Voltage control method and device based on virtual synchronous generator

Abstract

The invention discloses a voltage control method and device based on a virtual synchronous generator. The method comprises steps that a d-axis current instruction value outputted by a virtual synchronous generator is acquired; obtaining a direct-current voltage of a power transmission system, and comparing the direct-current voltage with an upper limit value and a lower limit value of a preset voltage interval to obtain a comparison result; calculating to obtain a first current value through a proportional-integral controller according to the comparison result; performing summation operation on the first current value and the d-axis current instruction value to obtain a second current value; adjusting the virtual synchronous generator according to the second current value to obtain a standard voltage, wherein the standard voltage is any voltage value in a preset voltage interval, the certain desaturation time, namely switching time, is still needed when voltage deviation reaches a setmargin value at present, and the direct current voltage of the system is not controlled at the moment, so the voltage fluctuation is large, and stability of the system is reduced.

Description

Technical field [0001] This application relates to the technical field of power systems, and in particular to a voltage control method and device based on a virtual synchronous generator. Background technique [0002] With the increasingly prominent energy crisis and environmental problems, distributed power generation technology has received more and more attention. As the link between distributed power generation and microgrid, grid-connected inverters have been widely studied for their operating characteristics. Conventional grid-connected inverters have a fast impact speed, almost no moment of inertia, difficult to participate in grid regulation, unable to provide necessary voltage and frequency support for active distribution networks with distributed power sources, and unable to provide relatively poor stability for microgrids Provide the necessary damping effect. The virtual synchronous generator technology simulates the working principle of the synchronous generator thro...

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Problems solved by technology

[0004] This application provides a voltage control method and device based on a virtual synchronous generator, which is used to solve the problem of combining the virtual synchronous generator with the classic second-order voltage deviation control when the voltage deviation reaches the set margin value. , still needs a certain "de-saturation" time, that is, the switching time, and at this time the DC voltage of the system is uncontrolled, resulting in large voltage fluctuations and reducing the technical problem of system stability

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