Residual current circuit breakers are important terminal protection appliances in low-voltage power distribution systems. They play a major role in preventing leakage accidents and protecting the personal safety of power users. The leakage protection module is composed of electronic components, and its parameter deviation and degradation cause parameter drift, which will cause the protection performance degradation of residual current circuit. Therefore, the simulation model of leakage protection module is established, and sensitivity analysis is used to identify the key components of leakage protection module. Considering the performance difference caused by tolerance, the Monte-Carlo simulation is used to obtain system performance degradation data. The protection system degradation caused by the degradation of components, and the reliability evaluation of leakage protection is realized according to the performance change, which can provide decision support for early design.
