Research on Active Current Suppression Control Strategy of Photovoltaic Generation System

With the proportion of DC-connected photovoltaic (PV) power supply to the power supply capacity of the grid is increasing, its impact on the grid is also gradually increasing. In this paper, inter-pole short circuit fault and pole-to-ground short circuit fault of the PV generation system in the micro-grid are studied. Firstly, the inter-pole and monopolar short circuit fault characteristics in the DC micro-grid are analyzed. Secondly, the fault state detection method is improved by combining the fault characteristics. It is proposed to control the power electronic element IGBT in the converter to keep it on during faults, so as to shunt the current provided by PV cell, and finally achieve the purpose of suppressor the fault current. The proposed scheme is verified, and the simulation results prove that the control strategy can effectively suppress the fault current of the PV generation system.