Computer modelling and field testing of the trip mechanism for GIS

Circuit breakers (CBs) play a crucial role in power system reliability. Most CB failures observed in the field are related to operating mechanism. One of the useful approaches to effectively diagnose the mechanism failures of CBs is based on the trip coil current signatures. Using the simulation tool MapleSim, this study proposes a simulation model of CB trip mechanism to identify the CB failures and their causes. The impacts of intentional abnormalities on the trip coil current taken from the field testing of trip mechanism are scrutinised. The intentional abnormalities include trip coil operating voltage, trip coil circuit resistance, and shaft gap. To validate the effectiveness of the proposed MapleSim simulation model, the work made the trip coil current comparison between computer simulation and field testing. In this study, the field testing data are gathered from 23 kV gas insulated switchgear with good and various faulty conditions. The simulation‐based findings in this study provide a useful and valuable insight into the CB trip mechanism failures, offering more diagnostic advice to maintenance personnel. The proposed results are of great interest in CB diagnosis.