|
|
|
| Stability and Robustness Control Strategy of DC Microgrid Considering Constant Power Load |
| Zhang Zehua1,2, Song Guiying1,2, Zhang Xiaolu3, Zhou Jiyao1,2, Wang Ruimin1,2 |
1. State Key Laboratory of Reliability and Intelligence of Electrical Equipment Hebei University of Technology Tianjin 300130 China;
2. Key Laboratory of Electromagnetic Field and Electrical Apparatus Reliability of Hebei Province Hebei University of Technology Tianjin 300130 China;
3. North China Electric Power Research Institute Co. Ltd Beijing 100045 China |
|
|
|
Abstract The DC microgrid has many loads: constant impedance load (CIL) and constant power load (CPL). The negative impedance characteristic of CPL will reduce the system damping and cause the system to collapse. However, the traditional linear control only guarantees stability in the small neighborhood of the equilibrium point and needs to make a trade-off between the stability margin and the dynamic performance. In recent years, many nonlinear control methods have been proposed, but most require parameter design and general dynamic performance. In order to solve these problems, this paper proposes an adaptive backstepping control, which guarantees the global large signal stability and fast dynamic response of the system.
Firstly, the model is transformed into Brunovsky's canonical form using the exact feedback linearization technique to solve the non-minimum phase problem and avoid the influence of parasitic resistance on the primary controller. Secondly, to improve the robustness of the system, an extended nonlinear disturbance observer and an input voltage observer based on the dynamic model of the converter are used to estimate and compensate for external disturbances, parasitic resistance, and lumped uncertainty disturbances online. The optimized adaptive backstepping control can operate with limited and imprecise initial parameters of the system. The large-signal stability of the controller is verified based on Lyapunov and mixed potential function theory. The design principle of controller parameters and the stability boundary diagram of the system are given to ensure global trajectory tracking and fast dynamic response of the output voltage.
The simulation and hardware in the loop experiment of DC microgrid under various working conditions, compared with the literature in Ref.[22], show that when the input voltage step changes, the overshoot and recovery time are reduced by 81.25% and 88%, respectively, and the inductance current does not reverse overshoot. When the CPL step changes, its overshoot and recovery time are reduced by 41.89% and 75%, respectively. When the CIL step changes, the overshoot and recovery time are reduced by 41.56% and 75%, respectively. At the same time, the proposed control is robust to model parameter uncertainties and parasitic parameters, which can be better applied to industrial applications under various harsh conditions. In addition, the proposed control is tested for controller switching and large signal stability. Compared with the classical PI control, the overshoot and recovery time of the proposed control are reduced by 57.14% and 92.5%, respectively. Finally, the effectiveness and superiority of the proposed control are further verified through the DC microgrid experimental platform.
The following conclusions are drawn from the simulation and experimental results: (1) Compared with BSC+NDO, it reduces the parameters required for controller design and the dependence on sensors, considers the system parasitic parameter interference, and has good stability and robustness. (2) Compared with classical PI control, the proposed control can stabilize the limit cycle oscillation system and has a better dynamic response. (3) A mixed potential function large signal stability criterion for nonlinear control is proposed, and the controller parameter design criteria and large signal stability boundary diagram are provided.
|
|
Received: 18 April 2022
|
|
|
|
|
|
[1] Xu Luona, Guerrero J M, Lashab A, et al.A review of DC shipboard microgrids part I: power architectures, energy storage and power converters[J]. IEEE Transactions on Power Electronics, 2022, 37(5): 5155-5172.
[2] 朱晓荣, 李铮, 孟凡奇. 基于不同网架结构的直流微电网稳定性分析[J]. 电工技术学报, 2021, 36(1): 166-178.
Zhu Xiaorong, Li Zheng, Meng Fanqi.Stability analysis of DC microgrid based on different grid structures[J]. Transactions of China Electrotechnical Society, 2021, 36(1): 166-178.
[3] 程林, 万宇翔, 齐宁, 等. 含多种分布式资源的配用电系统运行可靠性研究评述及展望[J]. 电力系统自动化, 2021, 45(22): 191-207.
Cheng Lin, Wan Yuxiang, Qi Ning, et al.Review and prospect of research on operation reliability of power distribution and consumption system considering various distributed energy resources[J]. Automation of Electric Power Systems, 2021, 45(22): 191-207.
[4] Alshareef M, Lin Zhengyu, Li Fulong, et al.A grid interface current control strategy for DC micro- grids[J]. CES Transactions on Electrical Machines and Systems, 2021, 5(3): 249-256.
[5] 郭慧, 汪飞, 顾永文, 等. 基于电压分层控制的直流微电网及其储能扩容单元功率协调控制策略[J]. 电工技术学报, 2022, 37(12): 3117-3131.
Guo Hui, Wang Fei, Gu Yongwen, et al.Coordinated power control strategy for DC microgrid and storage expansion unit based on voltage hierarchical control[J]. Transactions of China Electrotechnical Society, 2022, 37(12): 3117-3131.
[6] Peyghami S, Palensky P, Blaabjerg F.An overview on the reliability of modern power electronic based power systems[J]. IEEE Open Journal of Power Electronics, 2020, 1: 34-50.
[7] 黄远胜, 刘和平, 苗轶如, 等. 基于并联虚拟电阻的级联DC-DC变换器稳定控制方法[J]. 电工技术学报, 2020, 35(18): 3927-3937.
Huang Yuansheng, Liu Heping, Miao Yiru, et al.Cascaded DC-DC converter stability control method based on paralleling virtual resistor[J]. Transactions of China Electrotechnical Society, 2020, 35(18): 3927-3937.
