Maximum power point tracking strategy and direct torque control of permanent magnet synchronous generator wind farm

A wind farm with variable speed wind turbines usually consists of a large number of Wind Turbine Generators (WTGs) connected and operating simultaneously. The study of a wind farm with Permanent Magnet Synchronous Generators (PMSG) is presented. The 30 KW wind farm consists of 3 PMSGs based 10KW generators connected to a common DC-bus. Each PMSG of the wind farm is connected to the DC-bus through a rectifier, but the DC-bus is connected to the grid through only one DC/AC inverter. The proposed control strategy is introduced aiming in both Maximum Power Point Tracking (MPPT) control method and Direct Torque Control (DTC). The PMSG side converters are used to achieve MPPT. The reference speeds of the generators are dynamically modified according to the wind speeds so as to maintain the wind turbines at maximum power operating point. The grid-side converter regulates DC-link voltage and injects the generated power into the AC network. Direct power control of PWM inverter is adopted. Grid-side reactive and active power decoupling method is applied to regulate the grid-side power factor. Simulation results confirm that the proposed strategy has excellent performance.