Single-phase earth fault positioning device for electrical power distribution network

The invention disclose a new positioning method of a distribution network single-phase earth fault, which is applicable to a 3-60 kV neutral point ineffective earth grid. The principle of the positioning method is that: firstly, a high-voltage DC signal is poured into a circuit starting end and the DC signal is detected along the circuit so as to determine a fault area; then a high-voltage AC signal is poured into the circuit starting end, and the AC signal is detected along the circuit so as to determine the position of a fault point. A positioning device developed on the basis of the invention consists of two parts: a high-voltage signal source and a signal detector, wherein, the high-voltage signal source consists of a voltage inverter, a constant flow source, a transformer and a rectifier bridge and is used for pouring a high-voltage DC signal and a high-voltage AC signal; the signal detector comprises a DC detector and an AC detector, wherein, the DC detector consists of a Hall DC detector, a Bluetooth wireless sender and a Bluetooth wireless receiver and is used for measuring the DC signal; while the AC detector consists of an AC electromagnetic field inductor and a signal processing and display segment and is used for measuring the AC signal. The method and the device have mature technique and high reliability.