[8] Singh S, Gautam A R, Fulwani D.Constant power loads and their effects in DC distributed power systems: a review[J]. Renewable and Sustainable Energy Reviews, 2017, 72: 407-421.
[9] Cespedes M, Xing Lei, Sun Jian.Constant-power load system stabilization by passive damping[J]. IEEE Transactions on Power Electronics, 2011, 26(7): 1832-1836.
[10] 季宇, 王东旭, 吴红斌, 等. 提高直流微电网稳定性的有源阻尼方法[J]. 电工技术学报, 2018, 33(2): 370-379.
Ji Yu, Wang Dongxu, Wu Hongbin, et al.The active damping method for improving the stability of DC microgrid[J]. Transactions of China Electrotechnical Society, 2018, 33(2): 370-379.
[11] Zhang Xin, Zhong Qingchang, Kadirkamanathan V, et al.Source-side series-virtual-impedance control to improve the cascaded system stability and the dynamic performance of its source converter[J]. IEEE Transactions on Power Electronics, 2019, 34(6): 5854-5866.
[12] 滕昌鹏, 王玉斌, 周博恺, 等. 含恒功率负载的直流微网大信号稳定性分析[J]. 电工技术学报, 2019, 34(5): 973-982.
Teng Changpeng, Wang Yubin, Zhou Bokai, et al.Large-signal stability analysis of DC microgrid with constant power loads[J]. Transactions of China Elec- trotechnical Society, 2019, 34(5): 973-982.
[13] Jiang Jianbo, Liu Fei, Pan Shangzhi, et al.A conservatism-free large signal stability analysis method for DC microgrid based on mixed potential theory[J]. IEEE Transactions on Power Electronics, 2019, 34(11): 11342-11351.
[14] 刘宿城, 李响, 秦强栋, 等. 直流微电网集群的大信号稳定性分析[J]. 电工技术学报, 2022, 37(12): 3132-3147.
Liu Sucheng, Li Xiang, Qin Qiangdong, et al.Large signal stability analysis for DC microgrid clusters[J]. Transactions of China Electrotechnical Society, 2022, 37(12): 3132-3147.
[15] Zeng Jianwu, Zhang Zhe, Qiao Wei.An inter- connection and damping assignment passivity-based controller for a DC-DC Boost converter with a constant power load[J]. IEEE Transactions on Industry Applications, 2014, 50(4): 2314-2322.
[16] Khan M S, Ahmad I, Abideen F Z U. Output voltage regulation of FC-UC based hybrid electric vehicle using integral backstepping control[J]. IEEE Access, 2019, 7: 65693-65702.
[17] Zheng Changming, Dragičević T, Zhang Jiasheng, et al.Composite robust quasi-sliding mode control of DC-DC Buck converter with constant power loads[J]. IEEE Journal of Emerging and Selected Topics in Power Electronics, 2021, 9(2): 1455-1464.
[18] He Wei, Ortega R.Design and implementation of adaptive energy shaping control for DC-DC converters with constant power loads[J]. IEEE Transactions on Industrial Informatics, 2020, 16(8): 5053-5064.
[19] Yuan Cong, Bai Hao, Ma Rui, et al.Large-signal stability analysis and design of finite-time controller for the electric vehicle DC power system[J]. IEEE Transactions on Industry Applications, 2022, 58(1): 868-878.
[20] Chen Wenhua, Yang Jun, Guo Lei, et al.Disturbance- observer-based control and related methods-an overview[J]. IEEE Transactions on Industrial Elec- tronics, 2016, 63(2): 1083-1095.
[21] Hassan M A, Su Chunlian, Chen Fuzen, et al.Adaptive passivity-based control of DC-DC Boost power converter supplying constant power and constant voltage loads[J]. IEEE Transactions on Industrial Electronics, 2022, 69(6): 6204-6214.
[22] Xu Qianwen, Zhang Chuanlin, Wen Changyun, et al.A novel composite nonlinear controller for stabi- lization of constant power load in DC microgrid[J]. IEEE Transactions on Smart Grid, 2019, 10(1): 752-761.
[23] 崔健, 王久和, 李建国, 等. 基于扩张状态观测器估计补偿的Buck变换器带恒功率负载无源控制[J]. 电工技术学报, 2019, 34(增刊1): 171-180.
Cui Jian, Wang Jiuhe, Li Jianguo, et al.Research on passivity-based control of Buck converter with constant power load based on extend state observer estimating and compensating[J]. Transactions of China Electrotechnical Society, 2019, 34(S1): 171-180.
[24] Ginoya D, Shendge P D, Phadke S B.Sliding mode control for mismatched uncertain systems using an extended disturbance observer[J]. IEEE Transactions on Industrial Electronics, 2014, 61(4): 1983-1992.
[25] Li Po, Li Ruiyu, Shao Tianying, et al.Composite adaptive model predictive control for DC-DC Boost converters[J]. IET Power Electronics, 2018, 11(10): 1706-1717.
[26] Gui Yonghao, Han Renke, Guerrero J M, et al.Large- signal stability improvement of DC-DC converters in DC microgrid[J]. IEEE Transactions on Energy Conversion, 2021, 36(3): 2534-2544.
[27] 游逍遥, 刘和平, 苗轶如, 等. 带恒功率负载的双极性直流系统稳定性分析及其有源阻尼方法[J]. 电工技术学报, 2022, 37(4): 918-930.
You Xiaoyao, Liu Heping, Miao Yiru, et al.Stability analysis and active damping method of the bipolar DC system with constant power loads[J]. Transactions of China Electrotechnical Society, 2022, 37(4): 918-930. |
|
|
|
2023, Vol. 38 
