Method of EFPI Fiber Sensor in Partial Discharge Detection

Among the detection methods of partial discharge in high voltage electrical equipment, optical method is new and competitive. This paper presents a diaphragm type optical fiber EFPI (External Fabry-Perot Interfering) sensor, which is developed by external Fabry-Perot interfering method and used for detection of partial discharge. We made a needle-plane electrode in oil, detected it with joint detection of optical fiber sensor and VHF (Very High Frequency) sensor. The study finds: optical fiber sensor can pick up signals effectively on PD (partial discharge) detection in early stage, have high sensitivity. The signal picked up by optical fiber sensor and VHF sensor not only has well correspondence, which can identify partial discharge signals effectively, but also has broad application, such as the on-line detection of transformer or other high voltage electrical equipment.