Research On The Control Strategy And Capacity Configuration Of Pumped Storage-Flywheel Energy Storage Participating Frequency Regulation

In recent years,the penetration of new energy resources have increased year by year,and its inherent randomness and volatility have brought challenges to the frequency security of power grid.However,due to the long response time and low ramp rate,the conventional frequency regulation resources cannot fully meet the requirements of frequency regulation,and in this context,various types of energy storage technologies have been rapidly developed.Pumped storage,as one of the most widely used energy storage technologies in China,has good potential in frequency regulation in addition to its excellent peak shaving and black start ability.In order to solve the problems such as long response time and bad frequency regulation performance caused by the inherent vibration zone when pumped storage is used as the main frequency-control plant,it is considered to use the flywheel energy storage as the supplement to improve the short-term regulation capacity of pumped storage.Focusing on the problem that pumped storage-flywheel energy storage participating in frequency regulation of power grid,this paper studies model establishment,control strategy and capacity configuration of pumped storage and flywheel energy storage.Firstly,based on the frequency regulation principle of power system,the load frequency control element model is established,and then the load frequency control model of single region and two regions are built.Based on the analysis of the operating characteristics of pumped storage,a two-zone load frequency control model with two operating conditions of pumped storage is established,and these models are tested by simulation.Then,the necessity and feasibility of flywheel energy storage participating in frequency regulation with pumped storage are analyzed.Based on improved grey prediction model and fuzzy control,this paper designs a power allocation correction strategy and a flywheel output control module which contains flywheel power constraint and self-recovery mode to ensure that flywheel can operates in a healthy and efficient way.The simulation results show that the proposed scheme and strategy have advantages in improving the system frequency regulation ability,improving the utilization rate of the hybrid energy storage system and improving the maintenance effect of the flywheel’s state of charge.Finally,the life cycle cost-benefit model of pumped storage-flywheel storage is established.On this basis,an analysis model of influencing factors of hybrid energy storage configuration considering the benefits of frequency regualtion,peak regulation and wind power consumption was established.With the goal of economy,the influences of various parameters on the capacity configuration under various application scenarios were analyzed.The configuration results showed as follows:The results of flywheel energy storage configuration were strongly correlated with parameters of frequency regulation,and the results of pumped storage configuration were strongly correlated with wind power installed capacity and load peak-valley difference and so on.Based on the analysis results of the influencing factors,a hierarchical capacity allocation model of pumped storage and flywheel was established.Pumped storage capacity configuration layer takes the investment cost,wind power acceptance and the peak shaving effect as the optimization function,and flywheel energy storage configuration layer takes the investment cost and the frequency regulation effect as the optimization function.The flywheel capacity allocation layer was solved by using the improved quantum particle swarm optimization algorithm based on hunting behavior.The analysis verifies the rationality of the configuration scheme in this paper.