|
|
|
| Decentralized Control Strategy for Hybrid Microgrid Cluster Bidirectional Interlinking Converters Based on Sub-Grid Priority Drive |
| Kong Huiwen1,2, Ma Jing1, Cheng Peng2, Jia Limin2,3 |
1. State Key Laboratory for Alternate Electrical Power System with Renewable Energy Sources North China Electric Power University Beijing 102206 China;
2. China Institute of Energy and Transportation Integrated Development North China Electric Power University Beijing 102206 China;
3. State Key Laboratory of Rail Traffic Control and Safety Beijing Jiaotong University Beijing 100044 China |
|
|
|
Abstract With the increasing penetration of renewable energy, hybrid AC-DC microgrid clusters (HMG-Cluster) are gradually becoming resilient solutions for new power systems. As a key component for interconnecting and synergizing AC and DC microgrids, bidirectional interlinking converter (BIC) enables efficient power management and fault ride-through in HMG systems. However, how to control and optimize the power allocation scheme of BIC remains a fundamental challenge. To fill the gap in the existing research, a priority-driven BIC decentralized control strategy is proposed to ensure the optimization of the power exchange of the HMG-Cluster according to the different priorities and capacity requirements of the sub-grids in the system.
First, the optimal power exchange model for HMG-Cluster is realized by taking the normalized AC frequency and DC voltage values as the state deviation factors of the sub-grids, and proposing a power exchange strategy with the objective of minimizing the total global deviation factor and considering the sub-grid priority and power supply capacity. Further, the optimal solution of the proposed optimization problem can be obtained by transforming the proposed power exchange model into a solvable mathematical problem and by constructing and solving the Lagrange function of the proposed optimization problem. Second, according to the optimal power exchange objective, A decentralized quasi-sag control strategy based on BICs is proposed. Since the BIC in this strategy only needs to detect the state deviation factor of the local AC frequency or DC voltage, the decentralized optimal power autonomous cooperative control can be achieved. In addition, since the main controller therein achieves accurate power tracking through dual voltage-current closed-loop, which in turn enables the HMG-Cluster energy to operate in the state of minimizing the overall deviation factor. Finally, the effectiveness of the proposed strategy is verified based on two simulation cases on a hardware-in-the-loop (HIL) system.
Based on the simulation results under the two cases, the results show the control strategy proposed can be operated under sub-grid priority-driven, i.e., the state deviation coefficient ratios of the sub-grids are always consistent regardless of the system load surge or fault conditions, and the sub-grids with higher priority have higher voltage index and priority index compared to the global shared control strategy. In addition, in the case of insufficient system dispatchable power, the low-priority sub-grids will ensure that the loads with high priority are restored first by automatically dumping loads and increasing the deviation factor. Therefore, the optimization objective value of the control strategy proposed is smaller compared with the global shared control strategy.
In summary, the following conclusions can be drawn: (1) The optimal power exchange model for HMG-Cluster with the objective of minimizing the global total deviation factor is constructed. The model is able to realize autonomous power interaction among sub-grids of the HMG-Cluster system based on the self-optimizing cooperative control of the BIC state deviation factor. (2) A decentralized quasi-sag control strategy for a BIC is proposed. Since the BIC in this strategy only needs to detect the local AC frequency and DC voltage signals, a decentralized quasi-sag control strategy based on BIC is proposed and used to realize power autonomous synergy in HMG-Cluster. (3) The decentralized control strategy based on priority driven HMG-Cluster system proposed in this article is a fundamental research that can achieve compatibility with any advanced control algorithm and achieve higher level control objectives in future research work.
|
|
Received: 25 August 2023
|
|
|
|
|
|
[1] 张昊, 李昱, 尹亚飞, 等. 直流微电网集成式高品质协同控制策略[J]. 电工技术学报, 2023, 38(23): 6345-6358.
Zhang Hao, Li Yu, Yin Yafei, et al.An integrated high-quality cooperative control strategy of DC microgrids[J]. Transactions of China Electrotechnical society, 2023, 38(23): 6345-6358.
[2] 张璐, 唐巍, 卢莹, 等. 面向新型源荷接入的交直流混合配电网关键技术研究综述[J]. 供用电, 2020, 37(10): 3-9, 21.
Zhang Lu, Tang Wei, Lu Ying, et al.Overview of hybrid AC-DC distribution network key technologies facing novel source and load integration[J]. Distribution & Utilization, 2020, 37(10): 3-9, 21.
[3] 杜燕, 言明明, 王鑫, 等. 交直流子网双边惯量约束下互联变流器动态功率控制策略[J]. 电力系统自动化, 2023, 47(4): 172-179.
