Control Strategy of Bidirectional DC-DC Converter for Energy Storage Battery
Yue Gaili1, Zhang Zhe1, Du Gaunghui1, Xu Zhenzhen1, Yao Jiadong2
1. College of Electrical and Control Engineering Xi' an University of Science and Technology Xi' an 710054 China; ; 2. Shaanxi Lingyun Technology Co. Ltd Xi' an 710119 China
Abstract:Due to the advantages of high power density, low current ripple, and small system size, three-phase interleaved parallel Buck-Boost converters are widely used in energy storage, distributed generation, and other fields. However, because of the inconsistency of parasitic parameters between the parallel modules during the operation of the converter, the current of each phase is unbalanced. This paper proposes a current sharing control method based on sliding mode control and model predictive control (SMC-MPC). Finally, simulation and experiment verify the effectiveness of the proposed control method. Firstly, the characteristics of the three-phase interleaved parallel Buck-Boost converter in Buck and Boost modes and the main waveforms of the circuit when the duty cycle is greater than 2/3 in Boost mode are analyzed. The current and voltage ripple expressions in the full-duty cycle range of the converter in different working modes are given. The discrete state space equations in the two modes are obtained by deriving the continuous state space equations of the single-phase Buck-Boost converter in different operating modes. Then, this paper constructs the objective evaluation function, substitutes the obtained state-space equation into the objective evaluation function, and minimizes the evaluation function. As a result, the optimal duty cycle expression of the converter under the control of predictive control in different working modes is obtained, and the balanced control of the current of each phase is achieved by the duty cycle compensation method. Secondly, the principle of sliding mode control is analyzed for the voltage outer loop. The instantaneous inductance current and steady-state current deviation, the output voltage deviation, and the integral of the output voltage deviation are selected as the sliding mode control state variables. Then, the sliding mode surface is established. The sliding coefficient is determined, and the reference expression of the inductance current is obtained according to the accessibility principle of sliding mode control. Thus, the converter can improve the system's response speed under the premise of current sharing in the entire duty cycle range, which has strong anti-interference ability. Finally, a simulation platform was built based on Matlab/Simulink simulation software, and an experimental prototype with 500 W power was made. The results show that the proposed SMC-MPC current sharing control strategy can achieve the balanced control of inductance current across the entire duty cycle and different operating modes, significantly improving the current sharing accuracy. In addition, when the load is disturbed, both the three-phase inductor's current sharing and rapid output current stabilization can be achieved. Compared with the PI-MPC control strategy, the response time to steady state is significantly faster, and its overshoot is reduced considerably, reflecting stronger robustness.
岳改丽, 张哲, 杜光辉, 徐振振, 姚嘉栋. 储能电池双向DC-DC变换器控制策略[J]. 电工技术学报, 2025, 40(20): 6618-6629.
Yue Gaili, Zhang Zhe, Du Gaunghui, Xu Zhenzhen, Yao Jiadong. Control Strategy of Bidirectional DC-DC Converter for Energy Storage Battery. Transactions of China Electrotechnical Society, 2025, 40(20): 6618-6629.
