Measuring system and measuring method for power of power grid under harmonic wave condition

Abstract

The invention provides a measuring system and a measuring method for power of a power grid under a harmonic wave condition and is applied to the field of electric energy measuring. According to the technical scheme of the invention, the measuring system comprises a harmonic wave decoupling network used for converting an input signal into a sinusoidal signal, a parallel type second order generalized integrator-frequency locked loop structure used for detecting a mutually orthogonal signal of the sinusoidal signal and outputting a first orthogonal signal v', a second orthogonal signal qv' and anadjustment frequency omega' of a fundamental wave and each harmonic wave, a computing processing unit used for computing processing and a data storage unit used for storing computational data. The measuring system and the measuring method have the beneficial effects that instantaneous power of the fundamental wave and each harmonic wave in the power grid is monitored in real time, and by virtue of the detected instantaneous power data, active power and passive power of the fundamental wave and each harmonic wave of the power grid are measured, so that the defects that the traditional power detection is low in precision and low in response speed are overcome, and active power and passive power data of the fundamental wave and each harmonic wave is calculated in real time.

Description

technical field [0001] The invention relates to the field of electric energy metering, in particular to a metering system and method for grid power under harmonic conditions. Background technique [0002] The key to calculating the instantaneous power of the fundamental wave and each harmonic under harmonic conditions is the harmonic detection algorithm. At present, researchers have proposed a variety of harmonic detection algorithms for this point, among which the fast Fourier algorithm and the root mean square method are the most widely used. Among them, the fast Fourier algorithm will suffer from spectrum leakage and fence effects. When there is a sudden change in frequency, the errors of frequency, amplitude and phase calculated by the fast Fourier algorithm are relatively large, which cannot meet the requirements of accurate power calculation. The fast Fourier algorithm with windowed interpolation can reduce the error of the results calculated by the fast Fourier algor...

AI Technical Summary

Problems solved by technology

[0003] The purpose of the present invention is to provide a real-time monitoring of the fundamental wave and the instantaneous power of each harmonic in the power grid, and measure the fundamental wave of the power grid and the active power and reactive power of each harmonic through the detected instantaneous power data, which overcomes the traditional The shortcomings of low power detection accuracy and slow response speed, real-time calculation of the active power of the fundamental wave and each harmonic, and the measurement system and measurement method of the grid power under the harmonic conditions of the reactive power data

Images