 m1 44.0000 m2


200.00

1600.00

100.00

1400.00

0.00

1200.00

Moving1.Position [deg]


300.00

-100.00

-200.00

-300.00

45.0000

Position Quick Report

Y 356.4000 364.5000

6_Modified Curve Info Moving1.Position Setup1 : Transient

1000.00

800.00

600.00

Winding Currents


6_Modified Curve Info Current(PhaseA) Setup1 : Transient Current(PhaseB) Setup1 : Transient Current(PhaseC) Setup1 : Transient

-400.00

-500.00 0.00

50.00

200.00

100.00 Time [ms]

150.00

200.00

m2 m1

200.00

Name 0.00 d(m1,m2)

100.00

Y1 [A]

400.00

Delta(X) 1.0000 0.00

Delta(Y) 8.1000

Slope(Y) 8.1000

InvSlope(Y) 0.1235

50.00

100.00 Time [ms]

150.00

200.00

0.00

-100.00

-200.00

-300.00 0.00

50.00


100.00 Time [ms]

150.00

200.00

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IV. Modifying Maxwell 2D Design XY Plot 1


6_Modified Curve Info Stator_Tooth_Flux Setup1 : Transient Stator_Yoke_Flux Setup1 : Transient

0.006

3. Create Stator tooth/yoke flux density plots

0.005

Y1

0.004

4. Right mouse click on Results > Create Fields Report > Rectangular Plot

0.003

0.002

0.001

0.000 0.00


50.00

100.00 Time [ms]

150.00

200.00

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IV. Modifying Maxwell 2D Design 6. Create Core Loss vs. Time plot

5. Create Force vs. Position plot

XY Plot 3


Force_Bar


6_Modified Curve Info CoreLoss Setup1 : Transient

6_Modified Curve Info Force_Bar.Force_mag Setup1 : Transient Force_Bar.Force_x Setup1 : Transient Force_Bar.Force_y Setup1 : Transient

70.00

60.00

500.00

CoreLoss [W]

Y1 [newton]

50.00

0.00

40.00

30.00

20.00

-500.00

10.00

-1000.00 0.00

200.00

400.00

600.00

800.00 1000.00 Moving1.Position [deg]

1200.00

1400.00


1600.00

1800.00

0.00 0.00

50.00

100.00 Time [ms]

150.00

200.00

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V. Locked Rotor Simulation

1. Copy Design 6, paste and change name to “7_LockedRotor” 2. Double click on MotionSetup1 and change Initial Position and Angular Velocity


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V. Locked Rotor Simulation

3. Change Bar Conductivity to Simulate High Temperature Effect, use “cast_aluminum_75C” 4. Run Simulation and View Results Torque


7_LockedRotor Curve Info Moving1.Torque Setup1 : Transient

400.00

300.00

Winding Currents

Ansoft Corporation


300.00

7_LockedRotor Curve Info Current(PhaseA) Setup1 : Transient Current(PhaseB) Setup1 : Transient Current(PhaseC) Setup1 : Transient

200.00

200.00 100.00

0.00

100.00

Y1 [A]

-100.00

0.00

-200.00

-100.00 -300.00 0.00

50.00

100.00 Time [ms]

150.00

200.00

-200.00

-300.00 0.00


50.00

100.00 Time [ms]

150.00

200.00

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VI. Design Sweep 1. Copy Design 6 and paste into the project, change design name to “8_DesignSweep”Variables 2. Right mouse click on the name of the design > Design Properties, add “LengthFactor = 1.2”


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VI. Design Sweep

3. Click menu bar Maxwell 2D > Design Settings, change Model Depth

4. Click on PhaseA and change Resistance 5. Do the same for PhaseB and PhaseC resistance


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VI. Design Sweep

6. Click on PhaseA and replace voltage with “Volt_Mag” > Enter > with default value 315V

315V

7. Do the same for PhaseB and PhaseC voltage


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VI. Design Sweep 8. Click on CreateUserDefinedPart under Stator, change DiaGap in the Properties window to “Stator_ID”

9. Change the default value to 150mm


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VI. Design Sweep 10. Right mouse click on Optimetrics > Add > Parametric


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VI. Design Sweep 11. Right mouse click on Optimetrics > ParametricSetup1 > Analyze 12. View Results : right mouse click on Results > Create Transient Report > Rectangular Report

XY Plot 1


8_DesignSweep

200.00


100.00

0.00

Curve Info Moving1.Torque Setup1 : Transient LengthFactor='1' Stator_ID='148mm' Volt_Mag='300V' Moving1.Torque Setup1 : Transient LengthFactor='1.2' Stator_ID='148mm' Volt_Mag='300V' Moving1.Torque Setup1 : Transient LengthFactor='1' Stator_ID='148mm' Volt_Mag='315V' Moving1.Torque Setup1 : Transient LengthFactor='1.2' Stator_ID='148mm' Volt_Mag='315V' Moving1.Torque Setup1 : Transient LengthFactor='1' Stator_ID='150mm' Volt_Mag='300V' Moving1.Torque Setup1 : Transient LengthFactor='1.2' Stator_ID='150mm' Volt_Mag='300V' Moving1.Torque Setup1 : Transient LengthFactor='1' Stator_ID='150mm' Volt_Mag='315V' Moving1.Torque Setup1 : Transient LengthFactor='1.2' Stator_ID='150mm' Volt_Mag='315V'

-100.00

-200.00

-300.00

-400.00

-500.00 0.00


50.00

100.00 Time [ms]

150.00

200.00

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VII. Drive Design 1. Create Induction Machine Model from RMxprt: Double click on the RMxprt design “1_Original”, click on menu RMxprt > Analysis Setup > Export …, choose “Simplorer Model” from the list and select a path where you want the model to be saved.

2. View the text of the model: Run Simplorer V7.0.5, in “SSC 7.0 Commander” window, click on Programs > Editor, open the model file we just created from RMxprt (*.sml).

Note: The model is not simply a linear model you can typically find from a textbook any more. It has nonlinear effect considered for both main and leakage flux magnetic paths. It also has eddy current effect considered for bars in order to more accurately model start-up performance of this machine. Ansoft Maxwell Field Simulator V12 – Training Manual

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VII. Drive Design 3. Use the RMxprt created model in Simplorer: Open a new Simplorer Schematic, click on the “Add Ons” tab of the “ModelAgent”, click on “interfaces”, drag and drop “RMxprt” component on the schematic. Double click on the “RMxprtLink1” and then click on “Import Model (*.sml)”, browse to the location where the model was saved. Select the model > Open > OK, you should have the model show up like the following graph, with electrical nodes on the left and mechanical nodes on the right.