[1] 董坤, 赵剑锋, 孙睿晨, 等. 含新型负荷元件的电力负荷建模方法研究现状与展望[J]. 电力系统自动化, 2023, 47(23): 70-83. Dong Kun, Zhao Jianfeng, Sun Ruichen, et al.Research status and prospects of modeling methods for power loads with new load elements[J]. Automation of Electric Power Systems, 2023, 47(23): 70-83. [2] 夏向阳, 陈贵全, 刘俊翔, 等. 储能系统直流侧纹波电流对锂离子电池寿命影响分析及优化控制策略[J]. 电工技术学报, 2023, 38(22): 6218-6229. Xia Xiangyang, Chen Guiquan, Liu Junxiang, et al.Analysis of the impact of DC-side ripple current on lithium-ion battery life in energy storage systems and optimal control strategies[J]. Transactions of China Electrotechnical Society, 2023, 38(22): 6218-6229. [3] 关维德, 李涛, 钟健, 等. 电机控制器直流侧前置双有源桥DC-DC变换器的模型预测与应力优化混合控制[J]. 电工技术学报, 2024, 39(12): 3787-3801. Guan Weide, Li Tao, Zhong Jian, et al.Hybrid control of model prediction and current stress optimization for dual active bridge DC-DC converter in motor drive systems[J]. Transactions of China Electro- technical Society, 2024, 39(12): 3787-3801. [4] 鲁静, 同向前, 张嘉翔, 等. L-LLC谐振型双向DC-DC变换器的复合最优轨迹控制策略研究[J]. 电工技术学报, 2020, 35(增刊1): 60-69. Lu Jing, Tong Xiangqian, Zhang Jiaxiang, et al.Research on compound optimal trajectory control strategy of L-LLC resonant bidirectional DC-DC converter[J]. Transactions of China Electrotechnical Society, 2020, 35(S1): 60-69. [5] 刘海军, 张理, 张乔根, 等. 基于堆叠滤波结构的高电压比低纹波隔离型DC-DC制氢变换器[J]. 电工技术学报, 2024, 39(18): 5755-5767. Liu Haijun, Zhang Li, Zhang Qiaogen, et al.High- conversion-ratio low-ripple isolated DC-DC hydrogen converter based on stacked filter structure[J]. Transa- ctions of China Electrotechnical Society, 2024, 39(18): 5755-5767. [6] 张洋, 丘东元, 张波, 等. DC-DC变换器分层级构造方法[J]. 电工技术学报, 2023, 38(20): 5473-5487. Zhang Yang, Qiu Dongyuan, Zhang Bo, et al.Hierarchical synthesis methods of DC-DC con- verters[J]. Transactions of China Electrotechnical Society, 2023, 38(20): 5473-5487. [7] 苏冰, 王玉斌, 王璠, 等. 基于耦合电感的多相交错并联双向DC-DC变换器及其均流控制[J]. 电工技术学报, 2020, 35(20): 4336-4349. Su Bing, Wang Yubin, Wang Fan, et al.Multi-phase interleaved bidirectional DC-DC converter with coupled inductors and current sharing control strategy[J]. Transactions of China Electrotechnical Society, 2020, 35(20): 4336-4349. [8] 马帅旗, 任思嘉, 贺海育, 等. 储能交错并联双向DC-DC变换器的自抗扰控制[J]. 电子测量技术, 2024, 47(13): 35-44. Ma Shuaiqi, Ren Sijia, He Haiyu, et al.Active disturbance rejection control of energy storage inter- leaved parallel bidirectional DC-DC converter[J]. Elec- tronic Measurement Technology, 2024, 47(13): 35-44. [9] Chathurangi D, Jayatunga U, Perera S, et al.Com- parative evaluation of solar PV hosting capacity enhancement using Volt-var and Volt-Watt control strategies[J]. Renewable Energy, 2021, 177: 1063-1075. [10] 李朝阳, 张佰富, 韩肖清, 等. 基于自适应虚拟阻尼控制的并联双向变换器间环流抑制方法[J]. 高电压技术, 2020, 46(5): 1550-1559. Li Chaoyang, Zhang Baifu, Han Xiaoqing, et al.Circulating current suppression method for paralleled bi-directional power converters based on adaptive virtual damping control[J]. High Voltage Engineering, 2020, 46(5): 1550-1559. [11] 章宝歌, 张振, 王天鹏, 等. 一种适用于BESS的交错并联双向DC/DC变换器[J]. 