Optimal State-of-charge Balancing Control for Paralleled Battery Energy Storage Devices in Islanded Microgrid
Wang Weixin1, Duan Jiandong1, Zhang Runsong2, Guo Haifeng1, Sun Li1
1.School of Electrical Engineering & Automation Harbin Institute of Technology Harbin 150001 China 2.Equipment Manufacturing Company China National Petroleum Corporation Beijing 100007 China
摘要 基于下垂控制策略的蓄电池储能管理方案被广泛应用于孤岛电网,但在放电过程中并联蓄电池储能设备相互间将出现电荷状态(State of Charge,SOC)差异,使某些储能设备提前退出运行,显著削弱了系统稳定性。针对上述问题,提出一种适用于多储能设备的SOC一致性控制策略,并进行优化。将SOC作为下垂控制器输入量,根据SOC实时调节储能设备的输出功率,使并联储能设备的SOC在放电过程中逐渐趋于一致,进而在孤岛电网频率偏移约束以及逆变器最大输出有功功率限制下对加速因子进行在线优化,显著减少了并联蓄电池储能设备间SOC最终差值,达到更佳的均衡效果。仿真与实验结果验证了SOC一致性优化控制策略理论分析的正确性和实现方案的有效性。
Abstract：The droop controlled battery energy storage device (BESD) becomes more and more commonplace to maintain the stability of the islanded power system.In discharging process,the state-of-charge (SOC) error between different BESDs could force some BESDs to cease operation earlier than expectation,which eliminates the system stability.An optimal SOC balancing control for parallel BESDs in islanded microgrid is proposed in this paper to effectively suppress the SOC error.The SOC of the battery is employed in the droop controller to adjust the output active power of BESD in real-time,and thus decline the SOC error among parallel BESDs.In addition,to achieve better performance of SOC balancing under the constraints of inverter’s maximum output power and islanded microgrid’s deviation frequency,the accelerating factor is optimized online based on the state of operation in order to diminish the final difference among SOCs.The effectiveness of the control scheme is validated by simulation and experiment results.
[1] Guerrero J M,Vicuna L G,Matas J,et al.Steady-state invariant frequency and amplitude droop control using adaptive output impedance for parallel connected UPS inverters[C].IEEE Annual Applied Power Elecrtonics Conference and Exposition,Austin,2005. [2] Xu Zhuang,Li Rui,Zhu Hui,et al.Control of parallel multiple converters for direct drive permanent magnet wind power generation systems[J].IEEE Transactions on Power Electronics,2012,27(3):1259-1270. [3] Wang Xianwei,Zhou Fang,Li Jing,et al.Modeling and control of dual-stage high-power multifunctional PV system in d-q-0 coordinate[J].IEEE Transactions on Industrial Electronics,2013,60(4):1556-1570. [4] Yasser A I M,Ehab F E S.Adaptive decentralized droop controller to preserve power sharing stability of paralleled inverters in distributed generation microgrid[J].IEEE Transactions on Power Electronics,2008,23(6):2806-2815. [5] Lee C T,Jiang R P,Cheng P T.A grid synchronization method for droop controlled distributed energy resource converter[J].IEEE Transactions on Industrial Application,2013,49(2):954-962. [6] Josep M,Mukul C,Tzung-Lin L,et al.Adanced control architectures for intelligent microgrid-partⅡ:power quality,energy storage,and AC/DC microgrid[J].IEEE Transactions on Industrial Electronics,2013,60(4):1263-1270. [7] 王成山,武震,李鹏.微电网关键技术研究[J].电工技术学报,2014,29(2):1-12. Wang Chengshan,Wu Zhen,Li Peng.Research on key technologies of microgrid[J].Transactions of China Electrotechnical Society,2014,29(2):1-12. [8] 戚永志,刘玉田.风光储联合系统输出功率滚动优化与实时控制[J].电工技术学报,2014,29(8):265-273. Qi Yongzhi,Liu Yutian.Output power rolling optimization and real-time control in wind -photovoltaic-storage hybrid system[J].Transactions of China Electrotechnical Society,2014,29(8):265-273. [9] 别朝红,李更丰,谢海鹏.计及负荷与储能装置协调优化的微网可靠性评估[J].电工技术学报,2014,29(2):64-73. Bie Chaohong,Li Gengfeng,Xie Haipeng.Reliability evaluation of microgrids considering coordinative optimization of loads and storage device[J].Transactions of China Electrotechnical Society,2014,29(2):64-73. [10]Jayasinghe S D G,Vilathgamuwa D M,Madawala U K. A dual inverter based supercapacitor direct integration scheme for wind energy conversion systems[J].IEEE Transactions on Industry Applications,2013,49(3):1023-1030. [11]Maharjan L,Yamagishi T,Akagi H.Active-power control of individual converter cells for a battery energy storage system based on a multilevel cascade PWM converter[J].IEEE Transactions on Power Elecrtonics,2012,27(3):1099-1107. [12]Brekken T K,Yokochi A,Jouanne A V,et al.Optimal energy storage sizing and control for wind power applications[J].IEEE Transaction on Sustainable Energy,2011,2(1):69-77. [13]Vivek A,Kasemsak U,Raymond A D,et al.Development and validation of a battery model useful for discharging and charging power control and lifetime estimation[J].IEEE Transactions on Energy Conversion,2010,25(3):821-832. [14]彭思敏,窦真兰,凌志斌,等.并联型储能系统孤网运行协调控制策略[J].电工技术学报,2013,28(5):128-134. Peng Simin,Dou Zhenlan,Ling Zhibin,et al.Cooperative control for parallel-connected battery energy storage system of islanded power system[J].Transactions of China Electrotechnical Society,2013,28(5):128-134. [15]陆晓楠,孙凯,黄立培,等.直流微电网储能系统中带有直流母线电压跌落补偿功能的负荷功率动态分配方法[J].中国电机工程学报,2013,33(16):37-46. Lu Xiaonan,Sun Kai,Huang Lipei,et al.Dynamic load power sharing method with elimination of bus voltage deviation for energy storage systems in DC micro-grid[J].Proceedings of the CSEE,2013,33(16):37-46. [16]Kakigana H,Miura Y,Ise T.Distribution voltage control for dc microgrids using fuzzy control and gain scheduling technique[J].IEEE Transactions on Power Electronics,2013,28(5):2246-2258. [17]Lu X N,Sun K,Guerrero J M,et al.State-of-charge balance using adaptive droop control for distributed energy storage systems in DC microgrid applications[J].IEEE Transactions on Industrial Electronics,2014,61(6):2804-2815. [18]Mohamed Y A,EI-Saadany E F.Adaptive decentralized droop controller to preserve power sharing stability of paralleled inverters in distributed generation microgrid[J].IEEE Transactions on Power Electronics,2008,23(6):2806-2817.
2015, Vol. 30 
