Frequency Control Of The Power System With High Penetration Of Wind Generation

In the power system with high penetration of wind generation, the fluctuating power and weak inertia of the wind generation bring challenges to the frequency control of the power system. By making researches over different levels of the power system, such as wind turbines, wind farms, energy storages and the control and operation of the power system, this work aims to obtain the solutions to improve the frequency control of the power system with high penetration of wind generation.For the fluctuating power of wind generation:at first, the impacts from the wind power fluctuations to the frequency control and operation adequacy of the power system are investigated separately over the two time scales of from minute to several minutes and from several minutes to30minutes; then, the energy storage demand reduction based solutions to determine the two time-scales wind power fluctuations mitigation targets are proposed to support the planning and operation of the demonstration project; furthermore, a coordinational control method for the batteries energy storage system (BESS) to mitigate the wind power fluctuations is proposed, which could achieve the two time-scales mitigation targets and reduce the demand of power and capacity of the BESS.For the weak inertia of wind generation:at first, a wind speed adaptive control method for variable speed wind turbines (VSWTs) is proposed, which enables the wind turbines to offer temporary and stable frequency support over varying wind speed and large wind speed range; then, based on the analysis on the capabilities and energy cost of the VSWTs to support frequency regulation, an optimal control method for VSWTs based wind farms to temporarily support frequency control is proposed, which is dispatch support power orders to the VSWTs which are under different wind speeds, reduce the energy cost of the whole wind farm, and improve the frequency control performance of the power system; finally, the effectiveness of whole control method is verified in the IEEE reliability test system (IEEE RTS), and compared with the existing methods.