摘要
为平抑分钟级的功率波动,使风电功率满足并网标准,基于小波分析提出功率分配数动态变化的混合储能系统(hybrid energy storage system,HESS)控制策略。设计了功率分配数根据风电功率超短期预测结果和HESS的荷电状态(state of charge,SOC)动态调整的分频方法,从而改变并网的低频目标功率和需要蓄电池、超级电容平抑的中、高频功率;建立兼顾HESS控制成本、功率平滑度的多目标优化函数,并应用改进的NSGA-Ⅱ算法对功率分配数进行滚动优化,从而达到最优控制;针对基本NSGA-Ⅱ算法在维持种群多样性、均匀性上的不足,以及种群规模大的问题,对精英保留策略进行了改进。最后,通过美国某州风电场实际观测数据进行实例验证,结果表明,所提控制策略能充分发挥不同类型储能的优势,经济、快速地平抑风电功率波动。
To smooth minute-level wind power fluctuation and make wind power satisfy the grid standard, this paper proposes a control strategy of hybrid energy storage system （ HESS ） with the power allotment levels adjusting dynamically based on wavelet analysis. And this paper designs a method of frequency division that the pwer allotment levels adjust according to the result of wind power short-term prediction and the state of charge （SOC） of HESS, which can change the low-frequency target power into power grid, as well as the middle and high frequency power absorbed by battery and super capacitor respectively. Then, this paper establishes a multi-objective optimization function considering the control cost and smoothness of HESS, and applies improved NSGA- II algorithm to achieve rolling optimization, calculate the optimal power allotment levels and obtain the optimal control strategy. This paper improves elitism strategy to overcome the shortage of basic NSGA-II algorithm in maintaining population diversity, the lack of uniformity and large population size problem. Finally, case studies through the actual observation data of a wind farm in the United States demonstrate that the proposed control strategy takes advantage of different types of energy storage and smooths the fluctuation quickly and economically.
出处
《电力建设》
北大核心
2017年第9期111-119,共9页
Electric Power Construction
基金
四川省科技计划项目(2015JY0128)
