A method of line selection for arc-suppression coil decentralized compensation for grounding faults in distribution network

Abstract

The invention discloses a line selection method for a single-phase ground fault in an arc-suppression coil decentralized compensation system. The steps are as follows: (1) monitor the neutral point displacement voltage of the power grid and use it as a criterion for a single-phase ground fault, and a single-phase ground fault occurs Afterwards, the device sends out an alarm signal; (2) after receiving the alarm signal, sample the zero-sequence current of each line; (3) disconnect the switch between the neutral point and the main arc suppression coil, so that the arc suppression coil exits; ( 4) Sampling the zero-sequence current of each line again and putting it into the main arc-suppression coil; (5) Carry out rated calculation of the zero-sequence current before and after the arc-suppression coil is cut off; (6) Make a difference and compare the calculation results of (5) Zero-sequence current variation of each line before and after; (7) Calculate the characteristic value of zero-sequence current change of each line according to the calculation results of (6) and perform integral processing to select the faulty line. The invention can accurately select the line where the single-phase grounding fault occurs in the arc-suppression coil decentralized compensation system, which is beneficial to improving the safety of the power grid.

Description

technical field [0001] The invention belongs to the field of electric power system automation, and is a single-phase grounding fault line selection method of a power system distribution network, which is mainly suitable for the decentralized compensation grounding system of the arc suppression coil of the distribution network, and specifically relates to the arc suppression based on the characteristic value of the zero-sequence current change Coil dispersion compensation method for ground fault line selection of distribution network. Background technique [0002] The grounding of the neutral point through the arc suppression coil has the advantages of suppressing arc overvoltage and high reliability of system power supply, so it has always been the main neutral point operation mode of the 35kV and below urban distribution network in my country. [0003] With the increase in power demand, the expansion of the grid scale and the improvement of the degree of line cables, the sy...

AI Technical Summary

Problems solved by technology

[0009] Based on the zero-sequence current fault characteristics of each line, the present invention proposes a new line selection method on the basis of comprehensively studying the technical characteristics and practical application effects of the existing small current grounding line selection method, which can really improve my country's Current Situation of Inaccurate Line Selection of Resonant Grounding System in Distribution Network

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