Maximum power extraction for direct driven variable speed wind turbine system using PMSG and fixed pitch angle

This paper proposes a simple technique to extract maximum power at a particular wind speed of a wind energy conversion system (WECS). This system uses permanent magnet synchronous generator (PMSG), uncontrolled rectifier, DC-DC boost converter and a resistive load. It utilizes the DC current and DC voltage obtained after rectification to calculate DC power and to control the duty cycle of the DC-DC boost converter to obtain maximum power point tracking (MPPT). From the measurement of DC current and voltage, maximum DC power can be tracked and optimum value of power coefficient of wind turbine (Cp) can be reached. The advantage of proposed system is that no prior knowledge of wind speed characteristics as well as wind generator optimal power characteristics is required. This system uses fixed pitch angle.