Research On Automatic Generation Control Of Power System With Wind Power Using Energy Storage

Wind power come with great fluctuation and uncertainties, and their penetration into power system has brought great challenges to the security and stability of the grid. Meanwhile, the slow reaction and low ramping rate of traditional generations fail to meet the needs of power system's fast development and absorb new energy. As a result, to safeguard frequency stability of power system in high permeability of wind power's generation is one of the new challenges for Chinese grid.In recent years, the rapid advancement of energy storage technologies has shed a new light on the solutions of these issues. Energy storage system (ESS) possesses the ability to track power accurately with nearly no delay, which makes it capable of providing frequency regulation services of high quality. Therefore, with a consideration of the technical characteristics of ESS, it is of great theoretical and practical importance to research on control strategies for ESS to participate in power system ancillary services. It can provide references for the stable operation of power system and improve the ability to integrate renewable energy into the system.The paper first introduced the basic mechanism and conception of frequency regulation(FM) in power system; clarified the specific methods to achieve various levels of FM, and AGC is used in secondary frequency regulation, and the way of management and control of ESS participating in AGC of power system with renewable energy was studied.The wind power fluctuation character described by t-location model was described, the time series of wind power by the sequential of Monte Carlo was created, and the impact of wind power fluctuation on the frequency of power system has been simulated based on a regional power system.As for AGC, flywheel energy storage system with fast and accurate power tracking ability is chosen to provide regulation service. Probability statistics methods were used to make quantitative analysis of the AGC's capacity demand in case study. An economic model of the coordinating system was also established to make an economic evaluation.Acoordinated control strategy for ESS to participate in system AGC, coordinating with the traditional generator was presented. To achieve the coordination among different frequency regulation resources while fully utilizing the advantages of ESS, different response priorities and control strategies are set based on the different operating states. To verify the effectiveness of the proposed control strategy, dynamic simulation for ESS to participate in AGC of a two-area interconnected power system was conducted in the MATLAB/Simulink program. Simulation results show that the proposed method can achieve the coordination between ESS and traditional generator, thus improving regulation effect of frequency and tie-line power exchange deviation and maintaining the SOC of ESS within a desired range, which provides power support under disturbance or fault conditions, improving the operational level of the grid and the ability to withstand the fault.