Bi-directional power converter control method based on virtual synchronous motor

Abstract

The invention discloses a bi-directional power converter control method based on a virtual synchronous motor, and relates to the field of bi-directional power control in alternating-current and direct-current mixed micro-grids. A bi-directional power converter is of a three-phase three-leg structure formed by a switch tube and provided with a direct-current-side capacitor and an alternating-current-side filter inductor, alternating-current-side output voltage of the bi-directional power converter is equivalent to exciting electromotive force of the synchronous motor, alternating-current-side grid voltage is equivalent to terminal voltage of the synchronous motor, filter inductance is equivalent to armature winding of the synchronous motor, the bi-directional power converter can serve as the virtual synchronous motor after equivalence is achieved, an inertia simulation unit of the bi-directional power converter is provided with the direct-current-side capacitor, bi-directional transmission of energy is achieved by the aid of a virtual frequency controller, a virtual excitation regulator and a virtual motor control unit, direct-current voltage variation and alternating-current frequency fluctuation are decreased, the bi-directional power converter has a certain inertia, dynamic response of a system is improved, and the stability of the system is improved.

Description

technical field [0001] The invention relates to the field of bidirectional control of an AC-DC hybrid microgrid, in particular to a bidirectional power converter control method based on a virtual synchronous motor, which is suitable for realizing bidirectional flow of energy between AC and DC microgrids. Background technique [0002] With the increase in the penetration rate of distributed power generation, microgrid, a technology that combines the advantages of different energy sources and has good controllability, is becoming more and more mature. Microgrids can be divided into AC microgrids, DC microgrids and AC / DC hybrid microgrids according to the nature of source-load. The AC-DC hybrid microgrid can connect the AC and DC microgrids in the same network in an orderly and independent manner, simplify the structure of the microgrid, save power conversion devices, reduce system losses, make the control more flexible, and improve the economy of the entire system and reliabi...

AI Technical Summary

Problems solved by technology

[0004] In order to solve the problems of the lack of moment of inertia of the AC-DC hybrid micro-grid, the rapid response of the power electronic converter, the low frequency stability, the limitation of the increase of the penetration rate of renewable energy, and the problem that the inertia is not considered in the control of the existing bidirectional power converter, Provides a bidirectional power converter control method based on virtual synchronous motor

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