Ground fault location method for resonant grounded system based on phase voltage and current phase

Abstract

The invention discloses a resonance grounding system single phase grounding fault section positioning method utilizing phase voltage current break variable phase characteristics. The method comprises steps that step 1, a break variable of a phase voltage and a break variable of a phase current of each data acquisition device are calculated; step 2, phases of all frequency components of the phase voltage break variables and the phase current break variables are calculated through utilizing a matrix pencil algorithm; step 3, phase angle difference dph (50) of a phase voltage break variable power frequency component and a phase current break variable power frequency component of one same acquisition device is acquired; step 4, phase angle difference dph (fm) of any high frequency component of the phase voltage break variable and any high frequency component of the phase current break variable is calculated; step 5, an absolute value dj of the difference of the dph (50) and the dph (fm) is calculated; and step 6, magnitudes of all the dj are determined, and a fault section is identified. The method is advantaged in that zero sequence voltages and currents are not required, the phase voltage and the phase current of each phase are only required, compared with a resonance grounding system section positioning method based on the zero sequence voltages and currents, the method has further has properties of autonomy, no need of filtering and easy realization.

Description

technical field [0001] The invention belongs to the technical field of relay protection for distribution networks, and in particular relates to a method for locating a single-phase ground fault section of a resonant ground system. Background technique [0002] my country's distribution network mostly adopts the neutral point grounding method through the arc suppression coil, and in order to avoid resonance overvoltage, it is usually a compensation operation. The probability of a single-phase ground fault in the distribution network is very high. Because the existing regulations require that the resonant grounding system can continue to run for 1 to 2 hours after a single-phase ground fault occurs, during this period the fault is eliminated by manual line inspection. The automation level of single-phase ground fault is low. In 2015, the National Energy Administration issued the "Action Plan for Construction and Transformation of Distribution Networks (2015-2020)". The docume...

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Problems solved by technology

The probability of a single-phase ground fault in the distribution network is very high. Because the existing regulations require that the resonant grounding system can continue to run for 1 to 2 hours after a single-phase ground fault occurs, during this period the fault is eliminated by manual inspection. low level of automation for single-phase-to-ground faults

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