Hybrid Energy Storage Control with SOC Self-recovery to Smooth out Wind Power Fluctuations
Lin Li1, Lin Yulu1, Tan Huidan1, Jia Yuanqi1,2, Kong Xianyu1, Cao Yapei1
1. State Key Laboratory of Power Transmission Equipment & System Security and New Technology Chongqing University Chongqing 400044 China;
2. State Grid Chongqing Electric Power Company Shinan Power Supply Branch Chongqing 400060 China
The increase in penetration of new energy sources such as wind power poses a huge threat to the security and stability of the power grid operation. This paper used a hybrid energy storage system with a battery and supercapacitor to cope with the complex fluctuations of wind power. To achieve the smoothing of grid-connected power fluctuations while reducing the lifetime losses of the storage system, this paper proposed a hybrid energy storage control method taking into account the state of charge (SOC) self-recovery to smooth out wind power fluctuations, including model predictive control (MPC) to predict the target power of hybrid storages and weighted moving average (WMA) method with fuzzy control to allocate target power.
This paper first established the MPC optimization target function combining SOC recovery for energy storage systems and grid-connected power fluctuation smoothing capability. To characterize the relationship between the SOC and the charge and discharge margin of the energy storage system, a charge and discharge saturation capacity function was proposed. This function was also introduced as a weighting factor into the MPC optimization target function, achieving rapid adjustment of the SOC during power smoothing and improving the long-term stable operation capability of energy storage. An improved WMA method was then proposed to distribute the MPC-predicted target power between supercapacitor and battery power. Considering the small capacity of supercapacitor which is easy to overcharge and over-discharge, the SOC of the supercapacitor at the previous moment and the change of SOC of future hybrid energy storage were taken as fuzzy control inputs. According to the different operating conditions, the fuzzy control rules were designed to dynamically adjust the WMA sliding window length d and the α weighted of past and future reference values, thus improving the adaptability of the battery and supercapacitor to different target power and different SOC.
A wind-storage joint model was developed in MATLAB, and the simulation compared the control effects of three methods of optimization targets. Method 1 is SOC closed to 0.5 at real-time. Method 2 is minimizing the fluctuation rates of grid-connected power. Method 3 is the optimization method for this paper. The simulation results show that the fluctuation rates of grid-connected power are less than 2% by method 3, in which 43.4% of the fluctuation rates are below 0.2%, and the average fluctuation rate is 0.61%, which is between the other two methods. The total charge and discharge energy of the hybrid energy storage is 28.93, which is much lower than the 47.67 of method 2. The average charge and discharge margin of 0.9486 is close to 0.9787 for method 1, but much higher than 0.5914 for method 2. For different initial SOC, the SOC can gradually recover to around 0.5 and eventually follow the change of the control group with the initial value of SOC=0.5. Simulations were then carried out to verify the power allocation strategy with improved WMA-fuzzy control. The results show that the power variation of the battery is relatively gentle compared to that of the supercapacitor, and only varies greatly in the time of 240min to 480min and 720min to 960min when the power demand is high.
The simulation analysis leads to the following conclusions. Firstly, the proposed model predictive control for the target power of hybrid energy storage can effectively smooth out wind power fluctuations, and also effectively optimize the operation interval of SOC and reduce the lifetime loss of energy storage. Secondly, the designed allocation strategy adaptively adjusts the distribution of energy storage power according to the power demand. This strategy reduces the depth of discharge and the charge-to-discharge transition state of the battery at low levels of power output, thus reducing the loss of life. In contrast, increasing the battery output when the power demand is high. It reduces the pressure on the supercapacitor and improves the rationality of the power distribution.
林莉, 林雨露, 谭惠丹, 贾源琦, 孔宪宇, 曹雅裴. 计及SOC自恢复的混合储能平抑风电功率波动控制[J]. 电工技术学报, 0, (): 111-111.
Lin Li, Lin Yulu, Tan Huidan, Jia Yuanqi, Kong Xianyu, Cao Yapei. Hybrid Energy Storage Control with SOC Self-recovery to Smooth out Wind Power Fluctuations. Transactions of China Electrotechnical Society, 0, (): 111-111.
[1] 李军徽, 侯涛, 穆钢, 等. 电力市场环境下考虑风电调度和调频极限的储能优化控制[J]. 电工技术学报, 2021, 36(9): 1791-1804.
Li Junhui, Hou Tao, Mu Gang, et al.Optimal control strategy for energy storage considering wind farm scheduling plan and modulation frequency limitation under electricity market environment[J]. Transactions of China Electrotechnical Society, 2021, 36(9): 1791-1804.