太阳能学报, 2022, 43(1): 277-283. Zhang Baoge, Zhang Zhen, Wang Tianpeng, et al.An interleaved parallel bidirectional DC/DC converter for BESS[J]. Acta Energiae Solaris Sinica, 2022, 43(1): 277-283. [12] Duan Minghang, Duan Jiandong, Sun Li.Sensorless current-sharing scheme for multiphase DC-DC boost converters[J]. IEEE Transactions on Power Electro- nics, 2023, 38(2): 1398-1405. [13] Wang Jianing, Pei Wei, Hu Jiawen, et al.Five-phase LLC resonant DC/DC converter utilizing CLC filter for current sharing[J]. IEEE Transactions on Indu- strial Electronics, 2023, 70(9): 8634-8644. [14] 黄丫, 田小建, 吴戈, 等. 适用于激光器脉冲驱动系统的低纹波交错并联Boost变换器[J]. 电源学报, 2023, 21(2): 46-54. Huang Ya, Tian Xiaojian, Wu Ge, et al.Low voltage ripple interleaved parallel Boost converter for pulsed laser driver[J]. Journal of Power Supply, 2023, 21(2): 46-54. [15] Wang Haojie, Han Minxiao, Han Renke, et al.A decentralized current-sharing controller endows fast transient response to parallel DC-DC converters[J]. IEEE Transactions on Power Electronics, 2018, 33(5): 4362-4372. [16] Xu Liangcai, Ma Rui, Xie Renyou, et al.Offset-free model predictive control of fuel cell DC-DC boost converter with low-complexity and high-robustness[J]. IEEE Transactions on Industrial Electronics, 2023, 70(6): 5784-5796. [17] 李欣洋, 杨平, 范文, 等. 低输入电流纹波的交错并联三态Boost变换器[J]. 中国电机工程学报, 2021, 41(8): 2834-2844. Li Xinyang, Yang Ping, Fan Wen, et al.Interleaved tri-state Boost converter with low input current ripple[J]. Proceedings of the CSEE, 2021, 41(8): 2834-2844. [18] 郭强, 李山, 谢诗云, 等. 多相交错并联DC-DC变换器单电流传感器控制策略[J]. 电工技术学报, 2022, 37(4): 964-975. Guo Qiang, Li Shan, Xie Shiyun, et al.Single-sensor sampling current control strategy of multiphase interleaved DC-DC converters[J]. Transactions of China Electrotechnical Society, 2022, 37(4): 964-975. [19] 高圣伟, 李永宵, 田金锐, 等. 双频DC-DC变换器的磁集成技术[J]. 电工技术学报, 2024, 39(13): 4025-4036. Gao Shengwei, Li Yongxiao, Tian Jinrui, et al.Magnetic integration of double frequency DC-DC converter[J]. Transactions of China Electrotechnical Society, 2024, 39(13): 4025-4036. [20] Lin Nan, Zhao Yue, Mantooth H A.An effective current balancing method for inverters with paralleled silicon carbide power modules[J]. IEEE Transactions on Industry Applications, 2023, 59(6): 6986-7000. [21] 周伟成, 周永忠, 张海军, 等. 最大电流均流技术及应用[J]. 电力电子技术, 2008, 42(1): 45-47. Zhou Weicheng, Zhou Yongzhong, Zhang Haijun, et al.Maximal current sharing method and its appli- cation[J]. Power Electronics, 2008, 42(1): 45-47. [22] 王华俊. 微电网储能侧的双DC-DC变换器控制研究[D]. 淮南: 安徽理工大学, 2024. Wang Huajun.Research on control of dual DC-DC converter on energy storage side of microgrid[D]. Huainan: Anhui University of Science and Tech- nology, 2024. [23] Zhang Meng, Chen Jing, Lan Xianbao, et al.Simu- lation on staggered parallel boost converter with double integral sliding mode control[J]. Journal of Physics: Conference Series, 2021, 1983(1): 012076. [24] Gordillo J, Aguilar C.A simple sensorless current sharing technique for multiphase DC-DC buck con- verters[J]. IEEE Transactions on Power Electronics, 2017, 32(5): 3480-3489. [25] 游江, 孟繁荣, 张敬南. 基于回路成形的并联DC/DC变换器均流控制器设计[J]. 中国电机工程学报, 2019, 39(2): 585-593, 655. You Jiang, Meng Fanrong, Zhang Jingnan.Loop- shaping based current sharing controller design for parallel DC/DC converters[J]. Proceedings of the CSEE, 2019, 39(2): 585-593, 655. [26] 梅杨, 陈丽莎, 黄伟超, 等. 交错并联Buck-Boost变换器模型预测控制方法[J]. 电气传动, 2017, 47(7): 32-36. Mei Yang, Chen Lisha, Huang Weichao, et al.Model predictive control method for interleaved parallel Buck-Boost converter[J]. Electric Drive, 2017, 47(7): 32-36.