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VII. Drive Design 4. Build the rest of the schematic like below. Details of each component are shown on the next page. + VM1

3PHAS A * sin (2 * pi * f * t + PHI + phi_u)

~

PHI = 0°

~

PHI = -120°

~

PHI = -240°

V

MASS_ROT1

FM_ROT1 RMxprtLink1

AM1 A

J := 0.2 kg m %

T

ROT1 A B

ROT2

C N

T

RMX

LoadStep

STEP1 THREE_PHASE1

Line to Line Voltage

Torque VM1.V

472.00

FM_ROT1.TORQUE [Nm] STEP1.VAL

537.50 0

200.00

-540.00

-57.50 0

500.00m

1.00

0

1.00

No. of Iterations

Speed

Phase A Current 251.00

500.00m

AM1.I

SIMPARAM1

1.52k

25.00

1.00k 0 MASS_ROT1.OMEGA [rpm] 0

-208.00 0

500.00m


1.00

0

500.00m

1.00

10.00 SIMPARAM1.Iterations 990.00m 0

1.00

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VII. Drive Design 5. ModelAgent > Add Ons tab > power > Power System and Cable Models > Ideal Three Phase Power Supply


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VII. Drive Design 6. ModelAgent > Basics tab > Measurement > Electrical > Voltmeter and Ammeter 7. ModelAgent > Basics tab > Measurement > Mechanical > Velocity-Force-Representation > Torque Meter

Note: Select the component and right mouse click to Flip or Rotate the component. Or you can use quick shortcut “F’ for Flip and “R” for Rotate.


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VII. Drive Design 8. ModelAgent > Basics tab > Blocks > Sources Block > Step Function


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VII. Drive Design 9. ModelAgent > Basics tab > Physical Domains > Mechanical > Velocity-Force-Representation > Rotational_V > Mass


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VII. Drive Design 10. ModelAgent > Basics tab > Physical Domains > Mechanical > Velocity-Force-Representation > Rotational_V > Torque Source


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VII. Drive Design 11. ModelAgent > Basics > Tools > Simulator Parameters

12. Click on Simulation > Parameters, or Alt + F12, or just double mouse click on any empty space on the schematic, define simulation parameters as seen from the picture.


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VII. Drive Design 13. ModelAgent > Displays tab > Displays > 2D View Create plots of VM1.V, AM1.I, FM_ROT1.TORQUE, STEP1.VAL, MASS_ROT1.OMEGA (in rpm) and SIMPARAM1.Iterations.

14. Run the simulation and compare the results with RMxprt. Ansoft Maxwell Field Simulator V12 – Training Manual

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This completes the one day training course on Three-phase Induction Machine using Ansoft’s RMxprt, Maxwell 2D and Simplorer


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Topic – Motor Application Note

Study of a Permanent Magnet Motor with MAXWELL 2D: Example of the 2004 Prius IPM Motor

Ansoft Maxwell Field Simulator

Topic – Motor Application Note Study of an electrical machine The Electro Mechanical software package provided by Ansoft enables extensive electrical malchinesimulation. This application note details the simulaton of an electrical machine with Maxwel2D. We will cover static and transient simulations. This application note will use the 2004 Toyota Prius motor as basis. It is a 8pole permanent magnet motor with embedded magnets. The single layer windings are made of 3 phases. The stator has 48 slots. This motor is public, we therefore have the full set of parameters. We will also use Oak Ridge National Laboratory testing results in this note. Note: This application has not been done with the collaboration of Toyota

References: Report on Toyota/Prius Motor Torque Capability, Torque Property, No-Load Back EMF, and Mechanical Losses, J. S. Hsu, Ph.D., C. W. Ayers, C. L. Coomer, R. H. Wiles Oak Ridge National Laboratory Report on Toyota/Prius Motor Design and manufacturing Assessment J. S. Hsu, C. W. Ayers, C. L. Coomer Oak Ridge National Laboratory Evaluation of 2004 Toyota Prius Hybrid Electric Drive System Interim Report C. W. Ayers, J. S. Hsu, L. D. Marlino, C. W. Miller,G. W. Ott, Jr.,C. B. Oland Oak Ridge National Laboratory



Overview of the Study:

GETTING STARTED Creating the 3D Model Reducing the size of the 3D Model Material properties of the machine Applying Master/Slave Boundary Condition

STATIC ANALYSIS

DYNAMIC ANALYSIS

COGGING TORQUE



Getting Started Launching Maxwell 1.

To access Maxwell, click the Microsoft Start button, select Programs>Ansoft>Maxwell 12.

Setting Tool Options To set the tool options: Note: In order to follow the steps outlined in this example, verify that the following tool options are set : 1. Select the menu item Tools > Options > Maxwell 2D Options 2. Maxwell Options Window: 1. Click the General Options tab Use Wizards for data entry when creating new boundaries: ; Checked Duplicate boundaries with geometry: ; Checked 2. Click the OK button 3. Select the menu item Tools > Options > Modeler Options. 4. 3D Modeler Options Window: 1. Click the Operation tab Automatically cover closed polylines: ; Checked 2. Click the Drawing tab Edit property of new primitives: ; Checked 3. Click the OK button


Topic – Motor Application Note Opening a New Project To open a new project: 1. In an Maxwell window, click the icon on the Standard toolbar, or select the menu item File > New. 2. Right mouse click on the project name, then select the menu item Rename. Change the project name to Prius 3. Select the menu item Project > Insert Maxwell Design, or click on the icon 4. Right mouse click on Maxwelldesign1 and select Rename. Change the name to 1_Whole_Motor

Set Model Units Select the menu item 3D Modeler > Units. Select Units: mm (millimeters)



Creating the 2D Model Maxwell has number of User Defined Primitives for motor parts. These primitives can describe all the main parts of motors.

Create the Stator: A User Defined Primitive will be used to create the stator Select the menu item Draw > User Defined Primitive > Syslib > Rmxprt >

SlotCore Use the values given in the panel below to create the stator



Creating the 2D Model (Continued) Click on the just created object in the drawing window and in the panel on the left change its name from SlotCore1 to Stator Note: the material will be applied afterwards

Create the Rotor A User Defined Primitive will be used to create the rotor Select the menu item Draw > User Defined Primitive > Syslib > Rmxprt >

IPMCore Use the values given in the panel next page to create the rotor



Creating the 2D Model (Continued)

Click on the just created object in the drawing window and in the panel on the left change its name from IPMCore1 to Rotor

Create the Magnets The same User Defined Primitive can be used to create the magnets, but with different parameters. UDPs can be computed to generate different topologies. Select the object Rotor. Copy and paste the object using the Ctrl+C, Ctrl+V commands. An object Rotor1 is created



Creating the 2D Model (Continued) On the modeler tree, double click on the command ‘CreateUserDefinedPart’ of the object Rotor1

Change the InfoCore line from 0 (Core) to 1 (Magnets)

Change the name of the object from Rotor1 to Magnets Change the magnets color from default to a light red.



Creating the 2D Model (Continued) Create the Windings An User Defined Primitive will also be used to create the windings. Select the menu item Draw > User Defined Primitive > Syslib > Rmxprt > LapCoil Use the values given in the panel below to create the coil

Change the Material from vacuum to Copper Select the object LapCoil1, change its color to yellow



Creating the 2D Model (Continued) Select the object LapCoil1, and to apply a rotation of 7.5 deg along the Z axis, right mouse click, and select the menu item Edit > Arrange > Rotate or use the icon.

Select the object LapCoil1. This coil constitutes the first coil of Phase A. We now duplicate this coil to create the first coils of Phase C and B. Right Mouse click, and select the menu item Edit > Duplicate > Around Axis or use the icon.

Change the Name of objects LapCoil1_1 and LapCoil1_2 to PhaseC and PhaseB. Change the color of PhaseC to dark green and the color of PhaseB to light blue. Rename Lapcoil1 to PhaseA.



