Harmonic Analysis Method of Power Quality Harmonic Analyzer

Abstract

The invention discloses a harmonic analysis method of a power quality harmonic analyzer, wherein the harmonic analysis method is achieved based on the improvement on the quasi-synchronization DFT. The harmonic analysis method comprises the steps that an electrical signal X on which the harmonic analysis needs to be carried out is sampled in a power grid, and data of W+2 sampling points are sampled at equal intervals; when the harmonic analysis is carried out according to the quasi-synchronization DFT, the position of frequency domain sampling is changed according to the drifting value, seen in the specification, of the signal frequency and then the frequency domain sampling position confirms to the value in the specification; the amplitude, seen in the specification, of all harmonics of the electrical signal X and the initial phase angles, seen in the specification, of the harmonics of the electrical signals X are worked out; the amplitude percentage, seen in the specification, of the amplitude Pk of the higher harmonics of the voltage signal V and the current signal I to the amplitude of the fundamental harmonic P1 is worked out, and the phase angle difference seen in the specification is worked out, and the amplitude percentage and the phase angle difference are output and displayed.

Description

[0001] This application is a divisional application of the invention patent application with the application number: 201110322629.4, the invention name is "A Harmonic Analysis Method for Power Quality Harmonic Analyzer", and the application date is: October 21, 2011. technical field [0002] The invention relates to the technical field of harmonic analysis of power quality, in particular to a high-precision harmonic analysis method. Background technique [0003] Harmonic analysis technology is widely used in many fields such as power quality monitoring, electronic product production inspection, and electrical equipment monitoring. It is an important technical means for power grid monitoring, quality inspection, and equipment monitoring. [0004] In the power supply network, the generation of harmonic phenomena is mainly caused by large-capacity power equipment, power rectification or converter equipment, and other nonlinear loads. In recent years, with the rapid development ...

AI Technical Summary

Problems solved by technology

[0008] In engineering applications, harmonic analysis always performs limited sampling and it is difficult to achieve strict synchronous sampling

In this way, when quasi-synchronous DFT is used for harmonic analysis, there will be long-range leakage due to the truncation effect and short-range leakage due to the fence effect, making the analysis results inaccurate and even unreliable

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