Line selection method for medium-voltage power distribution network fault traveling wave

Abstract

The invention discloses a line selection method for medium-voltage power distribution network fault traveling wave. The method comprises the following steps: mounting traveling wave recording devices at a substation in a medium-voltage power distribution network and at the tail end of each branch of each main trunk circuit and recording the fault traveling wave arrival time; simulating a substation bus fault, testing fault traveling wave, and calculating time difference of the traveling wave arrival time recorded by the tail end of each branch on each trunk circuit and the traveling wave arrival time recorded by the substation to obtain a reference time array; calculating the time difference of the traveling wave arrival time recorded by the tail end of each branch on each trunk circuit and the traveling wave arrival time recorded by the substation to establish a fault time array in case of fault of the power distribution network; calculating a correlation coefficient of the fault time array and the reference time array of each trunk circuit, comparing the sizes of the correlation coefficients of all trunk circuits, and judging the fault circuit. The method is not limited by the fault type, and has the advantages of good fault tolerance capacity, easiness in operation, reliable line selection and high practicability.

Description

technical field [0001] The invention relates to a fault traveling wave line selection method of a medium-voltage distribution network. Background technique [0002] my country's medium-voltage distribution network widely adopts the non-effective neutral point grounding operation mode. Overhead lines are distributed in the wilderness, and cable lines are buried deep underground. It is difficult to find faults, which seriously affects the safe and stable operation of the power grid and people's production and life. Since the single-phase ground fault current of the non-effectively grounded distribution network at the neutral point is small, it generally does not affect the continuous power supply of the load. The existing regulations allow the distribution network to continue to operate with a single-phase ground fault for 1 to 2 hours. However, with the development of the distribution network, the feeder lines of substations are increasing year by year and the wide applicatio...

AI Technical Summary

Problems solved by technology

Due to the small grounding fault current of the distribution network, it is difficult to detect the fault; the existing various line selection devices are affected by factors such as complex fault conditions, weak fault current, on-site electromagnetic interference and unbalanced current, and the on-site operation effect is not ideal. Line accuracy is not high

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