Abstract: Aiming at the different requirements of photovoltaic system short-circuit current analysis in terms of simulation analysis accuracy, calculation speed and other aspects under different scenarios, three photovoltaic system short-circuit current calculation models suitable for accurate simulation, small-scale distribution system simulation, and large-scale distribution system engineering calculation are proposed.Firstly, device level short-circuit transient model of photovoltaic system is proposed, in which the device level main circuit and complete control algorithm are adopted. On this basis, short-circuit low-frequency transient equivalent model of photovoltaic system is proposed and the main circuit and control algorithm are simplified with retaining the low-frequency transient characteristics. Based on the equivalent model,phase-locked loop is removed and its mathematical model is deduced, which is further simplified to calculate only the steady-state effective value and sub transient peak value of short-circuit current. Finally,the power flow calculation software written under MATLAB are done. The simulation results are compared to verify the effectiveness of the three types proposed models of photovoltaic system.