A short insight to governing of steam turbines.This will be more useful and mean more to Power Plant professionals and for those who are beginners or trainees in the Thermal Power Plants.Descrição completa
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kwu steam turbineFull description
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Governing Through the Brain - Nikolas Rose
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Governing Through the Brain - Nikolas Rose
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Descrição: Here is a list of multi phase solvers of openFoam with the governing equations
Here is a list of multi phase solvers of openFoam with the governing equations
technical directive of power plant
Whilst there is currently much guidance available on how to manage marine protected areas (MPAs), there is less guidance available that considers MPAs from a governance perspective. This perspectiv...
Quality of power depends on: Frequency
Voltage
These need to be regulated properly for stable and accurate output for good performance. Governing system is used for regulating frequency and power output.
Quality of power depends on: Frequency
Voltage
These need to be regulated properly for stable and accurate output for good performance. Governing system is used for regulating frequency and power output.
Hydraulic turbine governor is used for controlling the guide vanes by detecting turbine speed & its guide vane opening in order to keep turbine speed stable or to regulate its output.
The
performance
dominates
the
of
the
controllability
governor of
the
power plant and quality of an electrical power produced .
Speed Signal
Electrical/Electronic Governor
Hydro-Mechanical Cabinet
G.V.Position Feedback Device
Oil Pressure Unit
Servomotors
TYPE
PMG
Toothed Wheel (capacitor type probe)
PT Voltage (frequency detection)
Over Speed Detection (mechanical)
Governor is a speed sensing type,sensitive to speed deviation from a set value of speed.The speed signal is generally produced with a turbine shaft mounted toothed wheel and magnetic pickup. f = n * p / 60,
f = frequency of sensor output
n = speed of the toothed wheel( r.p.m)
p = no. of teeth on the toothed wheel
The signal is processed in frequency to voltage converter
Speed Control
Power Control
Braking
Field Breaker Control
Over Speed Tripping
Machine Standstill Signal
To Servo Motor Displacement of Transducer
Supply
W
W
C
W
LVDT – Linear Voltage Differential Transducer
FEEDBACK MECHANISM
POWER SUPPLY UNIT SPEED SIGNAL MODULE SPEED RELAYS SPEED SETTING POWER SETTING PERMANENT SPEED DROOP TEMPORARY SPEED DROOP AMPLIFIERS
Freq. Signal Freq. Ref. Setting O/P Setting Command
Comparator
-
P. Droop Setting
Permanent Droop Signal Summation Amplifier
Booster Amplifier
E. Hydro. Transducer Gate Opening Feedback
From OPU Hydro. Amplifier
Servo Motor
PERMANENT DROOP
100%
100%
r e w o P
r e w o P
0 45 HZ
Freq.
50 HZ
Permanent Droop Setting 10%
0 47.5 HZ
Freq.
50 HZ
Permanent Droop Setting 5%
TEMPORARY DROOP SIGNAL Freq. Signal Freq. Ref. Setting O/P Setting Command
Comparator
-
Differentiator Adjustable Setting of Time & %
Temp. Droop Signal
Summation Amplifier
Gate Opening Feedback
Temporary Droop Signal is a damping signal. It opposes transiently gate movement and thus provides main stablisation to speed control loop.
Prevents Governor action over a selected band of speed
M/c will maintain constant power for system frequency variation of (Fn
It is to disengage the generator brakes when turbine comes to almost dead halt
It gives signal when speed drops out to less than 0.1 Hz
GOVERNOR PANEL FOR CONTROL OF SPEED AND POWER OF THE MACHINE
STATUS COMMAND COMMAND START STOP SPEED SIGNAL C.B. POSITION (M/C) (M/C) (PMG.SSG.PT.)
