Research on smart substation protection assessment method considering multiple failure factors

Neglecting implicit failure factors leads to a large deviation between the failure to operate (FTO) frequency obtained from the reliability assessment of the existing smart substation protection system and the grid statistics. For this reason, this paper proposes a new protection assessment method. First, the reliability model of the protection system is established, taking into account the repairability of the protection system and the implicit failure factors. Then, based on the time series Monte-Carlo method, the reliability model is solved to obtain the protection system failure probability and FTO frequency. The simulation results show that the FTO frequency of the protection system obtained by considering multiple failure factors is more consistent with the grid statistics, and improving the self-test performance of the protection equipment can significantly improve the reliability of the protection system.