Creating the 2D Model (Continued)

Select the objects PhaseA, PhaseB and PhaseC. Right Mouse click, and select icon. Enter 45 the menu item Edit > Duplicate > Around Axis or use the degrees and 8 for the total number. This will create all the required coils.



Creating the 2D Model (Continued) The geometry of the motor is completed.

Depending on the solver and the motor performance data that we want to look at, we might have to add more objects (for meshing or movement setting). Save the project. Click on the Maxwell design ‘1_Whole_motor’, right mouse click and select ‘Copy’.

Click on the project name, right mouse click and select ‘Paste’. Change the copied design to 2_Partial_motor. We can take advantage of the topology of the motor to reduce the size of the problem. This motor has 8 pair of poles. We can only use one height of the motor. This is valid because the stator has: 48 slots (8 is a divider of 48). The 3-phase winding has also a periodicity of 45 degrees. From now on, the Maxwelldesign ‘2_Partial_motor’ will be used. We have saved a copy of the whole geometry as it will be used later for other studies.



Reducing the size of the 2D Model (Continued) Select all the objects from the modeler tree (or you can use the ctrl-A command). Right mouse click and select Edit > Boolean > Split or use the toolbar icon . Select the XZ plane and keep the positive side.

Note: During the process, a lot of messages will appear in the dialog box. These messages inform that some objects no longer exist as they entirely lie outside the remaining model. We obtain half of the motor. Maintain the objects selected, right mouse click and . Enter -45 deg for select Edit > Arrange > Rotate or select the toolbar icon the rotation around the Z axis.

Maintain the objects selected, Right mouse click and select Edit > Boolean > Split or use the toolbar icon . Select the XZ plane and keep the negative side. Maintain the objects selected, right mouse click and select Edit > Arrange > . Enter 45 deg for the rotation around the Z Rotate or select the toolbar icon axis



Reducing the size of the 2D Model (Continued) The 3D model now looks like below

Rename PhaseA to PhaseA1 and PhaseA_7 to PhaseA2. Rename PhaseB, PhaseB_7, PhaseC and PhaseC_7 to PhaseB1, PhaseB2, PhaseC1 and

PhaseC2.

We can now create the Region around the motor. Most of the flux is concentrated within the motor, so we do not need to have a large Region.

Select Draw > Line 1. Using the coordinate entry field, enter the box position X: 0.0, Y: 0.0, Z: 0.0, Press the Enter key 2. Using the coordinate entry field, enter the relative size of the box dX: 200.0, dY: 0.0, dZ: 0.0, Press the Enter key 3. Click Enter a second time to finish the drawing



Reducing the size of the 2D Model (Continued) Select Polyline1. Right mouse click and select Edit > Sweep > Around Axis. Enter the parameters as specified in the panel below:

Rename the Region from Polyline1 to Region. Make sure that Vacuum is the selected material. Also, you might want to modify the render of the Region by increasing the transparency.



Material properties of the motor Permanent Magnets characterization. The Prius Permanent Magnets (PMs) are high-strength magnets. In order to define PMs magnetization orientation, we need to create separate objects for each magnet. Select the object Magnets. Right mouse click, select Edit > Boolean > Separate Bodies. Rename the objects from Magnets to PM1 and from Magnets_Separate1 to PM2. Since the magnets will rotate, the orientation cannot be given through fixed coordinate systems (CS). The use of face CS is required. Face CS are CS that are attached to the face of an object. When the object moves, the Face CS also moves along with the object. The Prius’s PMs are oriented as shown below. Therefore, we will create a face CS for each magnet.

Switch the select mode from Object to Face by clicking on the ‘f’ button or by using the toolbar icon:



Material properties of the motor (Continued) Select the face of the magnet PM1 as shown below

To create the face CS attached to this face: 1. Select the menu item 3D Modeler > Coordinate System > Create > Face CS or select the toolbar icon 2. The modeler is in draw mode. It expects the center of the face CS that has to be on the selected plane to be selected. Snap the mouse pointer to one of the corner of the face, using the “snap to vertex symbol”” . This defines the CS center.

3.

You need to enter the direction of the X axis. Snap the mouse point at another vertex of the face as shown below



Material properties of the motor (Continued) The face CS is created. Its default name is FaceCS1. Change its name from FaceCS1 to PM1_CS.

Repeat the same operation to create the face CS PM2_CS attached to PM2. Make sure to have the X axis looking toward the air gap

Reset the working CS to the Global CS by clicking on Global as shown below.



Material properties of the motor (Continued) Edit the attributes of the object PM1. Modify the Orientation of the object by selecting the PM1_CS coordinate system. This CS will be the reference for the magnetization direction.

To enter into the material database, click on the Material button (the default material is Vacuum). The Prius magnet is not part of the default library, so click on the Add material button



Material properties of the motor (Continued) We have a special menu to enter Permanent Magnet parameters. At the bottom of the View/Edit material window, select the “Permanent Magnet” entry.

Enter the values given below to define the magnet strength



Material properties of the motor (Continued) Change the material name to N36Z_20. If the coordinate system PM1_CS is such that the X axis goes in the opposite direction of the air gap accordingly to the image below, leave the X orientation to 1 and 0 for the Y and Z components. If the X axis was in the opposite direction, you would need to enter -1 for the X component.

Click on the Validate button before closing the window to check the material definition. Edit the attributes of the object PM2. Modify the Orientation of the object by selecting the PM2_CS coordinate system. This CS will be the reference for the magnetization direction. If the definition of PM2_CS is consistent with PM1_CS ( X axis in the direction of the air gap), you can use the same material for N36Z_20 for PM2. If it is not the case, you can clone the material N36Z_20 and change the orientation to be consistent with the PM2_CS axis.



Material properties of the motor (Continued) Steel definition The stator and rotor shares the same material. Select the objects Stator and Rotor. Edit their attributes, change the affected material. In the material database, add a new material called M19_29G. The steel is non linear. To enter the non-linear B-H Characteristic, change the Relative Permeability from “Simple” to “Nonlinear”

Click on the BH curve button in the Value column. The BH curve entry window appears



Material properties of the motor (Continued) Enter the B-H characteristics with the values given below

H 0 22.28 25.46 31.83 47.74 63.66 79.57 159.15 318.3 477.46 636.61 795.77 1591.5 3183 4774.6 6366.1 7957.7 15915 31830 111407 190984 350138 509252 560177.2 1527756


B 0 0.05 0.1 0.15 0.36 0.54 0.65 0.99 1.2 1.28 1.33 1.36 1.44 1.52 1.58 1.63 1.67 1.8 1.9 2 2.1 2.3 2.5 2.563994494 3.779889874


Material properties of the motor (Continued) We neglect the Eddy current in this example, therefore we leave the conductivity to 0. Validate the material before exiting the View/Edit material window

Make sure that M19_29G is affected to the Rotor and Stator.


