Abstract: A mathematical model of direct-drive permanent magnet wind power system was built,which includes wind turbine model,drive train model,permanent magnet synchronous generator model and converter model as well.According to the maximum wind tracking principle,control strategies of converters at generator and power grid sides were put forward.The simulation model of the wind power system was built in Matlab/Simulink software environment,and the case of wind speed stepping change was simulated.The simulation result verified the validity of the control stratesy and the feasibility of the model.