Arc suppression coil grounding system single-phase grounding line selection method

Abstract

The invention provides an arc suppression coil grounding system single-phase grounding line selection method. The method comprises a step of collecting bus three-phase voltage, bus zero sequence voltage and branch circuit zero sequence current of different times, a step of calculating the fundamental component instantaneous value u'0(t) of the bus zero sequence voltage according to the bus zero sequence voltage, and judging a phase with a fault according to the amplitudes of the bus three-phase voltage of different times and the fundamental component instantaneous value u'0(t), a step of calculating zero sequence current fundamental component instantaneous amplitude values I0M,x of different times and different positions of a branch circuit of a phase with the fault, and calculating the zero sequence current fundamental component instantaneous amplitude values I'0M, x of the branch circuit after the arc suppression coil compensation effect is completed, and judging whether the branch circuit has a grounding fault according to the zero sequence current instantaneous amplitudes before and after arc suppression coil compensation. A line with an arc suppression coil single-phase grounding fault can be accurately selected without the influences of a field and the polarity of a zero sequence current transformer, the accurate of line selection is effectively improved, the group judgment is not needed, and a line selection process is greatly simplified.

Description

technical field [0001] The invention relates to a grounding fault line selection method of a power system, in particular to a single-phase grounding line selection method for an arc suppressing coil grounding system. Background technique [0002] In the power grid, if the capacitive current of a single-phase ground fault exceeds 10A and is less than 100A-150A, the distribution network should adopt the neutral point grounding method through the arc suppression coil. For the arc suppression coil grounding system, when a single-phase ground fault occurs, due to The inductance current of the arc suppression coil compensates the single-phase grounding capacitive current, so that the fault characteristics of the single-phase grounding fault are not obvious, which makes it difficult to select the faulty line, that is, it is difficult to select the grounding fault line. [0003] In the prior art, some methods suitable for single-phase ground fault line selection in the arc suppressi...

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Problems solved by technology

[0002] In the power grid, if the capacitive current of a single-phase ground fault exceeds 10A and is less than 100A-150A, the distribution network should adopt the neutral point grounding method through the arc suppression coil. For the arc suppression coil grounding system, when a single-phase ground fault occurs, due to The inductance current of the arc suppressing coil compensates the single-phase grounding capacitive current, so that the fault characteristics of the single-phase grounding fault are not obvious, which makes it difficult to select the faulty line, that is, it is difficult to select the grounding fault line

[0003] In the prior art, some methods suitable for single-phase ground fault line selection in the arc suppressi

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