Control Of Energy Storage Power Plant Participating In Grid Primary Frequency Regulation Strategy Research

In the new power system with new energy as the main part,with the increasing proportion of new energy,the disturbance of the system becomes more and more frequent,while the resources for peak and frequency regulation become more and more scarce,and the safe and stable operation of the power system and power quality are facing great challenges.With the advantages of fast response,bi-directional throughput and easy precision control,battery energy storage can respond to dispatching commands for peaking and also use the remaining capacity of peaking for primary frequency regulation,which will play an important role in the operation control of new power systems.This paper studies the control problem of battery energy storage participation in primary frequency regulation and proposes a control strategy of primary frequency regulation with energy storage units in energy storage power plants as the basic control object.Specific work includes:Firstly,this paper introduces the main research content of this paper by analyzing the current status of energy storage participation in grid frequency regulation and the problems of control strategy;based on the principle and characteristics of primary frequency regulation of traditional units and energy storage power plants,the equivalent models of primary frequency regulation of traditional units and energy storage power plants are established respectively;the regional equivalent model of primary frequency regulation of power system containing energy storage power plants is established by analyzing the demand of primary frequency regulation output of energy storage power plants and the demand of State of Charge restoration of energy storage.Secondly,the participation factor of energy storage unit is defined,and the basic control object is energy storage unit,and the share of frequency modulation output of each energy storage unit is dynamically allocated according to the deviation of system frequency from rated value,speed and participation factor of energy storage unit,and three control methods of virtual positive/negative inertia and virtual sag are coordinated to control the output of energy storage unit with Logistic function,which not only takes into account the SOC and frequency modulation output of each energy storage unit,but also improves the primary frequency modulation effect.SOC and frequency modulation output of each storage unit,and improve the effect of primary frequency regulation.Subsequently,based on the ultra-short-term load forecast,the target value of SOC prerecovery for each energy storage unit during the non-frequency regulation period is calculated;by considering the recovery demand of energy storage unit SOC and the redundancy capacity of the power system to withstand load fluctuations,the SOC prerecovery expectation coefficient and limitation coefficient are set;on this basis,the energy storage unit SOC pre-recovery control strategy is proposed,which not only improves the utilization rate of the energy storage unit frequency regulation capacity,but also effectively responds to the system load fluctuations in the next phase.Finally,a regional equivalent model of the primary frequency regulation of the grid with energy storage power plant is built under the MATLAB/Simulink simulation platform,and the effectiveness and advantages of the control strategy proposed in this paper compared with the conventional control strategy are verified by applying the control variable method simulation.