A control strategy of direct driven permanent magnet synchronous generator for maximum power point tracking in wind turbine application

A novel maximum power point tracking (MPPT) strategy is presented in the paper. When wind speed varies, the wind turbine could obtain a big torque difference by adopting the novel strategy to achieve the aim of tracking the optimum turbine speed fleetly. The square wave permanent magnet synchronous generator (PMSG) is adopted in this paper for considering the characteristic of the diode rectifier-Boost circuit-voltage source inverter power transformation structure. The DC-link capacitor voltage is maintained at a constant value by ensuring the balance of the input and output energy of the both sides of the capacitor. The independent control of boost circuit and inverter is achieved. The simulation results indicates that compared with the conventional MPPT strategy, the efficiency of the turbine capturing wind energy by adopting the novel MPPT strategy is enhanced. And the independent electric control mode not only ensures the stability of generation system operation but also strengthen the flexibility and compatibility of system control.