Topic – Motor Application Note Coreloss This section is only necessary if you wish to compute the coreloss of the motor. In the Transient solver, we are able to compute coreloss (or hystereris loss), stranded loss and eddy current loss (or proximity loss). We will only consider coreloss in this document. We need to enter the loss values of the steel. A dedicated menu enables the user to enter the data. Extend the project tree, and double click the Material definition of the Steel M19_29G

Use the pull down menu to enable core loss for Electrical Steel material


Topic – Motor Application Note Coreloss (Continued) The Maxwell solver requires the coefficients Kh, Kc, Ke and Kdc. A special menu allows the coefficients to be derived from manufacturer core loss data Select at the bottom of the material definition window from the pull down menu Core Loss versus Frequency

The Core Loss versus Frequency menu pops up. We provide the data for several frequencies: 1. Select W/kg for the Core Loss Unit 3 2. Enter 7872 kg/m for the Mass density of the Steel 3. Enter 50 Hz in the Edit window 4. Click on Add 5. Click on Edit Dataset in the Frequency Window


R

Topic – Motor Application Note Coreloss (Continued) Enter the loss curve at 50 Hz: 50 Hz B 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8

P 0 0.03 0.07 0.13 0.22 0.31 0.43 0.54 0.68 0.83 1.01 1.2 1.42 1.7 2.12 2.47 2.8 3.05 3.25

Accept the setting Using the same method enter the loss curves for 100, 200, 400, 1000 Hz 100Hz B

200Hz P

B

400Hz P

B

1000Hz P

B

P

0

0

0

0

0

0

0

0

0.1

0.04

0.1

0.09

0.1

0.21

0.1

0.99

0.2

0.16

0.2

0.37

0.2

0.92

0.2

3.67

0.3

0.34

0.3

0.79

0.3

1.99

0.3

7.63

0.4

0.55

0.4

1.31

0.4

3.33

0.4

12.7

0.5

0.8

0.5

1.91

0.5

4.94

0.5

18.9

0.6

1.08

0.6

2.61

0.6

6.84

0.6

26.4

0.7

1.38

0.7

3.39

0.7

9

0.7

35.4

0.8

1.73

0.8

4.26

0.8

11.4

0.8

46

0.9

2.1

0.9

5.23

0.9

14.2

0.9

58.4

1

2.51

1

6.3

1

17.3

1

73

1.1

2.98

1.1

7.51

1.1

20.9

1.1

90.1

1.2

3.51

1.2

8.88

1.2

24.9

1.3

4.15

1.3

10.5

1.3

29.5

1.4

4.97

1.4

12.5

1.4

35.4

1.5

5.92

1.5

14.9

1.5

41.8


Topic – Motor Application Note Coreloss (Continued) The coreloss coefficient are automatically calculated

Accept the setting. The material definition now includes the coreloss coefficients



Applying Master/Slave Boundary Condition The Master and Slave boundary condition takes advantage of the periodicity of the motor. Two planes are to be defined: the master and slave planes. The Hfield at every point on the slave surface matches the (plus or minus) H-field at every point on the master surface. Select the object Region from the active view. Right mouse click, then select View> Show In Active View as shown below

Change the Select mode to Edge

Select one of the bounding line of the Region



Applying Master/Slave Boundary Condition (Con’d) Right mouse click, select Assign Boundary > Master

The vector u is defined correctly. Accept the setting.

Select the opposite edge of the Region



Applying Master/Slave Boundary Condition (Cont’d)

Right mouse click, select Assign Boundary > Slave

1.

2.

3.

4.

We first need to give the reference of the master condition. For the Master Boundary, since we haven't changed the default name, Select Master1 Select Swap direction for the u vector definition if the vector u does not have the same direction than the u vector of the Master condition. The model represents one pole out of height. Since we represent an odd number of poles, the condition at the slave surface is Slave = -Master Accept the set up



Applying Zero Vector Potential Boundary Condition At the limit of the Region, select the five segments of the outside limit of the Region. Use the Ctrl button to allow multi selections

Right Mouse Click, Select Assign Boundary > Vector Potential 1. 2.

Put 0 Weber/m for the value Name the condition Zero_Flux



STATIC ANALYSIS We will study the different static parameters of the motor. Save the project. Click on the Maxwell design ‘2_Partial_motor’, right mouse click and select ‘Copy’.

Click on the project name, right mouse click and select Paste. Change the copied design to ‘3_Partial_motor_MS’.

No Load Study The first analysis that will be performed consists in computing the fields due to the permanent magnets. The Coils are not needed in the model since no current is defined. Select the 6 coils. Then, Uncheck the radio button “Model” from the property window. Note that the Name of object line is empty since we have selected several objects.

Leave the Coils selected, and Hide the coils by selecting the menu item View > Hide Selection > Active view or using the toolbar button


Topic – Motor Application Note se Apply Mesh Operations The adaptive meshing is very effective, so it is not necessary to enter dedicated mesh operations. However, it is always a good idea to start with a decent initial mesh in order to reduce time computation since we know where the mesh needs to be refined for a motor. The non linear resolution will be faster with a small aspect ratios for the elements in the steel. Select the Rotor. Right Mouse Click and Select Assign Mesh Operation > Inside

Selection > Length Based

Restrict the length of elements to 5 mm. Rename the mesh operation Rotor Select the Stator. We want to minimize the number of elements for the curved line of the slots. Right Mouse Click and Select Assign Mesh Operation > Surface Approximation. Input 30deg for the Maximum surface deviation Select 5 for the Maximum aspect Ratio. Rename the mesh operation SA_Stator


Topic – Motor Application Note Apply Mesh Operations (Continued) Select PM1 and PM2. Right Mouse Click and Select Assign Mesh Operation >

Inside Selection > Length Based

Restrict the length of elements to 3 mm. Rename the mesh operation Magnets

Apply Torque computation Select the objects PM1, PM2 and Rotor. Right mouse click and select Assign Parameters > Torque


Topic – Motor Application Note Add an Analysis Setup From the project manager, right mouse click on Analysis and select Add Solution

Setup:

1. 2. 3. 4.

Enter 10 for the maximum number of passes Enter 0.1% for the error In the convergence panel, enter 15% for the refinement Make sure that the Non Residual is set to 0.0001%. Click Ok to record the analysis setup

Analyse Right mouse click on the setup et select Analyze or click on the


icon.

Topic – Motor Application Note Post processing The computation takes 7 passes to converge. The Convergence panel can be seen by right mouse clicking on Setup1, selecting the menu item Convergence

Torque value. Select the Solutions tab, the torque is given for a one meter depth motor. The torque for the full motor needs to be multiplied by 8 (symmetry factor), then by 0.082 (to account for the motor length). This gives 2.5mN.m, which sounds reasonable: the value is very small in regards to the full load operation. Different angles between the rotor and the stator would give different values.


Topic – Motor Application Note Post Processing (Cont’d) Plot magnetic flux density. Select the Rotor, Stator, PM1, PM2 right mouse click, select All Object Faces. Right mouse click again and select Fields > B > Mag_B. We obtain the distribution of B on the objects. The steel is highly saturated close to the magnets as expected. This saturations appears just because of the magnets strengths.

Plot the magnetic flux strength H in the air gap. We need to draw a postprocessing line to view the field: 1. Draw an arc. Select the menu item Draw > Arc > Center Point or use the corresponding toolbar icon 2.

3.

Accept to continue to draw a non model object. This will not invalidate the existing solution

Enter the center of the arc: 0,0,0 mm and hit enter


Topic – Motor Application Note Post Processing (Cont’d) 4.

Enter the first point of the arc. This point is at the middle of the air gap on the YZ plane. Enter 80.575, 0 , 0 mm and hit enter.

5.

