Source: Lakervi & Holmes The substation Olof Samuelsson
Outline The substation Substation equipment Overhead lines Lund University / LTH / MIE / Industrial Electrical Engineering and Automation Substation 2
From generator to customer Generation Transmission Distribution Consumption Source: vattenfall.se Östra mottagningsstationen, Lund At the city limit 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 Bus bars, circuit breakers, disconnectors Monitoring point for control center Potential and current transformers Fuses and other protection Lund University / LTH / MIE / Industrial Electrical Engineering and Automation Substation 4
Substation equipment symbols ENGLISH Busbar Generator Two-wdg wdg transformer Line Circuit breaker Disconnector Surge arrester Current transformer Potential transformer SVENSKA Samlingsskena Transformator Ledning Effektbrytare Frånskiljare Ventilavledare Strömtransformator Spänningstransformator 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 Sweden USA Source e:abb Open Closed 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 Combines breaker and disconnector More reliable and compact Lindome 400 kv station Lund University / LTH / MIE / Industrial Electrical Engineering and Automation Substation 9
Current transformer Reduces current Typically 1000/2 A Current monitored Control center Protection equipment P, Q transducers B Source:ABB Lund University / LTH / MIE / Industrial Electrical Engineering and Automation Substation 10
Voltage/potential transformer Sou urce:abb Reduces voltage Typically x kv/110 V Voltage monitored Control center Protection equipment P, Q transducers Also C voltage dividerid Lund University / LTH / MIE / Industrial Electrical Engineering and Automation Substation 11
Surge / lightning arrester Overvoltage trap Alternative to air gap Nonlinear resistance Short-circuits high voltages to ground Source: ABB Lund University / LTH / MIE / Industrial Electrical Engineering and Automation Substation 12
GIS - Gas Isolated Switchgear SF 6 Air Source: Lakervi SF6 gas g Isolates much better than air - reduces size Greenhouse gas Lund University / LTH / MIE / Industrial Electrical Engineering and Automation Substation 13
Transmission towers Source : Nicklasson 400 kv 750 kv Lund University / LTH / MIE / Industrial Electrical Engineering and Automation Substation 14
Insulator disks Voltage level Source:Glover & Sarma Flashover distance Number of disks Air humidity Lund University / LTH / MIE / Industrial Electrical Engineering and Automation Substation 15
Effects of short-circuit current Vibration due to magnetic forces 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 Substation 16