Study On Control Strategy And Performance Evaluation Standard Of Primary Frequency Regulation Of Electric Energy Storage

With the increasing development of UHV ac/dc power grid and the integration of large-scale wind power,photovoltaic and other clean energy,the system frequency response capacity is reduced,andthe development of power system frequency regulation(FR)is unbalanced at both ends of the "attack and defense".Therefore,the system FR auxiliary service is in urgent need of new FR means.Battery energy storage has such excellent characteristics as rapid response,high control accuracy and bidirectional regulation,etc.,so it has great potential as a new FR means.For the electric energy storage system to participate in the system operation control,it is necessary to design an appropriate control strategy and its control performance evaluation standard,so that not only it can give full play to its excellent performance in a frequency adjustment,but also ensure its control behavior is optimized enough to maximize its benefits in the whole life cycle.Through the comparative analysis of the existing energy storage technologies,the technical and economic advantages of the electric energy storage system participating in primary frequency regulation(PFR)are clarified.A comprehensive model of battery energy storage system for grid frequency regulation is constructed.An improved control strategy with consideration of FR and economic benefits was designed,and hooke-jeeves direct search algorithm was used to set the control parameters.Based on the proposed standard design idea,a control performance evaluation method for the electrical energy storage system participating in PFR is designed based on the probability and statistics theory,which can not only accurately identify the fast regulation behavior of frequency response,so as to guide them to actively participate in the system operation control and maintain the safety and stability of the system operation,but also takes into account the maintenance of the charged state of the energy storage system,so as to guarantee the economic benefits of the energy storage system.Using the historical data of a power grid operation frequency and MATLAB as the experimental platform,the designed control strategy and evaluation standard are simulated and analyzed by using the single region simulation system with BESS.The results show that:the proposed control strategy can not only achieve good frequency modulation effect,but also effectively reduce the battery aging rate;The capacity attenuation rate decreases with the increase of the configured capacity,and the FP effect increases with the increase of the configured capacity;The proposed performance criterion can accurately evaluate the control performance of the electrical energy storage system participating in PFR,and clearly distinguish the different capability input level and response delay time of the electrical energy storage system;the evaluation criterion of input can clearly distinguish the unit input.With the establishment and improvement of the market mechanism of energy storage auxiliary FM service in China,relevant work can provide reference for the energy storage system to participate in the operation and control of frequency response service,which has good referencevalue for theoretical research and engineering practical.