GATE POSITION FEED BACK
GOVERNOR
O U T P U T
SPEED SETTING OUTPUT GATE COMMAND SETTING OPEN LIMIT POSITION COMMAND COMMAND
GOVERNOR
INDICATION FOR 1 2 3 4 5
SPEED GATE POSITION SPEED SETTING OUTPUT SETTING EHT CURRENT
GATE OPEN/CLOSE CONTROL SENSING OF SPEED RELAYS 1 2 3 4 5
ZERO SPEED BRAKE PROTECTION EXCITATION CONTROL H.S.LUB.START
Commands
GOVERNING SYSTEM Gate Servomotor
Temp. Droop Amplifier Permanent Droop
Distributing Valve
Gate Or Needle
Turbine Speed/Freq. Sensor Gen. PT Voltage
PMG/ TWG
GATE POSITION SWITCH (MASTER CONTROLLER) 1. Gate Closed Position 2. M/C Start Gate Open Position 3. Controlled Action Shutdown Gate Position 4. Full Gate Open Position
CONTROL AVAILABLE IN GOVERNOR 1. Auto/Mannual Selector Switch 2. Local / Remote Selector Switch 3. Increase/Decrease Power/Frequency These Buttons/Switch Changes
5. Droop Characteristic One of two Permanent Droop curves may be selected. However set values of curves has to be altered by software package
AUTO/MANUAL SWITCH
GATE POSITION LIMITER
GUIDE VANE POSITION INDICATOR
SPEED INDICATOR
BALANCE INDICATOR
PRESSURE INDICATOR
ELECTRO HYDRAULIC TRANSDUCER
EMERGENCY SLIDE VALVE
GUIDE VANE OPENING FEEDBACK
SPEED CONTROL BY SERVOMECHANISM
SPEED SIGNAL GENERAROR
SPEED SENSOR
MECH. CONNECTION
ELECT. GOV
GENERATOR PILOT SERVO VALVE
TURBINE
TURBINE INFLOW
TURBINE WICKWT GATE
HYDRAULIC POWER
TURBINE SERVOMOT0R
MAIN VALVE
RETURN OIL/LEAKAGE PRESSURE TANK 40
Kg/CM2
OIL PUM P
OIL SUMP
G.V. Opening
Limiter
Start Pos. 1 Start Pos. 2 No Load Position G. V. Lock to Service Position
Time Start Input
1.
Unit acceleration time (Tm) This is the time in seconds to accelerate the unit from standstill to normal speed. It is a measure of sensibility of the unit on load changes. Given by: Tm = WR2n2 /(9.08*104*N) WR2= flywheel effect of generation in kg-m2 n= Rotational speed N= Turbine capacity in kW
2.
Inertia of water mass (TW) Higher inertia of water masses leads to unstable governing. Where the water conductor system is long, Surge tanks are provided. Given by, TW= ∑ LV/(g*h) Where, L= length of water conductor in m V= velocity in m/sec. H= Rated head in m
3.
SPEED RISE: Depends upon guide vanes/ Deflector minimum closing time.
MACHINE IS TRIPPED FOR VERY LOW PRESSURE AND VERY LOW LEVEL AND FOR LOW LEVEL/PRESSURE ALARM IS PROVIDED
RECEIVER SWITCH,
LEVEL RELAY
OIL SUMP TANK
MOTOR STARTER
OIL PUMPS
PRESSURE RELAY
PRESSURE RECEIVER
LEVEL RELAY
HP COMPRESSED AIR
ELECT. HYDRAULIC GOVERNOR
OLU
G. V. SERVOMOTOR
OIL PUMPING UNIT
GUIDE VANES
Pump Motors are controlled in Auto Mode by the following Pressure switches: Pressure Normal Stop both pumps Pressure switch to start pump – main Pressure switches for M/c control Pressure Normal – Unit ready to start condition Pressure Low - Alarm - Emergency shut Pressure Very Low down
Sump oil level normal
Sump oil level low
Pressure receiver oil level normal
Pressure receiver oil level low (Pumps are not working)
Pressure Receiver oil level high (Air admission is required)
