Analysis of Power Transformer Differential Relay Performance Based on Routine Maintenance Test Results at Baloi 150 kV Substation

Abstract

Power transformers are vital equipment in electrical power distribution systems, functioning to transmit power between different voltage levels. Given their important role and high investment costs, transformers must be protected by a reliable primary protection system, namely Differential Relays. Over time, the electronic components in the relays can experience a decline in performance, which has the potential to cause operational failures. confirming that the protection system operated reliably, selectively, and in accordance with its design specifications. The FMEA analysis also identified that relay setting verification and operating time evaluation are the highest-priority aspects for continuous monitoring and preventive maintenance to maintain long-term protection system reliability. Overall, the differential relay protection system was verified to be in good operating condition and ready to provide effective protection for the power transformer under both normal operating conditions and internal fault conditions