A rotor speed estimation algorithm in a direct vector controlled permanent magnet synchronous generator wind energy conversion system is proposed. The method is based on a simple equation obtainer from stator voltage and current. Stator flux information required by the speed estimator is obtained using the stator voltage equation by implementing a programmable low pass filter. The constant gain recursive least squares algorithm is adopted. Then, the rotor position obtained based on the proposed method are used in the rotor-flux oriented vector control of PMSG. The simulation result shows that the control strategy realizes maximum power point tracking control, which verifies the validity and feasibility of the theoretical model and control strategy.