The subs su bsta tati tion on s e m l o & i v r e k a L : e c r u o S
Olof Samuelsson
Outline
• • Substation equipment • Overhead lines
Lund University / LTH / MIE / Industrial Electrical Engineering and Automation
Substation
2
From generator to customer
Generation | | Distribution Consumption
Source: vattenfall.se
Östra mottagningsstationen, Lund
Lund University / LTH / MIE / Industrial Electrical Engineering and Automation
Substation
3
Substation functions • Voltage transformation (reduction) – Power transformer • Connection point for local networks • Switchyard for network configuration – , , • Monitoring point for control center – Potential and current transformers • Fuses and other protection
Lund University / LTH / MIE / Industrial Electrical Engineering and Automation
Lund University / LTH / MIE / Industrial Electrical Engineering and Automation
Substation
5
Layout
Lund University / LTH / MIE / Industrial Electrical Engineering and Automation
Substation
6
Circuit breaker we en
B B A : c r u o S
• Interrupts large current – Several kA – Short-circuit current – Hidden contacts • Control – Protection systems – Manual remote • Design challenge – Speed and current
Lund University / LTH / MIE / Industrial Electrical Engineering and Automation
Substation
7
Disconnector / Isolator • Interrupts small current – Load current • Visible interruption • Manual control or motorized • Design challenge: Weather
Sweden USA Open Closed
Open
Closed
Source: Nicklasson
Lund University / LTH / MIE / Industrial Electrical Engineering and Automation
Substation
8
Disconnecting circuit breaker • More reliable and compact
Lindome 400 kV station Lund University / LTH / MIE / Industrial Electrical Engineering and Automation
Substation
9
Current transformer • Reduces current – • Current monitored – Control center – Protection equipment – P, Q transducers
B B A : e c r u o S
Lund University / LTH / MIE / Industrial Electrical Engineering and Automation
Substation
10
Voltage/potential transformer
B B A : e c r o S
• Reduces voltage – Typically x kV/110 V • Voltage monitored – Control center – Protection equipment – P, Q transducers • so vo age v er
Lund University / LTH / MIE / Industrial Electrical Engineering and Automation
Substation
11
Surge / lightning arrester
• vervo age rap • Alternative to air gap • Short-circuits high volta es to round
Source: ABB
Lund University / LTH / MIE / Industrial Electrical Engineering and Automation
Substation
12
GIS - Gas Isolated Switchgear SF6
Air
Source: Lakervi
• SF6 as – Isolates much better than air - reduces size – Greenhouse gas Lund University / LTH / MIE / Industrial Electrical Engineering and Automation
Substation
13
Transmission towers
n o s s a l k c i N : e c r u o S
Lund University / LTH / MIE / Industrial Electrical Engineering and Automation
Substation
14
Insulator disks
Voltage level Source:Glover & Sarma
Flashover distance
Number of disk
Air humidit Lund University / LTH / MIE / Industrial Electrical Engineering and Automation
Substation
15
Effects of short-circuit current • – Parallel conductors are attracted (F=B·i·l) • Arc – Compare with welding • Heating from current and arc – Fire and explosion • See http://205.243.100.155/frames/longarc.htm
Lund University / LTH / MIE / Industrial Electrical Engineering and Automation
