Event driven maintenance based on protective relays data

Event driven maintenance is becoming extremely important in the efforts of utilities to deal with reduced personnel and at the same time increasing customer requirements for improved power quality and reliable supply of electric power. Modern microprocessor based relays measure and calculate numerous analog parameters and provide additional monitoring functions that allow the transition from scheduled into event driven maintenance, without the need for addition of any specialized equipment. The paper presents a variety of tools, available in microprocessor based relays that can help the utility to determine the need for substation equipment maintenance based on user defined alarm signals from the protective device. The relays have built in analysis tools that process the fault data and convert it to ready to use information, thus reducing the need for protection, control and maintenance personnel in the decision process. They implement different algorithms based on recorded or measured samples of currents and voltages