Dynamic Droop Control for Wind Turbines Participating in Primary Frequency Regulation in Microgrids

Abstract

Wind power will provide a significant portion of electricity generation in the near future. This significant role requires wind power generators to contribute to the system frequency regulation. The droop method is one of the most popular methods to be implemented in these generators to mimic the governors of conventional generators and contribute to both transient and steady-state frequency regulation. However, the unpredictability of the variable wind speed complicates this implementation. In the present wind-based droop methods, the maximum allowable droop gain is a function of the wind speed. This dependency means either that the entire available capacity of the wind generator will not be used or that instability will threaten the implemented droop wind generators. This paper proposes the efficiency droop, a new droop-based method, which can be tuned regardless of the wind speed. Small-signal analyses are used to study the method in depth and compare its influences on both the transient and steady-state frequency performance to the influence of the present methods while adopting minimum approximation. Detailed time domain analyses are used to verify the analytical results.