Research On Control Strategy Of Hybrid Energy Storage System Based On Wind Power

In order to achieve the goals of "carbon peak" and "carbon neutrality",and solve the problems of fossil energy depletion and serious environmental pollution,vigorously developing new energy power generation is a practical and effective way.However,the inherent randomness and weak frequency modulation capability of renewable energy power generation will bring new challenges to traditional power systems.The use of hybrid energy storage systems is a feasible way to solve this problem.This paper takes the power smoothing and frequency modulation ability of renewable energy as the research object.By introducing a hybrid energy storage system composed of batteries and supercapacitors,the control strategy of the hybrid energy storage system is studied to reduce the power fluctuation of the new energy and participate in the primary frequency modulation of the power system.In addition,the control parameters in the control strategy are very important to the control effect.In this paper,an intelligent algorithm is used to optimize the control parameters.Through simulation analysis and comparison with other control strategies,the advantages and effectiveness of the proposed strategy in the aspects of power fluctuation suppression and auxiliary frequency modulation are verified.Firstly,the working characteristics and maximum power tracking control principle of wind power generation,which is the most representative in renewable energy generation,are studied,and the working principle and common simulation models of batteries and supercapacitors are analyzed.And simulation models are built on the basis of the analysis,which provides a research foundation for the subsequent research and verification of hybrid energy storage control strategies.Secondly,a comprehensive control strategy based on the hybrid energy storage system that can simultaneously stabilize wind power fluctuations and participate in the primary frequency modulation is proposed.The control strategy includes two parts:the power fluctuation suppression control and the auxiliary frequency modulation control.Among them,the power fluctuation suppression control part comprehensively considers the fluctuation requirements of the grid-connected wind power,the system frequency,the real-time state of charge of the battery energy storage and other factors to adjust the filter time constant,and adaptively reduces the adverse effects of the volatility of the wind power generation on the frequency of the power system.The auxiliary frequency modulation control part imitates the droop characteristics and inertia links of conventional units,which can improve the primary frequency modulation capability of wind power generation.And compared with other control strategies through simulation analysis,the superiority and effectiveness of the proposed strategy in suppressing power fluctuations and auxiliary frequency modulation are verified.Finally,the optimization of the control parameters in the control strategy is studied,and an improved root tree algorithm is proposed on the basis of the traditional root tree algorithm to optimize the control parameters in the control strategy.By adaptively adjusting the proportions of the three different roots according to the location of the optimal roots in each iteration of the calculation,it is solved that the traditional root tree optimization algorithm needs to be changed multiple times for optimization calculations to determine the optimal proportion in order to obtain the best optimization effect.And based on the hybrid energy storage control strategy proposed in this paper,the optimization effect and improvement effect of the improved root tree optimization algorithm are verified.