Double-end traveling wave method-based medium-voltage distribution network cable short circuit fault positioning method

Abstract

The invention discloses a double-end traveling wave method-based medium-voltage distribution network cable short circuit fault positioning method. The method comprises the following steps of: 1, acquiring grounding current of an M end and an N end of a faulty cable; 2, extracting time tM and tN of two fault feature current traveling waves for correspondingly reaching the M end and the N end of thefaulty cable, and extracting arrival time tMr and tNr of first reflection waves at the M end and the N end of the two fault feature current traveling waves; and 3, calculating a distance normalization value dpu of a monitoring point from a fault point to the M end or N end of the faulty cable, and obtaining a position of the fault point on the faulty cable according to the size of the dpu. The method is capable of overcoming the synchronization problem of existing double-end traveling wave ranging and decreasing dependence on correct electric parameters of cable circuits, so as to greatly decrease the positioning error and reduce the influences, on refraction and reflection of fault feature current, of impedance-mismatched positions of circuits.

Description

technical field [0001] The invention relates to the technical field of power system line fault monitoring, in particular to a method for locating a short-circuit fault of a medium-voltage distribution network cable based on a double-terminal traveling wave method. Background technique [0002] In recent years, with the rapid development of urban construction and the improvement of people's living standards, the power consumption in central urban areas has increased sharply, and a large number of substations have gradually extended to the city center. Due to the restrictions of overhead corridors, the connection lines of these substations mainly use power cable lines. The number of new power cable lines put into operation continues to grow rapidly every year, and short-circuit faults also increase accordingly. The safe and reliable operation of cable lines is increasingly evident in supporting the stability of regional power grids and large-area reliable power supply. After a...

AI Technical Summary

Problems solved by technology

From the calculation formula of the fault point F above, it can be seen that although the double-ended traveling wave method only needs to detect the incident traveling waves at two line terminals, this fault location method is not only to accurately detect the propagation speed of the traveling wave on the detection line. , also depends on the synchronization of detection data, a small synchronization error will cause a large positioning error

Images