Power transmission and distribution line partial discharge fault on-line detection method and apparatus thereof

The invention provides a power transmission and distribution line partial discharge fault on-line detection method and an apparatus thereof, belonging to the measurement field. A method of on-line remote orientation focusing pick-up/positioning is employed to capture a supersonic wave signal generated in a discharge process, a heterodyne method is used to convert the picked supersonic wave signal into a sound/electrical signal which can be distinguished by detection personnel, according to a value size or change of sound pressure/voltage, whether a position where a partial discharge fault easily happens exists a contaminant flashover phenomenon or not and a degree of contaminant flashover are determined qualitatively and quantificationally, thereby, intensity of contaminant flashover of the position where the partial discharge fault easily happens and a size of threat to a system are determined, manpower and regular inspection cost can be greatly reduced, previous power failure time workload is reduced, safet