Alternate switching function testing method for small-current fault line selection device

Abstract

The invention discloses an alternate switching function testing method for a small-current fault line selection device. A power system real-time digital simulator, a power amplifier and the small-current fault line selection device with an alternate switching function. An RTDS real-time simulator generates a grounding signal, and amplifies the grounding signal through the power amplifier to the small-current fault line selection device with the alternate switching function; the small-current fault line selection device with the alternate switching function receives the amplified signal and analyzes the signal, N lines with a larger probability are selected for alternate switching, and then a tripping signal is fed back to a GTFPI board card of the power system real-time digital simulator;a tripping operation is carried out on the selected lines by controlling a corresponding outgoing line switch action in a line simulation model, and the small-current fault line selection device withthe alternate switching function judges whether line selection is correct or not according to a tripping result of an outgoing line switch. The whole testing process is automatically controlled and executed by RSCAD software, so that automatic control over the testing process is achieved.

Description

technical field [0001] The invention belongs to the technical field of line selection function testing of electric power systems, and in particular relates to a method for testing the wheel cut function of a small current grounding line selection device. Background technique [0002] Most of the medium and low voltage distribution networks in my country adopt the neutral point indirect grounding method. When a single-phase ground fault occurs in this type of power grid, only the capacitive current of the line flows through the ground fault, and its value is only a few amps to 20 or 30 amps. Since no short-circuit current is generated and the line voltage is still symmetrical, it does not affect For the normal power supply of users, it is allowed to continue to run for 1 to 2 hours according to the regulations. At this time, the non-fault phase-to-ground voltage rises to the line voltage level, which may cause ground-to-ground breakdown at its weak insulation, thereby expand...

AI Technical Summary

Problems solved by technology

However, in the current test of small current grounding line selection devices, the test method of small current grounding line selection devices with wheel cut function has not yet been involved.

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