On maximum power point tracking control strategy for variable speed constant frequency wind power generation

Based on the characteristic of AC-excited variable speed constant frequency (VSCF) wind power generation, the vector control technique was applied in a doubly fed induction generator (DFIG). Maximum wind energy or maximum output power point can be tracked by decoupling control of active power and reactive power. The research result shows that the net power of generation system delivered to grid in maximum wind energy tracking mode is not the most. We presented a novel maximum power point tracking (MPPT) control strategy by analyzing the DFIG mathematic model and power relations which delivered the maximum power to the grid. The maximum power point could be tracked automatically without measuring wind speed in the control strategy and the control was independent of optimal turbine power curve, which had excellent dynamic and static performances and robustness. Simulation and experimental results testify the accuracy and validity of the control strategy.