Enter the last point of the arc. This point lies on the plane XY, with a 45° angle with the X- axis. 80.575/ √2= 56.70996(…). Enter 56.70996, 56.70996, 0 mm and hit enter.

6.

To finish the arc, move the mouse on the drawing area, right mouse click, and select the menu entry done

7.

Name the polyline airgap_arc and accept the object



9.

10.

A new folder ‘Lines’ has appeared on the object tree, containing the new defined arc.

Select the line airgap_arc, move the mouse on the drawing area, right mouse click, then select the menu item Fields > H > H_vector.

Accept the Field plot setting



The vector plot of H appears with the default setting. To customize the display, double click on the scale zone:

12.

You can modify the default settings in the different tabs like below:



Full Load Study Save the project. Click on the Maxwell design ‘3_Partial_motor_MS’, right mouse click and select ‘Copy’. Click on the project name, right mouse click and select Paste. Change the copied design to ‘4_Partial_motor_MS2’. In this design, we apply current in the coils: we need to include the coils in the model. Select the 6 coils from the modeler tree. In the property window, select the radio button Model.

Unhide the coils by selecting the menu item View> Show selections> All views

Apply Excitations The coils are partially represented in the model. We need to enter the current that flows in and out inside each coil. The excitation is realized through a balanced three phase system. For instance, in our example, we apply: 1500 A to PhaseA -750 A to PhaseB -750 A to PhaseC. In the Magnetosatic solver, the sources are given in terms of currents. We do not need to model each turn at this stage; therefore we only enter the total current in each phase. The number of turns and the electrical topology are only taken into account for the inductances calculation.


Topic – Motor Application Note Apply Excitations (Cont’d) Switch the selection mode to face Enter Excitation for Coil PhaseA2: 1. Select the PhaseA2

2. 3. 4. 5. 6.

Right mouse click, select the menu item Apply Excitation > Current Rename the Excitation PhaseA2 Enter 1500A As the default current direction plotted in red is good, leave Positive Validate the Excitation


Topic – Motor Application Note Apply Excitations (Cont’d) Switch the selection mode to face Enter Excitation for Coil PhaseA1 1. Select the PhaseA1

2. 3. 4. 5. 6.

Right mouse click, select the menu item Apply Excitation > Current Rename the Excitation PhaseA1 Enter 1500A As the default current direction plotted in red is good, leave Positive Validate the Excitation


Topic – Motor Application Note Apply Excitations (Cont’d) Switch the selection mode to face Enter Excitation for Coil PhaseC2 1. Select the PhaseC2

2. 3. 4. 5. 6.

Right mouse click, select the menu item Apply Excitation > Current Rename the Excitation PhaseC2 Enter -750A As the default current direction plotted in red is not good, choose Negative Validate the Excitation


Topic – Motor Application Note Apply Excitations (Cont’d) Switch the selection mode to face Enter Excitation for Coil PhaseC1 1. Select the PhaseC1

2. 3. 4. 5. 6.

Right mouse click, select the menu item Apply Excitation > Current Rename the Excitation PhaseC1 Enter -750A As the default current direction plotted in red is not good, choose Negative Validate the Excitation


Topic – Motor Application Note Apply Excitations (Cont’d) Switch the selection mode to face Enter Excitation for Coil PhaseB2 1. Select the PhaseB2

2. 3. 4. 5. 6.

Right mouse click, select the menu item Apply Excitation > Current Rename the Excitation PhaseB2 Enter -750A As the default current direction plotted in red is good, leave Positive Validate the Excitation


Topic – Motor Application Note Apply Excitations (Cont’d) Switch the selection mode to face Enter Excitation for Coil PhaseB1 1. Select the PhaseB1

2. 3. 4. 5. 6.

Right mouse click, select the menu item Apply Excitation > Current Rename the Excitation PhaseB1 Enter -750A As the default current direction plotted in red is good, leave Positive Validate the Excitation


Topic – Motor Application Note Inductance computation We are interested by the inductances computation. The source set up is independent from the winding arrangement: we have only entered the corresponding amp-turns for each terminal. When looking at the inductances, we obviously need to enter the number of turns for the coils and also how the coils are electrically organized. Select Parameters in the project tree, right mouse click and select Assign >

Matrix

Include the 6 phases in the matrix computation. The inductances are computed for 1 turn at this stage.

Select the Post Processing tab. We define in this panel the number of turns for each coil. Enter 9 for the six coils. We also want to group all the coils of the same phase. This will enable us to have the inductance of the entire winding Ansoft Maxwell Field Simulator

Topic – Motor Application Note Inductance computation (Cont’d) Select the PhaseA1_in and PhaseA2_in entries, they hit the group button. Name The group PhaseA

Repeat the operation for the 3 phases

Analyse Right mouse click on the setup et select Analyze or click on the


icon.

Topic – Motor Application Note Post processing The computation takes 6 passes to converge. The Convergence panel can be seen by right mouse clicking on Setup1, selecting the menu item Convergence

Inductance values. Select the ‘Solutions’ tab. The inductance for each coils appears. It is assumed that each coil has only one turn.


Topic – Motor Application Note Post processing (Cont’d) Select the radio button Post Processed. The inductance for each winding is displayed

Note: it is possible to export the inductance matrix to Simplorer using the Export Circuit button

Torque value. Select the ‘Solutions’ tab, Select from the pull down menu Torque1. The torque for the full motor needs to be multiplied by 8 (symmetry factor), then multiplied by 0.083 (length of the motor). This gives around 47N.m. In this case, we have not synchronized the position of the rotor poles with the winding currents, so we are far from the optimized excitation value to obtain a maximum torque. Different angles between the rotor and the stator would give different values.


Topic – Motor Application Note Post processing (Cont’d) Plot the H field on the plane XY. Select the plane XY belonging to the global Coordinate System in the modeler tree

Move the mouse pointer to the drawing area, right mouse click and select the menu item Fields > H > H_vector

Validate the setting


Topic – Motor Application Note Post processing (Cont’d) With the default parameters, the H vectors are too small. Double click on the scale zone

On the ‘Color Map’ tab, uncheck the ‘Real time mode’ button and change the number of colors to 50 On the ‘Scale tab’ , Check the Use Limits button, then Enter 1 and 1e6 for the limits. Also, Check the Log button to have a log scale.


Topic – Motor Application Note Post Processing (Cont’d) On the ‘Marker/Arrow’ tab, reduce the size of the arrow, then uncheck the Mapsize and Arrow tail buttons. On the ‘Plots’ tab, make sure the right plot context is selected, then modify the Vector plot min and max to 1 and 5

We obtain the following plot. The H field is stronger around phase A as the input current is higher.



DYNAMIC ANALYSIS We will study the transient characteristic of the motor. Save the project. Click on the Maxwell design ‘2_Partial_motor’, right mouse click and select ‘Copy’.

Click on the project name, right mouse click and select Paste. Change the copied design to ‘5_Partial_motor_TR’. Select the design name from the project manager, Right mouse click and change the solution type from Magnetostatic to Transient:



The transient solver acts differently from the Magnetostatic solver mainly because: There is not adaptive meshing. Since the geometry changes at every time step, Maxwell does not re-mesh at every time step adaptively for obvious time reason. In transient analysis, we will build a good mesh valid for all the rotor positions. The sources definition is different. In Magnetostatic, we were only interested in the total current flowing into conductor. In Transient, we use stranded conductors (the exact number of conductors is required for each winding) as the current can be an arbitrary time function. We need to create dedicated coils and windings.

