H ∞ Robust Frequency Control of Wind Turbine Generators and Electric Vehicles in Isolated grid

Abstract

Wind turbine generators (WTGs) occupy an increasingly larger share in power system. WTGs in isolated grid lead to fluctuation in power and decrease system inertia. To reduce frequency deviation due to power fluctuation or wind speed change, model of WTGs is established based on deloading control. Considering that WTGs will have institutional wear because of frequent frequency regulation, which would short the life of WTGs, a robust frequency control strategy is proposed. WTGs and electric vehicles (EVs) are used in this control strategy. To suppress disturbances due to wind speed and uncertainty of system parameters, a H ∞ robust controller is solved using linear matrix inequality (LMI) methodology. Time-domain simulation results shows that the adopted control methodology can decrease frequency deviation during power fluctuations and wind speed changes.