Delayed Current Zero Crossing Characteristics for Circuit Breaker Interrupting Short-Circuit Current Following Permanent Single-phase Ground Fault on Short 1000kV AC Lines

摘要

For double or multiple circuits of 1000kV lines on the same tower, where a permanent single-phase ground fault occurs on one circuit, delayed current zero crossing may take place during single-phase reclosing of circuit breaker. This may overburden and even damage the breaker. This paper uses the ATP-EMTP program to simulate various operating conditions of a 1000kV system with varying grid configuration, line length, number of circuits, time of single-phase reclosing and location of fault, and proposes the probability of occurrence of delayed current zero crossing accordingly.