Medium-voltage power distribution network single-phase ground fault route selection method based on fault procedure analysis

Abstract

The invention provides a single phase grounding fault line selection method for medium voltage distribution networks based on fault process analysis, which comprises the steps of calculating neutral point voltage, determining whether the neutral point voltage exceeds a preset threshold value, diagnosing fault type, determining whether the fault is a single phase grounding fault, describing fault process, positioning line selection area, selecting line for the fault, outputting result and finishing. The method can reflect the process of fault development and evolution intuitively and constitutionally, effectively selects the line for stable grounding with single phase grounding fault time more than 500 milliseconds, and can totally capture and describe transient fault during the fault process.

Description

technical field

[0001] The invention relates to a fault line selection method, in particular to a single-phase ground fault line selection method for a medium-voltage distribution network based on fault process analysis. technical background

[0002] In the prior art, for the line selection of a single-phase grounding fault in the medium-voltage distribution network, the fault line selection is usually performed based on the phenomenon of a single-phase grounding occurrence of a rise in the neutral point voltage of the power grid, as well as the grounding transient and steady state information during the period , this line selection scheme for ground faults only selects lines for a certain point of the ground fault. This scheme is not effective for high-resistance grounding or intermittent grounding fault line selection. It cannot be selected in the effective line selection interval of the fault development process, and for single-phase ground faults with a time greater than...

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