Current compensation based power decoupling method of virtual synchronous power generator

Abstract

The invention discloses a current compensation based power decoupling method of a virtual synchronous power generator. The power decoupling method comprises the following steps of 1) acquiring a dq component of an output current of a virtual synchronous motor through sampling, acquiring power angle information by a mechanical property simulation part, and further calculating reactive power-power angle decoupling current compensation instruction; 2) acquiring transient state variable quantity of a virtual excitation electromotive force, and calculating active power-voltage decoupling current compensation instruction by combining the dq component, obtained in the step 1), of the output current; and 3) correcting the reactive power-power angle decoupling current compensation instruction obtained in the step 1) and the active power-voltage decoupling current compensation instruction obtained in the step 2) to obtain a new current instruction, and obtaining a switching signal through a current ring to drive a switching network. The invention proposes the power decoupling method applicable to the virtual synchronous motor, and the influence of a power angle on droop control can be eliminated; and compared with the prior art, the power decoupling method has the advantages that dynamic power oscillation and a steady-state error brought by power coupling can be eliminated.

Description

Technical field: [0001] The invention belongs to the field of virtual synchronous motor control, and in particular relates to a power decoupling method of a virtual synchronous generator based on current compensation. Background technique: [0002] Renewable new energy power generation mainly based on wind power and photovoltaics mainly uses power electronic converters as grid-connected interfaces, which have the advantages of flexible control and quick response, but also have shortcomings such as lack of inertia and damping, especially at present Current converters are often connected to the grid in current source mode, which is significantly different from the synchronous generators used in traditional energy sources in terms of external characteristics. Now, with the continuous improvement of the penetration rate of distributed renewable energy, the rotating reserve capacity and moment of inertia in the power system are relatively reduced, which increases the frequency fl...

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Problems solved by technology

[0005] The purpose of the present invention is to provide a virtual synchronous generator power decoupling method based on current compensation for the defect that the existing virtual synchronous motor technology cannot be accurately decoupled

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