A real-time detection method for power quality transient disturbance

Abstract

The invention discloses a method for detecting transient disturbance of electric energy quality in real time. The method comprises the following steps of: 1) constructing complex wavelets on the basis of a basic wavelet function; 2) lifting the constructed complex wavelets according to a basic principle of lifting wavelets, and obtaining a lifting scheme of the complex wavelets by using a Euclidean decomposition algorithm; 3) performing lifting transformation on fundamental frequency signals and transient disturbance signals of an electric network respectively by using the lifting scheme; 4) subtracting the phase DP obtained after lifting the disturbance signals from the phase SP obtained after lifting the fundamental frequency signals, namely ensuring phase information W=SP-DP, and simultaneously, causing amplitude information to be the amplitude obtained after lifting the disturbance signals; 5) performing real-time detection and positioning on the disturbance signals by using the amplitude information and phase information; and 6) repeating the steps from the step 3) to the step 5), and continuously positioning and detecting the disturbance signals and estimating the disturbance amplitude in real time. The method is low in time consumption and high in instantaneity, is simple to implement, and has high algorithm accuracy; and by using the method, the transient disturbance signals can be accurately positioned and the amplitude can be accurately estimated.

Description

technical field [0001] The invention relates to a real-time detection method for power quality transient disturbance. Background technique [0002] In the modern power system, with the wide application of nonlinear loads and the increase of sensitive electronic equipment in the power grid, the power quality pollution suffered by the power system is becoming more and more serious. In order to ensure the normal and reliable operation of various electrical equipment, effective measures must be taken to improve the power quality. In practice, power quality problems are divided into steady state and transient state. [0003] In order to accurately detect power quality disturbances and improve power quality, in-depth research has been carried out at home and abroad, and many methods have been proposed, such as wavelet transform, S transform, short-time Fourier transform (STFT) and so on. However, there are various defects in the above methods. For example, the shortcoming of STF...

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Problems solved by technology

Although wavelet transform has good time-domain-frequency-domain localization characteristics, it is suitable for analyzing transient and abrupt signals. In the aspect of detecting high-frequency disturbances, wavelet transform method is very advantageous. However, for low-frequency disturbances, such as voltage sags, Voltage swells, etc., but cannot be detected and positioned well. At the same time, the wavelet transform has a large amount of computation

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