Power grid harmonic phase analysis method, system and device

Abstract

The invention relates to a power grid harmonic phase analysis method, system and device. The method comprises the following steps: acquiring a voltage waveform signal of a concerned bus and a current waveform signal on a power consumer feeder line; dividing the statistical time into a plurality of calculation windows; in each calculation window, intercepting a preset number of cyclic waves from the voltage waveform signal and the current waveform signal; performing fast Fourier transform on the preset number of cycles to obtain a harmonic phasor of each phase of voltage signal and a harmonic phasor of each phase of current signal; according to the harmonic phasor of each phase of voltage signal, obtaining a zero-crossing point moment of a rising edge of each phase of fundamental wave voltage, and according to the harmonic phasor of each phase of current signal, obtaining a phase of each harmonic wave of each phase of current signal at the zero-crossing point moment of each phase; and performing analysis based on all phase data obtained within the statistical time. According to the power grid harmonic phase analysis method, system and device, harmonic current phase distribution can be reflected more accurately, and the phase sequence fault-tolerant capability is achieved.

Description

technical field [0001] The invention relates to the technical field of power quality analysis of a power grid, in particular to a method, system and device for analyzing a harmonic phase of a power grid. Background technique [0002] Modern power supply requires high reliability, flexible control, and convenient application, but the problem of poor power quality caused by power system pollution has always existed: on the one hand, with various new user loads, especially nonlinear and harmonic generation The large-scale application of various power electronic devices has brought adverse effects on the power quality of the power grid; on the other hand, users have higher and higher requirements for power supply reliability, especially many precision electronic Quality sensitivity is getting higher and higher. Therefore, it is urgent to strengthen the harmonic management of distribution network. [0003] The harmonic management of distribution network is an important basic wo...

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Problems solved by technology

[0002] Modern power supply requires high reliability, flexible control, and convenient application, but the problem of poor power quality caused by power system pollution has always existed: on the one hand, with various new user loads, especially nonlinear and harmonic generation The large-scale application of various power electronic devices has brought adverse effects on the power quality of the power grid; on the other hand, users have higher and higher requirements for power supply reliability, especially many precision electronic Sensitivity to quality is increasing

[0005] (1) Since the harmonic voltage at the point of interest is jointly affected by the background harmonic voltage and the load harmonic current, using the harmonic voltage as a reference for the phase distribution characteristics of the typical load harmonic current will make the phase distribution of the harmonic current appear relatively Large deviation, so the harmonic impedance angle cannot accurately characterize the phase characteristics of the harmonic current

[0006] (2) Harmonic impedance angle cannot have phase sequence fault tolerance

The ABC three-phases in different low-voltage power loads may not be completely corresponding, that is, the ABC three-phases of one distribution transformer may correspond to the BCA three-phases of another distribution transformer. If the harmonic current phase distribution does not have phase Sequence fault tolerance, if mistakenly regard B-phase data as A-phase data, wrong results may be obtained

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