Mitigation of circuit breaker transient recovery voltages associated with current limiting reactors

Abstract

B.C. Hydro and Hydro-Quebec utilize current limiting reactors on medium voltage distribution feeders to limit the magnitude of fault current. The reactors make a significant contribution to the severity of the transient recovery voltage experienced by feeder and bus circuit breakers on clearing feeder faults. Based on the conclusions of an investigation of actual circuit breaker failures while performing this duty, the mitigation of the transient recovery voltage associated with the reactors is described.

Semiconductor Devices in Solid-State/Hybrid Circuit Breakers: Current Status and Future Trends

“…When a fault occurs, T 1 , T 2 on and T 3 , T 4 off, the inductor changes from DC mode to AC mode, therefore the fault current could be reduced. To limit fault currents, a series-connected inductor is more effective [29] than a paralleled capacitor. If an inductor is added without assistance of semiconductor switches, the impedance of the inductor may cause considerable phase shifts and voltage drops, which results in bad voltage regulation and higher system losses.…”

Novel current-limiting strategy for solid-state circuit breakers (SSCB) without additional impedance

“…inductors [6], PTC resistors [7] or superconductors [8]. The principle and further theoretical analysis is shown.…”

Transient recovery voltage requirements associated with the application of current-limiting series reactors

“…Ref. [2] provides information on actual circuit breaker failures caused by excessive TRVs and describes mitigation techniques used to avoid such failures for series reactor-limited faults. Refs.…”