Online condition monitoring methodology for relay protection based on self-test information

A microprocessor-based relay protection unit has strong self-test capability that allows the device to monitor operation conditions and diagnose problems by itself. Based on the characteristics of microprocessor-based protection software and hardware architecture, this paper proposed an online health monitoring methodology using the self-test information of protection units. In accordance with expression modes and acquisition methods, self-test Information of protection equipment can be divided into following four categories, state self-test information, analog self-test information, description self-test information and statistics self-test information. Considering all factors affecting the health status of protection units, this paper established a generic evaluation model of health status. The master station for condition monitoring collects self-test information and evaluates the health status of protection unit online, and provides guidance for condition-based maintenance.