Research On Control Strategy And Energy Storage Capacity Allocation Of Combined Frequency Modulation Of Wind Storage

With the rapid development of wind power technology and the proposal of sustainable development strategies such as carbon neutralization and carbon peaking,the permeability of wind energy as a major new energy in the power system is gradually increasing.Large-scale wind power grid connection will cause the inertia of the power system to decrease,intensify the frequency modulation pressure of traditional generator sets,and reduce the frequency stability of the power system.How to improve the frequency response ability of high wind power permeability system has become an urgent problem to be solved.Therefore,this paper studies the participation of wind power and energy storage in primary frequency modulation.In this paper,the basic principle and traditional control mode of wind power’s participation in primary frequency modulation of power system are analyzed firstly,and the relevant model is constructed,and the frequency response characteristics of wind power participation in primary frequency modulation under full wind speed are simulated and analyzed.On this basis,the model of wind power + hybrid energy storage system including doubly-fed fan,super capacitor and battery is established.Aiming at the problem of cooperative primary frequency modulation control strategy for wind power + hybrid energy storage system,a cooperative frequency modulation control strategy based on double-layer optimization is proposed.Firstly,the operation status of the air storage and SOC monitoring feedback are realized through the outer control,and the frequency modulation power instruction is allocated to the fan and the hybrid energy storage to realize the coordination of frequency modulation power instruction allocation.Secondly,the primary frequency modulation control mode of DFIG combined with rotor kinetic energy control and load reduction control is designed in the inner layer to explore the frequency modulation potential of wind turbines.At the same time,at the level of primary frequency modulation control of hybrid energy storage,the dynamic sagging coefficient frequency modulation control based on SOC is proposed,which solves the problem of energy storage overcharging and overdischarging when the traditional fixed sagging coefficient is controlled,and gives full play to the ability of power-type energy storage supercapacitor to adjust high frequency fluctuations and energy-type energy storage battery to adjust low frequency fluctuations.The effectiveness of the proposed strategy in primary frequency modulation is verified by SIMULINK simulation.Aiming at the energy storage capacity allocation problem of wind power +hybrid energy storage frequency modulation,a hybrid energy storage capacity allocation model with the minimum frequency deviation of primary frequency modulation and the lowest annual cost of hybrid energy storage participating system was established.By analyzing the basic principle of traditional NSGA-Ⅱ algorithm,the improved NSGA-Ⅱ algorithm is proposed to solve the energy storage capacity configuration.The simulation and comparison show that the improved algorithm has obvious improvement in the convergence and distribution of solution set.At the same time,according to the five groups of solution sets selected by the Pareto edge of the improved NSGA-Ⅱ algorithm,energy storage is rationally allocated,and different energy storage configuration schemes and frequency responses based on optimal primary frequency modulation,optimal economic cost and optimal comprehensive conditions are analyzed.In order to compare the advantages of single battery energy storage in frequency modulation performance and economy,the economic cost and frequency modulation performance of single battery wind storage system participating in primary frequency modulation are simulated and analyzed,and the good effect of wind power + hybrid energy storage in primary frequency modulation is verified.It not only maintains the frequency stability of power grid,but also reduces the cost of energy storage construction,operation and maintenance of power system.Improved economy.