Transformer partial discharge detection method based on optical fiber external cavity fabry-perot sensors

The invention relates to a transformer partial discharge detection method based on optical fiber external cavity fabry-perot sensors in the electrical transformer device partial discharge on-line monitoring technology field. Four optical fiber external cavity fabry-perot sensors are placed in oil in two temperature measuring tanks and two flange tanks at the top of a transformer and integrated with the transformer respectively. The tank structures are employed as ultrasonic signal collectors. An ultrasonic signal generated from transformer partial discharge is transferred to the tanks through transformer oil or the transformer solid structure and transferred to sensing heads through transformer oil in the tanks. The intensity of the signal received at the moment is independent of a position and an angle of a signal source, signals of the sensors are strong, and influences of the oil pressure inside the transformer on the sensors are avoided. The sensors at four positions work at the same time, and the situation is avoided that a signal is block by the internal structure of the transformer. The detection method is advantaged by high sensitivity, high signal collection capability, convenient operation and high anti-interference capability. Transformer partial discharge conditions can be detected well without extra auxiliary structures.