Reliability assessment approach for relay protection devices based on the triple Weibull model

The reliable operation of the relay protection device is crucial for ensuring the safety and stability of the power system. Quantitative evaluation of protection device reliability and accurate analysis of its change pattern in different operating stages can facilitate optimization of component selection, improvement of production processes, enhancement of installation and debugging proficiency by construction units, as well as elevation of operational and maintenance capabilities including overhaul and inspection. In this study, we extensively investigate the characteristics of the product limit estimation method and triple Weibull distribution model. Empirical reliability is calculated using the product limit estimation method, while empirical reliability is fitted using the triple Weibull distribution model with corresponding parameter fitting. By employing this model, we calculate the reliability and failure rate for six sample space protection devices, analyzing parameter characteristics across different operational stages. This proposed approach enables reliable analysis for various sample space protection devices while effectively validating both the triple Weibull distribution model's validity and significance through case studies. This research work holds great importance in promoting reliability analysis based on operating data from protection devices.