Power distribution network single-phase earth fault arc extinguishing method based on phase-locked loop

Abstract

The invention relates to a power distribution network single-phase earth fault arc extinguishing method based on a phase-locked loop, and the method comprises the following steps: decomposing a collected zero-sequence voltage signal into two paths of orthogonal signals after a single-phase earth fault happens to a power distribution network, and carrying out the amplitude and phase decoupling of the signals in a dq coordinate system; controlling the q-axis component to be zero to obtain a zero-sequence voltage amplitude; converting the instantaneous angular frequency into a phase angle to obtain a zero-sequence voltage phase angle; and calculating a reference arc extinction injection current by using the obtained amplitude and phase of the zero-sequence voltage, calculating an injection compensation current according to the reference arc extinction injection current, and controlling the converter to inject the injection compensation current into the neutral point of the power distribution network. According to the invention, the phase and amplitude information of the target voltage can be accurately and quickly tracked, the compensation current is accurately output, the extinguishing of the arc is effectively promoted, and the steady-state performance of the arc extinguishing system is improved.

Description

technical field [0001] The invention relates to the technical field of distribution network safety design, in particular to a phase-locked loop-based arc suppression method for a single-phase grounding fault in a distribution network. Background technique [0002] Due to the complex climate, geology, environment and other operating conditions along the distribution network, single-phase ground faults are prone to occur, and the extensive use of cables leads to the increase of line-to-ground capacitance current, which makes the single-phase ground fault current rise accordingly. While a large amount of investment in power electronic equipment promotes the flexible development of the distribution network, it also leads to a certain amount of active power and harmonic components in the single-phase ground fault current. Because the traditional arc suppression coil can only compensate for the reactive power in the ground fault current The component, the ground fault residual cur...

AI Technical Summary

Problems solved by technology

In the process of calculating the compensation current, there are usually problems such as sudden changes in the target voltage and harmonic influences that lead to abnormal reference currents. Therefore, it is necessary to find an accurate and feasible method for collecting voltage information to ensure reliable arc suppression in the arc suppression system.

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