基于二阶VSG的变换器频率支撑能力评估及提升方法OA北大核心CSTPCD

As the penetration of wind and solar energy generators increases,traditional synchronous generators are being replaced,and their support functions must be implemented using renewable generators.Grid-forming technologies enable renewable generators to support power systems.Focusing on the characteristics of the response process of a grid-forming converter under unbalanced active power disturbances and the limitations in assessing its support capabilities,this paper proposes a method to evaluate the frequency support capability of grid-forming converters by applying a unified motion equation model and optimizing the frequency support functionality.Since the grid-forming converter has a relatively slow primary frequency regulation characteristic,a second-order virtual synchronous generator was designed to improve frequency dynamics using virtual inertia and damping coefficients.Time-domain simulations conducted in MATLAB/Simulink verified that the second-order virtual synchronous generator enhances the frequency support capability of grid-forming converters and system frequency dynamics.