Electric energy quality disturbance detection and positioning algorithm

Abstract

The invention discloses an electric energy quality disturbance detection and positioning algorithm. The algorithm comprises the steps of S201, filtering noise of an electric energy quality disturbancesignal by adopting an improved wavelet threshold function, and determining a preset scale K through Fourier transform; S202, solving each intrinsic mode function of the electric energy quality disturbance signal through VMD, and extracting each mode amplitude and frequency characteristic information through Hilbert transform; and S203, realizing effective positioning of start and stop moments ofthe disturbance signal through a singular value decomposition principle. The technical problems that an intrinsic mode function obtained by adopting EMD and EEMD in an existing algorithm is prone to mode aliasing and endpoint effect, and power quality disturbance detection and positioning precision is not accurate enough are solved.

Description

technical field [0001] The invention belongs to the technical field of power systems, and in particular relates to a power quality disturbance detection and positioning algorithm. Background technique [0002] The number and capacity of non-linear, impulsive, and fluctuating loads in the power system continue to increase, resulting in a series of power quality disturbance problems such as harmonics, voltage sags, and short-term interruptions in the power grid. The problem of power quality disturbance has seriously affected the power grid and users. In order to take reasonable measures to improve power quality and improve the stability and reliability of power supply in the power system, it is first necessary to accurately detect and identify power quality disturbances. [0003] The wavelet transform in the existing feature extraction analysis methods has good time-frequency localization characteristics, but the detection effect of wavelet transform is easily affected by nois...

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Problems solved by technology

[0004] The technical problem to be solved by the present invention is to provide a power quality disturbance detection and location algorithm, which is based on improved wavelet threshold function, variational mode decomposition (VMD) and singular value decomposition, to solve the problems obtained by using EMD and EEMD in existing algorithms. The inherent mode function is prone to modal aliasing and endpoint effects, as well as the technical problems that the detection and positioning accuracy of power quality disturbances are not accurate enough

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