Virtual Admittance Control Strategy of Grid-Connected Converters for DC Voltage Ripple Suppression

The low-voltage new energy system with high proportion of power electronic equipment are at risk of oscillation, and the oscillation and ripple of the DC bus voltage show wide-band characteristics. In order to solve this problem effectively, a virtual admittance control strategy of grid-connected converter(GCC) for DC voltage ripple suppression is proposed. By detecting and extracting ripple information, the method automatically adjusts the operating frequency band of virtual admittance according to the ripple frequency. This method reshapes the output impedance of DC side of GCC to absorb ripple current, thereby enhancing the system's ability to suppress DC voltage ripple. Simulation results show that the proposed method can suppress the wide-band ripple of DC voltage well and maintain system stability.