Research On Control Of Energy Storage System And Parameter Optimization For Suppressing Electromechanical Disturbance In Power Systems

With the expanding of the power system,the regional power grid gradually gathered into a whole,and sometimes the disturbance in power system just affect the power quality,but sometimes it will cause a breakdown of the power system.Disturbances seriously affect the safe and stable operation of power system.The energy storage system,as a device that can dispatch some active and reactive power,it can assist the system to suppress disturbance and frequency modulation.Now energy storage equipments have gradually entered the power system.First,the paper summarizes the propagation law of electromechanical disturbance in power system.By analyzing the electromechanical disturbance propagation equation of chain system,the transfer function matrix model is modeled,and the G function that represents the dynamic characteristics of the power grid is applied to deal with the line branch in the power grid.For the delay characteristics of electromechanical disturbance propagation,a method is proposed for the ideal uniform chain power system,according to the law of disturbance propagation,which can guide the early-start of energy storage system and restrain the disturbance.Finally,the effectiveness of the electromechanical disturbance propagation model based on the transfer matrix is verified by the simulation of 3 machine 9 node,and the feasibility of the energy storage equipments early-start method is achieved by simulation of uniform chain system.Then,the feasibility of early start method of energy storage equipments has been studied in previous.It has been verified that when energy storage equipments early-start,it could suppressing the disturbance in the ideal uniform chain system.The further research is done on how to apply the energy storage early-start method to the actual power system not idea situation in the previous.According to the oscillation energy theory,the oscillating energy from the bus flow to the branch is derived,and a superconducting magnetic energy storage damping control strategy based on the oscillation energy theory is designed.Considering the energy storage equipments early-start method need disturbance to transmit a certain time.In order to avoid long duration of the disturbance cannot obtain the complete disturbance data in the process of disturbance,considering the actual situation,We should focus the early start method of the research on the early stage of the disturbance to reduce the fluctuation amplitude when the disturbance arrives and reducing the subsequent oscillation energy.The disturbance is suppressed as much as possible in energy storage equipments early-start method and damping control strategy based on the oscillating energy theory.Because of the slow response and low ramp rate of conventional frequency regulation power supply,it has not fully met the problems of rapid development of power system and new energy access.For this problems,the paper research on the battery energy storage system to auxiliary power system frequency regulation.Aiming at the problem of how to coordinate and harmonize energy storage equipments parameters in different regions,a parameter optimization algorithm combined with analytic hierarchy process(AHP)and genetic algorithm(GA)is constructed.Using the analytic hierarchy process,a region frequency regulation hierarchical model is modeled,and the judgement matrix is constructed,and the weight coefficients of the frequency regulation requirements in each area are constructed by hierarchy sorting and consistency checking.So that the frequency regulation requirement is digitalized,and add weight coefficients to the fitness function in the genetic algorithm to optimize the parameters.The simulation results show that compared with the traditional ITAE parameter optimization method,the AHP/GA optimization method can both meet the requirements of different region frequency regulation and parameters optimization.