Fault Waveform Analysis from Different CTs for Fault Location

This paper investigates a typical 220kV GIS circuit breaker re-ignition fault in practical systems. All types of protection, such as transmission line protection, circuit break failure protection, bus-bar protection and transform protection, coordinate in one fault case. The protection behavior is analyzed. By reproducing the fault process, the coordination among line protections, circuit break failure protections, bus bar protections and transformer neutral point gap protections are studied. The evidence for protection configurations and settings is provided. According to the comparisons between the fault data from the fault recorder and from the busbar protection device, the bus bar differential current is calculated. Analysis result from different current transformers (CTs) verified the fault locations.