Abstract: With the proposal of the "emission peak and carbon neutrality" goals and the rapid development and widespread application of PV power generation technology,PV power has become the main force in the integration of new energy into the grid. However,the control strategies of PV power systems differ from those of traditional thermal power generation systems.When faults occur in the transmission lines,the electrical characteristics under its control strategy are distinct from those of traditional synchronous generators. Therefore,studying the impact of the control strategies of PV power generation systems on their fault characteristics is of significant importance. A mathematical model of the PV power generation system based on the dq coordinate system is established in this paper,and the design of control strategies and their application effects under various fault conditions are studied in depth. Through theoretical analysis and simulation experiments,the performance of the PV power generation system during faults period is comprehensively analyzed from multiple perspectives,including amplitude,phase,and sequence components. The research results show that the control strategies of PV power generation systems can effectively adjust the electrical characteristics of fault current to meet the stability requirements of the power grid.