Create Coils Select the 6 coils PhaseA1, PhaseA2, PhaseB1, PhaseB2, PhaseC1 and PhaseC2. Right mouse click and select the menu item Assign Excitation > Coil 1. Leave the default name as it will be automatically affected using the object’s name 2. Enter 9 for the number of conductors


Topic – Motor Application Note Create Coils (Cont’d) The six coils definitions are processed.

We need to change the orientation of the coils for PhaseC1 and PhaseC2: 1. 2. 3. 4.

Select PhaseC1, in the Project Manager Tree Right mouse click and select Properties Switch the polarity from Positive to Negative Repeat 1-3 with Coil PhaseC2


Topic – Motor Application Note Motor excitation The IPM motor is such that the rotor is in synchronism with the phase excitation. The excitation is such that the flux due to the permanent magnet is maximized in synchronization with the rotor movement. The excitation is a 3 phase balanced current. The phase sequence is A+C-B+ At t=0, the A-phase has to be in the opposite axis to the d-axis. Therefore we have to move the initial position of the rotor by 30 deg such that the pole be aligned at the middle of A+A-

Bd-axis

BC+ C+ AA-

A-

B+ AC+

B+ C+

B-

C- CA+ B- A+

Maxwell model parts

30° Ansoft Maxwell Field Simulator

Topic – Motor Application Note Create Parameters for excitations We need to define parameters that will be used to define the excitation Select the menu item Maxwell 2D> Design Properties The parameters window appears Click on the Add button to add the number of poles of the motor Enter Poles in the name area 8 in the value area Click on OK to accept the parameter

Using the same method enter: PolePair, the number of pair of poles; its value is Poles/2

Speed_rpm, the speed of the motor in rpm; its value is 3000 Omega, the pulsation of the excitation in degrees/s; its value is 360*Speed_rpm*Polepair/60 Omega_rad the pulsation in rad/s; its value is Omega * pi / 180 Thet _deg the load angle of the motor ; for instance, we use 20 degrees in this study; enter 20 deg. Thet is load angle in radian therefore its value is Thet_deg * pi /180 Imax the peak winding current of the motor; its value is 250A.


Topic – Motor Application Note Create Parameters for excitations (Cont’d) The design properties panel will eventually look like:

Create Windings The terminals are meant to define the excitation paths in and out of the model. The actual excitation is defined through the definition of windings. A winding needs to be defined for each parallel electrical excitation of the motor. The motor is excited with a balanced three phase connection. A sinusoidal excitation is applied. At each time step, the phases have a 120 degree shift. The load angle is also added.


Topic – Motor Application Note Create Windings (Cont’d) Winding PhaseA.. From the project tree, right mouse click on Excitations, then select the menu item Add Winding

1. 2. 3.

4. 5.

6.

Enter PhaseA for the name. Select Stranded because each terminal has 9 turns Enter winding current: Imax*sin(Omega_rad*Time+Thet). Time is the internal reserved variable for the current time. Click on OK Right mouse click on the winding PhaseA from the project tree, select the menu item Add Coils

Select the 2 PhaseA coils (using the Ctrl button) and click on OK


Topic – Motor Application Note Create Windings (Cont’d) Winding PhaseB.. From the project tree, right mouse click on Excitations, then select the menu item Add Winding. Repeat the same operation using : Name the Winding PhaseB The winding current is Imax*sin(Omega_rad*Time-2*pi/3+Thet). It is shift by -120 degrees from PhaseA. Select the 2 PhaseB t coils Winding PhaseC.. From the project tree, right mouse click on Excitations, then select the menu item Add Winding. Repeat the same operation using : Name the Winding PhaseC The winding current is Imax*sin(Omega_rad*Time+2*pi/3+Thet). It is shift by +120 degrees from PhaseA. Select the 2 PhaseC coils The project tree should now have the terminals sorted under each Winding:


Topic – Motor Application Note Add Coreloss computation The coreloss are not activated by default. If you wish to have them considered, expand the project tree window, right mouse click on Excitations> Set Core Loss

Select the steel objects: Stator, Rotor, Rotor2 and Rotor3 Accept the Setting

Note: you need to have the coreloss parameters defined in the material setup


Topic – Motor Application Note Add Band object The moving parts (rotor and permanent magnets) need to be enclosed in an air object, the band. This will separated the moving part from the fixed part of the project. Some rules apply for the definition of the band object for motor applications: The band object must be somewhat larger than the rotating parts in all directions (except at the boundaries) The band object should be a facetted type cylinder of wedge It is very advisable to have an air object that encloses all the moving object inside the band object. This will facilitate the mesh handling around the air gap To create the Band object, we will clone the region and adapt the parameters: 1. Select the object Region, Right Mouse click, then Select Edit > Copy

2. 3. 4.

Use the Ctrl+V key combinaison to paste the Region. Change the name of the object from Region1 to Band Expand the history tree of the Object


Topic – Motor Application Note Add Band object (Cont’d) 5.

Double click on the CreateLine command. The rotor radius is 80.2mm. The inner diameter of the stator 80.95mm. We pick the middle for Band object . Enter 80.575,0,0 mm instead of 200,0,0 for Point2

7.

Double Click on the Sweep AroundAxis command. Change the Number of Segments from 5 to 45 so that each segment of the line covers one degree

8.

Leave the material to Vacuum.

6.


Topic – Motor Application Note Add Band object (Cont’d) We now create an object that enclosed the moving objects inside the Band. Select the Band object, right mouse click, the select the menu item Edit > Copy or use Ctrl-C. Paste another copy of the Band object by right mouse clicking and selecting Edit > Paste or with the Ctrl-V. A new object Band1 has been added to the object list. Expand its history tree, then double click on the CreateLine command

Edit the Point2: Enter 80.4, 0, 0 mm This operation resizes the object to strictly cover the rotor and the permanent magnets Rename the Band1 object to Band_in

Note: We will assign the motion after the mesh operations because we will have to add objects dedicated to the meshing in the moving part


Topic – Motor Application Note Mesh Operations The transient solver does not use adaptive meshing because this would require to refine the mesh at every time steps, leading to very high computation time. Using Mesh operations, we will define a decent mesh for the full transient simulation. The Rotor is designed to be highly saturated around the permanent magnets, close to the air gap. It is required to have a good mesh density around this area.

Highly saturated zones

To achieve this requirement, we create a couple of objects inside the rotor, then mesh operations will be applied to these objects in order to have a nice mesh around the ducts. Select the menu item Draw > Line or select the icon from the toolbar. 1. Enter 78.72,0 ,0 mm for the position of Point1 and hit Enter 2. Enter 80.2,0 ,0 mm for the position of Point2 and hit Enter twice 3. Name the line Rotor2


Topic – Motor Application Note Mesh Operations (Cont’d) The line looks like below:

Select the Rotor2 object, right mouse click and select the menu item Edit >

Sweep > Around Axis. Enter the parameters as below. Note that The Rotor object has been created with an UDP which produces true surface, therefore our mesh object Rotor2 has to have true surfaces. As a consequence, we enter 0 for the number of segments.


