Monitoring Partial Discharge in Transformer Oil Using a Newly Designed Single Mode Fiber Optic Sensor

Abstract

The quest of finding accurate fault diagnostics and assessing the oil quality of electrical power transformer for life-long safeguard is never-ending. The longevity of transformers function is critically decided by the quality of its insulation. Developing a sensor for accurate and efficient detection of partial discharge (PD) in high voltage transformer oil in assessing its insulation quality and integrity is the key issue. The optical fiber sensor being economical and highly reliable can provide ultimate safety due to total isolation from the high voltage line. The small electrical sparks called PD appears in the insulating oil due to the electrical breakdown of interior air or the occurrence of highly non-uniform electric field needs to be monitored. The acoustic emission (AE) that occurs near the discharge zone is used to detect PD. We compare the sensitivity of single mode fiber optic sensor (FOS) with conventional capacitive sensor (CS). These sensors are immersed in a mineral oil tank (transformer) fitted with two steel electrodes those are connected to different high voltage sources.