Research on short-circuit fault characteristics of direct-drive permanent magnet wind turbine

The network structure and short-circuit capacity are changed after large-scale wind power integration, which will affect the configuration and setting calculations of system relay protection, therefore, an accurate assessment of short-circuit current level are required for the power system with wind power integrated. In this paper, power system model including wind farms was built in MATLAB/SIMULINK, and short-circuit current characteristics of direct-drive permanent magnet wind turbine was simulated and studied. The simulation results show that direct-drive permanent magnet wind turbine can provide continuous short-circuit current to the power grid when permanent power failure occurred, and the external characteristics of the short-circuit current is related to the control mode of inverter. The research result provide theoretical basis and decision support for short-circuit calculations and relay protection setting of power network with large-scale wind power system.