Topic – Motor Application Note Mesh Operations (Cont’d) Change the material property of Rotor2 to M19_29G. Also, assign some color and transparency. Note: since Rotor2 is entirely inside Rotor, we do not need to apply Boolean operations. Note: because of the finite number of pixels on the computer’s screen, true surfaces are represented as facetted surfaces. Also, for the same reason, the object Rotor2 seems to intersect with the ducts but this is not the case. You can modify the default visualization setting using: View > Visualization Setting

Repeat the same operation to create the object Rotor3: 1. Draw a line with dimensions:

2. 3.

Sweep the rectangle around Z axis Change the material property to M19_29G


Topic – Motor Application Note Mesh Operations (Cont’d) Select the six coils PhaseA1, PhaseA2, PhaseB1,PhaseB2, PhaseC1 and PhaseC2. Right mouse click, select Assign Mesh Operations > Inside Selection > Length Based. 1. Name the operation Coils 2. Check the button Restrict Length of Elements 3. Enter 4mm 4. Uncheck the button Restrict the Number of Elements 5. Validate

Select the permanent magnets PM1 and PM2. Right mouse click, select Assign Mesh Operations > Inside Selection > Length Based. 1. Name the operation PMs 2. Check the button Restrict Length of Elements 3. Enter 3mm 4. Uncheck the button Restrict the Number of Elements 5. Validate


Topic – Motor Application Note Mesh Operations (Cont’d)

Select the Rotor. Right mouse click, select Assign Mesh Operations > Inside Selection > Length Based. 1. Name the operation Rotor 2. Check the button Restrict Length of Elements 3. Enter 4mm 4. Uncheck the button Restrict the Number of Elements 5. Validate

Select the Stator. Right mouse click, select Assign Mesh Operations > Inside Selection > Length Based. 1. Name the operation Staor 2. Check the button Restrict Length of Elements 3. Enter 4mm 4. Uncheck the button Restrict the Number of Elements 5. Validate


Topic – Motor Application Note Assign Movement Select the Band object, right mouse click and select the menu item Assign Band

In the Type tab: check the Rotate motion button Make sure that the Global:Z axis is selected Select the Positive direction In the Data tab: Enter 30 deg for the initial position. The initial position of this synchronous motor is such that the A phase is opposite to the daxis. d-axis 30° A-

A+


Topic – Motor Application Note Assign Movement (Cont’d) In the Mechanical tab: enter 3000 rpm for the speed. Click OK to validate the setting of the Band object. Right mouse click on Model in the Project tree, then select the menu item Set

Symmetry Multiplier

Since we model 1/8th of the motor (our model spans on 45°), Enter 8. The force, torque will be rescaled to take into account the full model.

Select the Model Depth tab. Enter 83.82mm for the motor depth. All quantities will be automatically be rescaled to the correct size. Accept the setting


Topic – Motor Application Note Add an Analysis Setup Right mouse click on Analysis in the Project tree and select Add Solution Setup: 1. On the General tab enter the stop time and the time step. At 3000 rpm, a revolution takes 20ms (3000 rpm means 50 revolutions per second or 1/50 s for one revolution) . To achieve reasonable accuracy, we want to have a time step every 1 or 2 degrees. In this study, to have faster results, we use a time step of 250 us; it corresponds to 4.5 degrees. 2. The total simulation time is set to 15ms 3. On the Save Fields tab Select Linear Step For Start, put 10ms For Stop, put 15ms For Step Time, put 250us Click on Replace List 4. In the Solver Tab, set the Non linear residual to 1e-6.


Topic – Motor Application Note Solve the problem The setup is completed. Check the project using the Validate button

Maxwell checks the geometry, excitation definitions, mesh operations and so one. The model is validated but some Warning is displayed in the message box: Eddy effect are not taken into account in our design which is what we decided

Select the Analysis Setup1 in the project tree, right mouse click and select

Analyse


Topic – Motor Application Note Post Processing The full simulation takes some minutes. The mesh size appears in the profile of simulation. To display the profile, select the Analysis Setup, right mouse click and select Mesh Statistics. The mesh statistics are available in the corresponding tab Performance curves can be displayed during the simulation.

Torque versus Time. Select the menu item Results in the project tree, right mouse click, then select the menu item Create Quick Report

Choose Torque The Torque up to the current time is displayed. As the simulation continues, you can update the plots: right mouse click on the Torque Quick Report entry and select Update Report


Topic – Motor Application Note Post Processing (Cont’d)

At the end of the simulation the Torque looks like below Torque Quick Report1

Ansoft Corporation

5_Partial_Motor_TR

300.00

250.00

Y1 [NewtonMeter]

200.00

Curve Info

150.00

Moving1.LoadTorque Setup1 : Transient Moving1.Torque Setup1 : Transient

100.00

50.00

0.00

0.00

5.00

10.00 Time [ms]

15.00

20.00

The LoadTorque (in red) is zero as we are in motor mode. We can see that there are a lot of ripples in the Torque. The ratio between the torque and the torque ripples is almost 10 percent. This is due to the unique structure of the IPM motor (Internal Permanent Magnets). To limit the ripple, some manufacturers modify slightly the rotor shape around the magnets or add a second layer of internal magnets. Also the control strategy plays a big role into preventing the ripples. The torque value is around 240 N.m. This value is compatible with measurement. The peak torque for this motor is about 400 N.m

Flux linkage versus Time. Select the menu item Results in the project tree, right mouse click, then select the menu item Create TransientReport > Rectangular Plot.


Topic – Motor Application Note Post Processing (Cont’d)

To include the flux linkage for each coil: 1. Select Winding in the Category Column 2. Select FluxLinkage(PhaseA), FluxLinkage(PhaseB), FluxLinkage(PhaseC) in the Quantity column 3. Select New Report 4. Select Close

XY Plot 2

Ansoft Corporation

5_Partial_Motor_TR

0.40

Curve Info FluxLinkage(PhaseA) Setup1 : Transient

0.30

FluxLinkage(PhaseB) Setup1 : Transient

0.20

FluxLinkage(PhaseC) Setup1 : Transient

Y1 [Wb]

0.10 0.00 -0.10 -0.20 -0.30 -0.40

0.00


5.00

Time [ms]

10.00

15.00

Topic – Motor Application Note Post Processing (Cont’d) Induce Voltage versus Time. Select the menu item Results in the project tree, right mouse click, then select the menu item Create TransientReport > Rectangular Plot. Use the same method to plot the Induced Voltage

XY Plot 1

Ansoft Corporation

5_Partial_Motor_TR

500.00

Curve Info

400.00

InducedVoltage(PhaseA) Setup1 : Transient

300.00

InducedVoltage(PhaseB) Setup1 : Transient

200.00


Y1 [V]

100.00 0.00 -100.00 -200.00 -300.00 -400.00 -500.00

0.00

5.00

10.00

Time [ms]

15.00

The curves are not really smooth. The reason is that the time step is too high. As the induced voltage is a derived quantity, Maxwell needs to derive the total flux ; the time steps is way to high to have accurate Induced Voltage. If you re run the simulation with a time steps of 50us (instead of 250 us), the Induced Voltage will have a more realistic shape: XY Plot 1

Ansoft Corporation

5_Partial_Motor_TR_small

500.00

Curve Info

400.00

InducedVoltage(PhaseA) Setup1 : Transient

300.00

InducedVoltage(PhaseB) Setup1 : Transient

200.00


Y1 [V]

100.00 0.00 -100.00 -200.00 -300.00 -400.00 -500.00


0.00

5.00

Time [ms]

10.00

15.00

Topic – Motor Application Note Post Processing (Cont’d) Plot the Mesh. Select all the object, right mouse click and use the Plot Mesh button

Plot magnetic flux density. 1. Select the menu item View > Set Solution Context or double click on the “Time=-1” icon in the modeler window

2.

