Abstract: The result obtained from traditional reliability evaluation methods is the overall level of a collection of electrical products which mainly based on probability and statistics theory, strongly relying on lifetime data, and not suit for operating reliability evaluation. Electromagnetic relay, for example, a performance assessment method based on condition monitoring data and overall lifetime data is proposed. Calculate the baseline hazard rate function according to contact status monitoring and lifetime data from the electrical contact test and determined Weibull distribution as relay’s lifetime distribution after fitting test. Taking contact resistance and Weibull distribution as model covariate and baseline hazard rate function form respectively. Model parameters could be obtained by maximum likelihood estimation method. Weibull proportional hazards model for performance evaluation for relays is established and monitoring interval dynamic prediction method is presented on this basis. Application example is given to verify the effectiveness of this method, providing support for devices change and maintenance decision.

Key words: electromagnetic relays, performance assessment, proportional hazards model(PHM), status monitoring, Weibull distribution