Online partial discharge monitoring and positioning method and system for distribution cable

The invention provides an online partial discharge monitoring and positioning method and system for a power distribution cable. The method comprises the following steps: acquiring pulse signals from the two ends of the preset distance of a measured cable through a pulse current sensor; carrying out signal processing on the pulse signal, and obtaining transmission time T and transmission speed V ofthe pulse signal passing through two ends of a tested cable, and a partial discharge signal on the tested cable; and determining the position of partial discharge on the tested cable according to thepartial discharge signal, the transmission time T and the transmission speed V. The problem that how a system for realizing online partial discharge monitoring and having certain positioning precision can identify the noise of a partial discharge source and the external part in a cable and in switch cabinets/ring main units/cable branch boxes at two ends is solved, the double-end transmitting, receiving and transmitting f