Protection device monitoring using data from power quality monitoring devices

In this paper, a model based expert system method was developed for monitoring the operation of protection devices based on the data obtained from power quality monitoring devices placed at the substations. First, models of physical protection devices were developed, and then actual power quality monitoring data were fed to the models to get an estimate of protection device operation. Test results, based on the actual data, show that, the proposed method can identify which protection device has operated to clear an observed fault, especially when there are multiple protection devices on the system.