Maximum power point tracking for a PMSG based variable speed wind energy conversion system using optimal torque control

Abstract

Wind Energy is the most widely used non-conventional, renewable energy source. The rapid technological advancement in field of Wind Energy Conversion Systems (WECS) has led to a number of environmental, social and economic benefits. When compared with Constant-speed WECS, Variable-speed WECS provides lot of advantages, which includes an increase in power output, reduction in mechanical stress and an improvement in power quality and system efficiency. In recent years, many Maximum Power Pointing Tracking (MPPT) techniques have been developed for variable speed operation of the Wind Energy Conversion Systems to maximize the power extraction. In this paper for a PMSG based WECS, Optimal Torque Control (OTC) method is used to track the maximum power point. The whole system has been simulated using PSIM software. The Optimal Torque Control is achieved in PMSG by using Zero Direct-Axis Current (ZDC) control. A back to back converter has been connected to the PMSG to convert the variable voltage, variable frequency input to a constant voltage, constant frequency output. The output voltage is maintained at 60V while output frequency is maintained at 50 Hz.