Optimization of the DFIG Wind Turbine Controller Parameters by the Gray Wolf Algorithm

The increase in the power generated by the wind has had effects on the performance of the power system in cases such as power quality, safety, stability, and voltage control. The wind turbines are used to generate electrical energy from wind. They can work in fixed or variable speeds. The asynchronous generator is directly connected to the grid for the fixed-speed wind turbines. In order to connect the DFIG (Doubly-Fed Induction Generator) to the grid, this machine must be able to integrate its generated power into the grid in a specific voltage (the grid voltage level). The main DFIG controlling method is the use of field-oriented vector control for regulating the rotor flux. The DFIG vector control consists of two main parts as grid side converter control and rotor side converter control. The rotor side converter is used to control the grid output power. This converter regulates the power factors in the terminals, and actually restores the generated power deviation from the reference power through the PID controllers, besides guaranteeing the stability of the induction generator. In the current study, the power was controlled through the determination of the PID optimal coefficient of the rotor and grid sides controllers and the gray wolf algorithm in the MATLAB software. In addition, the stability of the small signal of the grid equipped with the doubly-fed wind generator in the wind speed turbulence conditions was optimized to satisfy the required criteria in output active and reactive power of a DFIG. From the simulation results it is observed that the proposed controller yields better results when compared to other methods in literature in terms of performance index.