Application of Dynamic Resistance Measurement in the Contact Ablation Assessment of High Voltage SF6 Circuit Breaker

Abstract

High voltage circuit breakers are most important protective device in power system. The contact ablation may cause the failure of circuit breaker and endangers the safety of the power system. Dynamic resistance measurement (DRM) is considered to be an effective assessment technique for contact ablation when the circuit breaker has a lower breaking speed. However, the resistance curve at higher rated speed during opening operation of high voltage circuit breaker is hardly to identify the main contact part as well as the arcing contact part. In this paper, a DRM characteristic analyzer has been used to collect the curves of resistance vs. time from an experimental prototype of high voltage SF6 circuit breaker during opening and closing operations. Based on the analysis of the experimental results, both the travel extracted from the curve during closing operation and the average resistance extracted from the curve during opening operation can be used to implement the condition assessment of the contact ablation, and the combined data show more details about the main contacts and arcing contacts of high voltage circuit breaker.