Distorted signal electric quantity metering method based on empirical wavelet transform

Abstract

The invention discloses a distortion signal electric quantity metering method based on empirical wavelets. Firstly, original voltage signals and current signals in a power grid are collected as to-be-observed signals; empirical wavelet transform is carried out on the to-be-observed signals, specifically, spectrum division is carried out adaptively on the to-be-observed signals to divide the signals into different modes, and then, empirical wavelet transform is carried out on each mode to decompose the to-be-observed signals; and fundamental wave signals and distortion signals of the to-be-observed signals are extracted from an empirical wavelet transform decomposition result to obtain active power P. The problems that the wavelet basis and decomposition layer number need to be selected in wavelet transformation of an existing electric quantity metering technology, self-adaptive capacity is poor, self-adaptive detection cannot be achieved, wavelet decomposition has the frequency aliasing phenomenon, and the existing technology is limited by the Heisenberg uncertainty principle are solved.

Description

technical field [0001] The invention belongs to the technical field of electricity metering automation, and relates to an empirical wavelet-based distorted signal electricity metering method. Background technique [0002] In the modern power system, the share of non-linear loads such as various induction heating furnaces, electric locomotives, power electronic switchgear, and electrical and chemical industrial equipment is rapidly increasing. The increase of such loads makes the asymmetry of the supply voltage intensified and the volatility is also increasing. Seriously, a large number of harmonic signals are generated, which makes the power quality of the power grid deteriorate day by day, and the signal distortion of the power grid is serious. In addition to the fundamental wave, the voltage and current signals are also doped with a large number of quasi-periodic, time-varying, and non-stationary distortion signals, which seriously affect the power quality of other users, ...

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Problems solved by technology

[0005] The purpose of the present invention is to provide a distorted signal power metering method based on empirical wavelet transform to solve the problem of poor self-adaptive ability when wavelet base and decomposition layers are selected for distorted signal power metering in wavelet transform in the prior art, And there is frequency aliasing phenomenon between frequency bands in distorted signal power metering in the prior art, which fails to realize adaptive detection and is subject to the Heisenberg uncertainty principle

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