[2] 卓振宇, 张宁, 谢小荣, 等. 高比例可再生能源电力系统关键技术及发展挑战[J]. 电力系统自动化, 2021, 45(9): 171-191.
Zhuo Zhenyu, Zhang Ning, Xie Xiaorong, et al.Key technologies and developing challenges of power system with high proportion of renewable energy[J]. Automation of Electric Power Systems, 2021, 45(9): 171-191.
[3] 周博, 艾小猛, 方家琨, 等. 计及超分辨率风电出力不确定性的连续时间鲁棒机组组合[J]. 电工技术学报, 2021, 36(7): 1456-1467.
Zhou Bo, Ai Xiaomeng, Fang Jiakun, et al.Continuous-time modeling based robust unit commitment considering beyond-the-resolution wind power uncertainty[J]. Transactions of China Electrotechnical Society, 2021, 36(7): 1456-1467.
[4] 杨立滨, 曹阳, 魏韡, 等. 计及风电不确定性和弃风率约束的风电场储能容量配置方法[J]. 电力系统自动化, 2020, 44(16): 45-52.
Yang Libin, Cao Yang, Wei Wei, et al.Configuration method of energy storage for wind farms considering wind power uncertainty and wind curtailment constraint[J]. Automation of Electric Power Systems, 2020, 44(16): 45-52.
[5] Lin Li, Jia Yuanqi, Ma Minghui, et al.Long-term stable operation control method of dual-battery energy storage system for smoothing wind power fluctuations[J]. International Journal of Electrical Power & Energy Systems, 2021, 129: 106878.
[6] 谢小荣, 马宁嘉, 刘威, 等. 新型电力系统中储能应用功能的综述与展望[J]. 中国电机工程学报, 2023, 43(1): 158-169.
Xie Xiaorong, Ma Ningjia, Liu Wei, et al.Functions of energy storage in renewable energy dominated power systems: review and prospect[J]. Proceedings of the CSEE, 2023, 43(1): 158-169.
[7] Wan Can, Qian Weiting, Zhao Changfei, et al.Probabilistic forecasting based sizing and control of hybrid energy storage for wind power smoothing[J]. IEEE Transactions on Sustainable Energy, 2021, 12(4): 1841-1852.
[8] Elmorshedy M F, Elkadeem M R, Kotb K M, et al.Optimal design and energy management of an isolated fully renewable energy system integrating batteries and supercapacitors[J]. Energy Conversion and Management, 2021, 245: 114584.
[9] 齐晓光, 姚福星, 朱天曈, 等. 考虑大规模风电接入的电力系统混合储能容量优化配置[J]. 电力自动化设备, 2021, 41(10): 11-19.
Qi Xiaoguang, Yao Fuxing, Zhu Tiantong, et al.Capacity optimization configuration of hybrid energy storage in power system considering large-scale wind power integration[J]. Electric Power Automation Equipment, 2021, 41(10): 11-19.
[10] Guo Tingting, Liu Youbo, Zhao Junbo, et al.A dynamic wavelet-based robust wind power smoothing approach using hybrid energy storage system[J]. International Journal of Electrical Power & Energy Systems, 2020, 116: 105579.
[11] 万灿, 崔文康, 宋永华. 新能源电力系统概率预测:基本概念与数学原理[J]. 中国电机工程学报, 2021, 41(19): 6493-6509.
Wan Can, Cui Wenkang, Song Yonghua.Probabilistic forecasting for power systems with renewable energy sources: basic concepts and mathematical principles[J]. Proceedings of the CSEE, 2021, 41(19): 6493-6509.
[12] 刘颖明, 王维, 王晓东, 等. 结合风功率预测及储能能量状态的模糊控制策略平滑风电出力[J]. 电网技术, 2019, 43(7): 2535-2543.
Liu Yingming, Wang Wei, Wang Xiaodong, et al.A fuzzy control strategy combined with wind power prediction and energy storage SOE for smoothing wind power output[J]. Power System Technology, 2019, 43(7): 2535-2543.
[13] 何俊强, 师长立, 韦统振. 基于马尔科夫链的自适应储能需求功率预测模型[J]. 电工技术学报, 2021, 36(增刊2): 563-571.
He Junqiang, Shi Changli, Wei Tongzhen.Adaptive power demand prediction model of energy storage based on Markov chain[J]. Transactions of China Electrotechnical Society, 2021, 36(S2): 563-571.
[14] 路朋, 叶林, 裴铭, 等. 风电集群有功功率模型预测协调控制策略[J]. 中国电机工程学报, 2021, 41(17): 5887-5900.
Lu Peng, Ye Lin, Pei Ming, et al.Coordinated control strategy for active power of wind power cluster based on model predictive control[J]. Proceedings of the CSEE, 2021, 41(17): 5887-5900.
