Variation Rule of Wind Speed and Its Influence on the Fast Frequency Response of Wind Turbine Generator

Abstract

The equivalent inertia of the power system has been significantly reduced with the massive adoption of new energy generation and equipment with power electronic interfaces. Many countries require wind power generation to be capable of offering a fast frequency response (FFR) when deviations in power system frequency occur. Because the FFR covers a short duration, the wind speed variation during this period has been largely ignored in previous studies. In this paper, we paid attention to the wind speed variation rule within a 15 s time frame. By analyzing the measured data of a wind farm, we found that the wind speed variation rule within 15 s can be clustered into six categories, among which the probabilities of continuously rising wind speed and continuously falling wind speed are the two with the largest values, 37.68%, and 37.49%, respectively. The change of wind power in the 15 s time range usually does not exceed 40%. Subsequently, we analyzed how the various wind speeds affect the FFR of the wind turbine generator (WTG) with combined virtual inertia and droop control. The simulation results suggest that there is little difference in the WTG response within the first 3 s of the FFR whether the wind speed change is considered or not. However, there is a significant difference in the response of the WTG with or without considering the wind speed variation in the subsequent time. Therefore, to study the FFR control of the WTG or to accurately evaluate the effect of the FFR, the wind speed variation should be considered.