Virtual synchronous machine current harmonic suppression method and virtual synchronous machine control system

Abstract

The invention discloses a virtual synchronous machine current harmonic suppression method and a virtual synchronous machine control system. On the basis of a traditional voltage control type virtual synchronous machine control algorithm, three-phase current harmonic information is extracted, and the three-phase current harmonic information is fed forward to modulation waves through a proportionaldifferential (PD) regulator, so that the purposes of reducing current harmonics on the alternating current side of the virtual synchronous machine and improving the current quality are achieved. Considering the direct extraction difficulty of the harmonic current, the method employs a generalized quadratic integration (SOGI) method to extract the harmonic current, can effectively inhibit the high-frequency noise of an input current signal, and achieves the quick and accurate extraction of the harmonic current.

Description

technical field [0001] The invention relates to a current harmonic suppression method of a virtual synchronous machine suitable for flexible charging and discharging of an electric vehicle, and belongs to the technical field of power quality management. Background technique [0002] With the accelerated development of science and technology, energy issues and climate and environmental issues have become increasingly prominent. In order to realize the sustainable development of energy, all countries in the world are actively seeking effective ways of energy transformation. In order to comply with the direction of energy transformation, the automobile industry will also gradually realize "replacing oil with electricity". With the support of national policies and technological innovation of enterprises, the electric vehicle industry is booming. However, as the charging load of electric vehicles is random and decentralized, large-scale charging of electric vehicles will result...

AI Technical Summary

Problems solved by technology

The dead time of the switching device causes the deviation between the output voltage and the ideal modulation wave, and introduces certain odd harmonics; when the actual grid contains high harmonic components, these grid voltage harmonics bring the same frequency to the AC side current Harmonics; hardware parameters are affected by manufacturing accuracy, ambient temperature, electromagnetic interference and other factors, and cannot be completely consistent, which makes the current on the AC side unbalanced and aggravates the degree of distortion

A large amount of harmonic current injected into the power grid will affect the reliable operation of the equipment in the power system and reduce the power distribution efficiency. When the electromagnetic interference generated is serious, it will lead to the malfunction of the relay protection equipment and cause serious harm to the power grid.

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