Page 1 Capacitor and Reactor Switching, J. H. Brunke, July 2008 Presented at IEEE Circuit Breaker Tutorial Application of Power Circuit Breakers for Switching Capacitive and Light Inductive Currents IEEE Circuit Breaker Tutorial Dr. John H. Brunke, P.E. Fellow
51
Embed
Switching Capacitive and Light Inductive Currents€¦ · switching shunt capacitor banks, shunt reactors, transformers, cables, and lines (capacitive and light reactive currents).
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Page 1 Capacitor and Reactor Switching, J. H. Brunke, July 2008 Presented at IEEE Circuit Breaker Tutorial
Application of Power Circuit Breakers for Switching Capacitive and Light Inductive
CurrentsIEEE Circuit Breaker Tutorial
Dr. John H. Brunke, P.E.Fellow
Page 2 Capacitor and Reactor Switching, J. H. Brunke, July 2008 Presented at IEEE Circuit Breaker Tutorial
Nature of Capacitive and Small Inductive Currents
Small in magnitudeSome technologies use current to assist in interruption
Current and voltage 90 degrees out of phaseCircuit breakers frequently called upon to deal with switching these
currentsSwitching can result in extreme magnitudes of currents and extreme
rates of change of voltage
This presentation is based on C37.012 and C37.015, the application guides for switching these currents. It is impossible to cover all the material in these in detail, and there are other important issues with switching these currents that are not covered in the application guides. This presentation is intended to provide an overview of all the issues associated with switching these currents.
Page 3 Capacitor and Reactor Switching, J. H. Brunke, July 2008 Presented at IEEE Circuit Breaker Tutorial
Shunt Capacitor Bank SwitchingContinuous Current
Margins for capacitor toleranceMargins for harmonic currentMargin of 35% typical
Interrupting shunt capacitor bank current
Page 4 Capacitor and Reactor Switching, J. H. Brunke, July 2008 Presented at IEEE Circuit Breaker Tutorial
What is a Restrike?
Page 5 Capacitor and Reactor Switching, J. H. Brunke, July 2008 Presented at IEEE Circuit Breaker Tutorial
Restrike, Back to Back with CLR’s
Page 6 Capacitor and Reactor Switching, J. H. Brunke, July 2008 Presented at IEEE Circuit Breaker Tutorial
Energizing Shunt Capacitor Banks
Single or isolated bank
Back to back
Page 7 Capacitor and Reactor Switching, J. H. Brunke, July 2008 Presented at IEEE Circuit Breaker Tutorial
500 kV Single Bank Energization
Page 8 Capacitor and Reactor Switching, J. H. Brunke, July 2008 Presented at IEEE Circuit Breaker Tutorial
500 kV Back to Back Energization
Page 9 Capacitor and Reactor Switching, J. H. Brunke, July 2008 Presented at IEEE Circuit Breaker Tutorial
Consequences of Capacitor Inrush Transients
Dip to zero voltageInterference with devices that use zero crossing detectors
Back to back results in extremely high currentsDamage to primary and secondary equipmentSafety
Restrike (trapped charge)2 X the voltage, effects 2 X
Page 10 Capacitor and Reactor Switching, J. H. Brunke, July 2008 Presented at IEEE Circuit Breaker Tutorial
Mitigation of Closing TransientsClosing Resistor or Reactor
Fixed Current Limiting Reactor
Controlled closing
Page 11 Capacitor and Reactor Switching, J. H. Brunke, July 2008 Presented at IEEE Circuit Breaker Tutorial
500 kV Back to Back Energization with CLR
Page 12 Capacitor and Reactor Switching, J. H. Brunke, July 2008 Presented at IEEE Circuit Breaker Tutorial
Controlled Closing, Single Bank
Page 13 Capacitor and Reactor Switching, J. H. Brunke, July 2008 Presented at IEEE Circuit Breaker Tutorial
Controlled Closing, Back to Back
Page 14 Capacitor and Reactor Switching, J. H. Brunke, July 2008 Presented at IEEE Circuit Breaker Tutorial
Controlled Closing, Capacitor Banks, targeting
Page 15 Capacitor and Reactor Switching, J. H. Brunke, July 2008 Presented at IEEE Circuit Breaker Tutorial
Switching Capacitor Through a Transformer
Page 16 Capacitor and Reactor Switching, J. H. Brunke, July 2008 Presented at IEEE Circuit Breaker Tutorial
Faults Near Capacitor Banks
•Outrush, TRV effects, high source impedance voltage rises (or long lining), etc.
Page 17 Capacitor and Reactor Switching, J. H. Brunke, July 2008 Presented at IEEE Circuit Breaker Tutorial
Line Fault, 500 kV system, with 430 Mvar of Connected Capacitors
Page 18 Capacitor and Reactor Switching, J. H. Brunke, July 2008 Presented at IEEE Circuit Breaker Tutorial
Circuit Breaker StandardsRestrike probability: C0, no rating, C1, ~ 1 restrike in 50 operations, C2, ~ 1 restrike in 300 operations
Page 19 Capacitor and Reactor Switching, J. H. Brunke, July 2008 Presented at IEEE Circuit Breaker Tutorial
Circuit Breaker Standards
Page 20 Capacitor and Reactor Switching, J. H. Brunke, July 2008 Presented at IEEE Circuit Breaker Tutorial
Page 49 Capacitor and Reactor Switching, J. H. Brunke, July 2008 Presented at IEEE Circuit Breaker Tutorial
Test on Laboratory Transformer
Page 50 Capacitor and Reactor Switching, J. H. Brunke, July 2008 Presented at IEEE Circuit Breaker Tutorial
Controlled Closing on 500 kV Transformer
Page 51 Capacitor and Reactor Switching, J. H. Brunke, July 2008 Presented at IEEE Circuit Breaker Tutorial
SummaryCapacitive and light reactive currents are frequently seen and may be
the most difficult duties for a circuit breakerSwitching surge/transient problems are typically associated with
switching shunt capacitor banks, shunt reactors, transformers, cables, and lines (capacitive and light reactive currents).
Due to the complexity, correct application for these duties can be among the most difficult application issuesToday solutions are available which were not in the past (modern circuit