Wind Active Power Control Of The System Frequency Response

At present, new energy power generation is in the promotion stage, and wind power penetration is increasing gradually. Large-scale wind power connected to grid will make the system frequency regulation more difficult. However, the variable speed constant frequency wind turbine is isolated from the grid by the power electronic device, which cannot response the frequency of the system as a conventional synchronous machine. Wind turbines should be involved in the system frequency regulation, when connected to the grid on a large-scale. Therefore, it’s necessary to carry out the research of wind active power control of the system frequency response.This paper presents a directly driven wind turbine with permanent synchronous generator (D-PMSG) control strategy of wind active power control to response the system frequency below rated wind speed, and put forward the improvement wind power control method. Power-frequency curve is determined by the actual characteristics, i.e. a corresponding relation between the rotor speed and the captured wind power by the prime mover. Rotor’s given speed is determined by the wind turbine output power, and controlled by the three-phase PWM rectifier. Reactive power is controlled by the d-axis current. Actual output power of wind is sent to the grid, through the grid inverter connected to the electricity grid.Under the principle of the energy management, energy storage devices can absorb redundant power and release the power shortage, which makes the output wind power have inherent power-frequency characteristics, and have the ability to response the change of system frequency.This paper built D-PMSG’s active power control to response the system frequency with Matlab/Simulink software, and operated the simulation experiment with the corresponding control method. The simulation results validated the rationality of the active power control strategy, which provided a theoretical support for the large-scale wind power integration. Physical experiment proved the effectiveness of active power control with the energy storage devices.