[15] 陈长青, 李欣然, 谭庄熙. 考虑风电不确定性的风储调频能力[J]. 高电压技术, 2022, 48(6): 2128-2139.
Chen Changqing, Li Xinran, Tan Zhuangxi.Frequency modulation capability of wind storage considering wind power uncertainty[J]. High Voltage Engineering, 2022, 48(6): 2128-2139.
[16] Cao Minjian, Xu Qingshan, Qin Xiaoyang, et al.Battery energy storage sizing based on a model predictive control strategy with operational constraints to smooth the wind power[J]. International Journal of Electrical Power & Energy Systems, 2020, 115: 105471.
[17] 孙玉树, 唐西胜, 孙晓哲, 等. 基于MPC-HHT的多类型储能协调控制策略研究[J]. 中国电机工程学报, 2018, 38(9): 2580-2588, 2826.
Sun Yushu, Tang Xisheng, Sun Xiaozhe, et al.Research on multi-type energy storage coordination control strategy based on MPC-HHT[J]. Proceedings of the CSEE, 2018, 38(9): 2580-2588, 2826.
[18] Wu Tiezhou, Yu Wenshan, Guo Linxin.A study on use of hybrid energy storage system along with variable filter time constant to smooth DC power fluctuation in microgrid[J]. IEEE Access, 2019, 7: 175377-175385.
[19] 刘忠, 杨陈, 蒋玮, 等. 基于一致性算法的直流微电网储能系统功率分配技术[J]. 电力系统自动化, 2020, 44(7): 61-69.
Liu Zhong, Yang Chen, Jiang Wei, et al.Consensus algorithm based power distribution technology for energy storage system in DC microgrid[J]. Automation of Electric Power Systems, 2020, 44(7): 61-69.
[20] 付华, 陆鹏, 张俊男. 基于A-SA-WOA算法的直流微电网全钒液流电池储能系统功率分配策略[J/OL]. 电工技术学报: 1-12[2022-10-10].https://doi.org/10.19595/j.cnki.1000-6753.tces.211855.
Fu Hua, Lu Peng, Zhang Junnan. Power allocation strategy of DC microgrid all vanadium redox flow battery energy storage system based on A-SA-WOA algorithm[J/OL]. Transactions of China Electrotechnical Society: 1-12[2022-10-10]. https://doi.org/10.19595/j.cnki.1000-6753.tces.211855.
[21] 付菊霞, 陈洁, 滕扬新, 等. 基于集合经验模态分解的风电混合储能系统能量管理协调控制策略[J]. 电工技术学报, 2019, 34(10): 2038-2046.
Fu Juxia, Chen Jie, Teng Yangxin, et al.Energy management coordination control strategy for wind power hybrid energy storage system based on EEMD[J]. Transactions of China Electrotechnical Society, 2019, 34(10): 2038-2046.
[22] 李亚楠, 王倩, 宋文峰, 等. 混合储能系统平滑风电出力的变分模态分解-模糊控制策略[J]. 电力系统保护与控制, 2019, 47(7): 58-65.
Li Yanan, Wang Qian, Song Wenfeng, et al.Variational mode decomposition and fuzzy control strategy of hybrid energy storage for smoothing wind power outputs[J]. Power System Protection and Control, 2019, 47(7): 58-65.
[23] 王宇. 超级电容与蓄电池混合储能系统的能量管理与控制研究[D]. 哈尔滨: 哈尔滨工业大学, 2016.
[24] 孙玉树, 张国伟, 唐西胜, 等. 风电功率波动平抑下的MPC双储能控制策略研究[J]. 电工技术学报, 2019, 34(3): 571-578.
Sun Yushu, Zhang Guowei, Tang Xisheng, et al.Research on MPC and daul energy storage control strategies with wind power fluctuation mitigation[J]. Transactions of China Electrotechnical Society, 2019, 34(3): 571-578.
[25] 国家质量监督检验检疫总局, 中国国家标准化管理委员会. GB/T 19963—2011 风电场接入电力系统技术规定[S]. 北京: 中国标准出版社, 2012.
[26] 朱丽云. 考虑充放电能量不均衡的双电池系统容量配置与控制策略研究[D]. 重庆: 重庆大学, 2018.
[27] 李学斌, 刘建伟. 采用二阶滤波的混合储能系统实时功率分配方法[J]. 电网技术, 2019, 43(5): 1650-1657.
Li Xuebin, Liu Jianwei.Real-time power distribution method adopting second-order filtering for hybrid energy storage system[J]. Power System Technology, 2019, 43(5): 1650-1657.