Fuzzy-Adaptive Frequency Control of Power System Including Microgrids, Wind Farms, and Conventional Power Plants

In this paper, the effect of the increased penetration of wind farms (WFs) and microgrids (MGs) on the frequency control of power systems is studied. WFs are responsible to contribute in load frequency control of power system by changing their injected electrical power. A new control method is proposed to utilize the kinetic energy of wind turbines to support system frequency, considering minimum speed of their rotor. Also, distributed energy resources of MGs, in each area, are controlled to change their active power and adjust the injected power at point of common coupling after a disturbance in the power system. A modified hierarchical coordinated control is used for the optimal control of the entire system. In the first level of this hierarchical control system, each area is optimized and in the second level (coordinator), interactions between areas are adjusted for the global optimization. The parameters of the controller are adaptively adjusted by a fuzzy controller for the best performance in different operating conditions. It is shown that using the proposed control system, the frequency deviations of the power system will decrease.