Select the time 0.01s from the pull down menu



4. 5. 6.

7. 8.

Select the Stator, Stator2, Stator3, PM1 and PM2 objects. Right mouse click and select Fields > B > Mag B Accept the Setting The B field at 0.01s is displayed. Change the scale by double clicking on the Scale aera

Go to the Scale Tab and enter 0 for min and 2.2 for max Close the Window


Topic – Motor Application Note Post Processing (Cont’d) Plot magnetic flux density (Animation). It is possible to animate the fields. Select Maxwell2D > Fields > Animate. Make sure that the sweep variable is Time Select the time values Accept the setting

The animation is displayed once the frames are calculated. You can export the animation using the Export button from the animation button


Topic – Motor Application Note Parametric Study The setup that has been solved was with a load angle of 20 deg. If the load angle is modified, the simulation has to be restarted. A parametric sweep of the load angle will therefore take a long time. We can propose two approaches: Realize an Equivalent Circuit Extraction of the motor. This method requires the combination of parametric sweeps in magneto-static and the circuit simulator Simplorer. We will not discuss this method in this write-up. Realize a parametric transient simulation. To cut the simulation time, the use of the Distributive Solve is necessary. This is the chosen method

Click on Optimetrics in the Project tree. Right mouse click and select the menu item Add > Parametric

The parametric setup panel appears


Topic – Motor Application Note Parametric Study (Cont’d) Select the Add button to include a design variable in the sweep

Select Thet_deg from the pull-down menu: 1. Enter 0 deg for the first value 2. Enter 60 deg for the last value 3. Enter 15 deg for the step 4. Push the Add button Select the ‘Table’ tab, the parametric rows are displayed


Topic – Motor Application Note Parametric Study (Cont’d) Select the General’ Tab. This panel enables the user to change a design variable. For instance, if you wish to run the parametric sweep with a peak winding current of 400 A, select the Override button, and change the current value.

Select the Calculations Tab 1. Select the Setup Calculations button 2. Under the Category column, select Torque 3. Under the Quantity column, select Moving1.Torque 4. select the Range Function button. 5. Select the Specified radio button 6. Setect the Math Category 7. Select avg in the Function pull down menu 8. Click on ok 9. Click on Add Calculation 10. Click on Done


Topic – Motor Application Note Parametric Study (Cont’d) The sweep setup panel contains the desired quantity

In the Options tab, you can choose to save fields and meshs for all the variations Accept the setup Run the parametric sweep. To run the sweep, select the Parametricsetup1, right mouse click and select the menu item Analyse Results. Right mouse click on Parametricsetup1, and select View Analysis Result

All the plots are now available for any variation



COGGING TORQUE The Cogging Torque corresponds to the torque due to the shape of the teeth and the permanent magnets, when all the coils excitations are 0. The torque is a very small value in regard to the full load torque. Its computation is very sensitive to the mesh, as its value is in the same order of magnitude of the mesh noise. To compute accurately the cogging Torque, one could solve a parametric sweep in Magnetostatic (the input parameter being the angle between rotor and stator). This method will not lead to excellent results as the error due to the mesh will be different for each position (the mesh will change for every row). The preferred method is the use of the transient solver with motion: We will move the rotor at the speed of 1 deg/s The mesh will remain unchanged for all the positions thanks to the Band object : the mesh inside the Band object will rotate with the rotor Each time step will be independent of the other The adaptive mesh will not be used therefore the simulation time will be shorter Save the project. Click on the Maxwell design ‘5_Partial_motor_TR’ , right mouse click and select ‘Copy’. Click on the project name, right mouse click and select Paste. Change the copied design to ‘6_Partial_motor_CT


Topic – Motor Application Note Creation of an air Object We derive the set up for the cogging torque calculation from the Full load setup. We will change the speed, the excitations and some meshing operations. Since the mesh has to be well defined in the air gap, we will add an object so that we have enough layers of element: 1. Copy and Paste the Object Band_in 2. Rename the object Band_in1 into Band_out.

3.

Expand the history tree of Band_out and change the CreateLine command: Replace 80.4 ,0 ,0 by 80.75 ,0 ,0 mm

This create a third layer in the air gap

Stator Band_out Band Band_in Rotor2 Rotor3 Rotor


Topic – Motor Application Note Increase the segmentation of air objects

For the dynamic analysis, the ojects Band, Band_in had one segment every degre. In order to reduce mesh error, we reduce the span of each segment. Expand the history tree of the objects Band, Band_in and Band_out: 1. Double click on the SweepAroundAxis command of the Band object

2. 3.

Change the number of segments from 45 to 135 Repeat 1-2 for the objects Band_in, Band_out


Topic – Motor Application Note Meshing Operations We need to reassign the Band. Expand the project tree of the current design, and delete the MotionSetup1

Select the Object Band, right mouse click, and select Assign Band

Enter the following parameters for the Motion Setup In the Type Tab, for Motion Type: Rotation around Z axis Leave the Data tab unchanged In the Mechanical tab, enter 1 deg_per_sec Accept the Setting


Topic – Motor Application Note Meshing Operations We also need to change the meshing operations. The mesh density that was good enough to compute the full load torque won’t be accurate enough for the cogging torque Expand the project tree, and under Mesh operations, edit the Meshing operations Rotor, Stator: Change the maximum length from 4mm to 3mm

Select the objects Rotor, Rotor2, Rotor3 and Stator. Right mouse click and select Assign Mesh Operation > Surface Approximation Name the meshing operation SA_Rotor_Stator Set the minimum normal deviation to 1 deg Ignore the other settings


Topic – Motor Application Note Create the Analysis Setup We can delete the coils as they are not needed in the cogging torque simulation Select the 6 coils and delete them

Expand the analysis setup already defined and edit it: One pole pair takes 7.5 mech degrees. We will solve over 15 s in order to have two periods (remember: the speed is 1 deg/s) We set the time step to 0.125 s to have a very smooth curve. An higher time step is still valid if you want a faster result. Lower the non linear residual to 1e-4. Accept the Setting


Topic – Motor Application Note Analyse From the project tree, right mouse click on Setup1, and select Analyse. It takes a couple of minutes to solve From the project tree, right mouse click on Results, and select Create Transient Report > Rectangular plot. The Trace window pops up From the Category column select Torque From the Quantity column, select Moving1.Torque Select New Report Select Close

The Torque trace appears. As expected, the cogging torque is periodical. The peak value is about 1.75 N.m. Cogging Torque

Ansoft Corporation

6_Partial_Motor_CT

2.00



1.50 1.00 0.50 0.00 -0.50 -1.00 -1.50 -2.00

0.00


5.00

Time [s]

10.00

15.00

Ansoft Maxwell v12 2D User Guide-Machine Design Reference Guide

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