Multiwavelet-based random non-linear load active energy metering method

Abstract

The invention discloses a multiwavelet-based random non-linear load active energy metering method. The research on a novel multiwavelet-based random non-linear load active energy metering method is an issue with great theoretical significance and application value in the electrical energy metering field. The method comprises the following steps of: synchronously collecting voltage and current through a synchronous collecting circuit, decomposing the frequency bands of the voltage and the current by using a multi-wavelet decomposition algorithm, reconstructing fundamental wave, harmonic wave, flickering and impact voltage and current, metering fundamental wave, harmonic wave, flickering and impact active power through active energy metering of identical-frequency band, metering distortion active power generated by interaction of frequency signals through active energy metering of different frequency bands, and determining a random non-linear load source according to the directions of the harmonic wave active power, the flickering active power, the impact active power and the distortion active power so as to provide reference for active energy metering and management of random non-linear load. The multiwavelet-based random non-linear load active energy metering method provided by the invention is used for realizing random non-linear load active energy metering.

Description

Technical field: [0001] The invention relates to a multi-wavelet-based random nonlinear load active energy metering method. Background technique: [0002] In the modern power grid, in addition to the stable fundamental and harmonic signals, quasi-periodic and time-varying non-stationary distortion signals also appear, which lead to changes in the power flow of the complex power grid, highlighting the inadequacy of the existing energy measurement methods. Accurate and unreasonable. The traditional energy metering method under harmonic and impact load or nonlinear load conditions is based on sinusoidal circuit power theory and traditional non-sinusoidal circuit power theory, and cannot be applied to the existing random nonlinear load conditions because of Traditional circuit power theory cannot deal with time-varying random non-stationary signals and mixed signals of periodic signals and random non-stationary signals. At the same time, the needs of the national smart grid co...

AI Technical Summary

Problems solved by technology

[0006] The disadvantage of the existing technology is that in the power system, random nonlinear loads cause harmonics, voltage fluctuations and flicker, transient impact, non-periodic nonlinearity and various random signals to exist simultaneously in the power system, and the accurate measurement of electric energy Influenced by measuring harmonics, nonlinearity or flicker alone, there are large errors in the results

[0007] The disadvantage of the existing technology is that in the power system, FFT can only deal with traditional cycle stationary signals, and is only suitable for electric energy measurement under harmonics

As a modern signal processing technology, wavelet transform can be applied to electric energy metering of impact loads, but because wavelet cannot have orthogonality, tight support and symmetry at the same time, there is a problem of spectrum aliasing in wavelet decomposition. Accuracy of energy metering is sacrificed

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