Small-current grounding fault line selection method based on arc suppression coil

Abstract

The invention discloses a small-current grounding fault line selection method based on an arc suppression coil. The small-current grounding fault line selection method includes: transferring a parallel resistor mounted on a primary side of the arc suppression coil primarily into a parallel line selection resistor mounted on a secondary side of the arc suppression coil by adding a secondary winding of the arc suppression coil; and utilizing the parallel line selection resistor mounted on the secondary side of the arc suppression coil to enable active power increment flowing through grounding circuits to increase by 1-10A when a system has grounding faults. Active component of each normal circuit is small, so that increment of the faulty circuits is obvious, and directions of active current of the grounding circuit and active power of non-grounding circuit are opposite. According to an arc suppression coil electromagnetic equivalence principle that electromagnetism of the arc suppression coil is equivalent to that of the parallel resistor utilized for line selection on the primary side of the arc suppression coil, the active current increment and direction of loop circuits are tested to perform fault line selection, so that line selection accuracy can be realized, problems and risks in the existing arc suppression coil primary side line selection resistor switching are eliminated successfully, and safety and reliability of power grids are improved.

Description

technical field [0001] The invention belongs to the technical field of resonant grounding line selection for power distribution networks, and in particular relates to a line selection method based on an arc suppression coil for small current grounding faults. Background technique [0002] At present, the neutral point of my country's distribution network mainly adopts the arc suppressing coil grounding method, which is also a small current grounding system. The fault current generated by the small current grounding fault is very small, which is less harmful to electrical equipment, communication and personal safety. The line voltage between the three-phase voltages remains basically unchanged and does not affect the power supply to the load. Continue to run for 2 hours under grounding conditions to avoid the impact of sudden power interruption on users. Although the small current grounding fault does not affect the normal operation of the power grid, the arc overvoltage cau...

AI Technical Summary

Problems solved by technology

[0006] The purpose of the present invention is to provide a small current grounding fault line selection method based on the arc suppressing coil to solve the problems that the existing fault line selection method is easy to cause closing inrush current, power grid fluctuations, low safety and complex line selection process

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