Du Yan, Yan Mingming, Wang Xin, et al.Dynamic power control strategy for interlinking converter under bilateral inertia constraints in AC-DC subgrid[J]. Automation of Electric Power Systems, 2023, 47(4): 172-179.
[4] 丁明, 潘浩, 张晶晶. 分布式电源接入交直流混合微电网群优化规划研究[J]. 太阳能学报, 2021, 42(6): 54-62.
Ding Ming, Pan Hao, Zhang Jingjing.Research on optimal planning of AC-DC hybrid microgrid cluster with distributed generation access[J]. Acta Energiae Solaris Sinica, 2021, 42(6): 54-62.
[5] 楼冠男, 秦琦, 顾伟, 等. 考虑移动式储能均衡的微电网群分布式动态协同控制策略[J]. 电力系统自动化, 2023, 47(19): 74-85.
Lou Guannan, Qin Qi, Gu Wei, et al.Distributed dynamic cooperative control strategy for microgrid clusters considering equalization of mobile energy storage[J]. Automation of Electric Power Systems, 2023, 47(19): 74-85.
[6] Sun Kai, Wang Xiaosheng, Li Yun wei, et al. Parallel operation of bidirectional interfacing converters in a hybrid AC-DC microgrid under unbalanced grid voltage conditions[J]. IEEE Transactions on Power Electronics, 2017, 32(3): 1872-1884.
[7] 张国荣, 丁晓通, 彭勃, 等. 交直流混合微电网互联变流器改进控制策略[J]. 电力系统保护与控制, 2020, 48(14): 50-58.
Zhang Guorong, Ding Xiaotong, Peng Bo, et al.Improved control strategy for an AC-DC hybrid microgrid interlinking converter[J]. Power System Protection and Control, 2020, 48(14): 50-58.
[8] 郑重, 苗世洪, 李超, 等. 面向微型能源互联网接入的交直流配电网协同优化调度策略[J]. 电工技术学报, 2022, 37(1): 192-207.
Zheng Zhong, Miao Shihong, Li Chao, et al.Coordinated optimal dispatching strategy of AC-DC distribution network for the integration of micro energy Internet[J]. Transactions of China Electrotechnical Society, 2022, 37(1): 192-207.
[9] 杨义, 杨苹. 面向集中式控制的微电网信息物理系统分层建模方法[J]. 中国电机工程学报, 2022, 42(19): 7088-7102.
Yang Yi, Yang Ping.The hierarchical modeling approach for centralized control microgrid cyber physical system[J]. Proceedings of the CSEE, 2022, 42(19): 7088-7102.
[10] 杨珺, 侯俊浩, 刘亚威, 等. 分布式协同控制方法及在电力系统中的应用综述[J]. 电工技术学报, 2021, 36(19): 4035-4049.
Yang Jun, Hou Junhao, Liu Yawei, et al.Distributed cooperative control method and application in power system[J]. Transactions of China Electrotechnical Society, 2021, 36(19): 4035-4049.
[11] Zuo Kunyu, Wu Lei.A review of decentralized and distributed control approaches for islanded microgrids: novel designs, current trends, and emerging challenges[J]. The Electricity Journal, 2022, 35(5): 107138.
[12] 王干, 汤茂东, 曲小慧, 等. 一种含高比例分布式电源的直流电网组网的无差分散式协调控制[J]. 电网技术, 2023, 47(5): 2089-2098.
Wang Gan, Tang Maodong, Qu Xiaohui, et al.A non-deviation distributed coordinated control in DC power grid with high proportional renewable sources[J]. Power System Technology, 2023, 47(5): 2089-2098.
[13] Yu Hang, Niu Songyan, Shao Ziyun, et al.A scalable and reconfigurable hybrid AC-DC microgrid clustering architecture with decentralized control for coordinated operation[J]. International Journal of Electrical Power & Energy Systems, 2022, 135: 107476.
[14] Wang Junjun, Dong Chaoyu, Jin Chi, et al.Distributed uniform control for parallel bidirectional interlinking converters for resilient operation of hybrid AC-DC microgrid[J]. IEEE Transactions on Sustainable Energy, 2022, 13(1): 3-13.
[15] Lin Pengfeng, Wang Peng, Jin Chi, et al.A distributed power management strategy for multi-paralleled bidirectional interlinking converters in hybrid AC-DC microgrids[J]. IEEE Transactions on Smart Grid, 2019, 10(5): 5696-5711.
[16] 张泽华, 宋桂英, 张晓璐, 等. 考虑恒功率负载的直流微电网稳定性与鲁棒性控制策略[J]. 电工技术学报, 2023, 38(16): 4391-4405.
Zhang Zehua, Song Guiying, Zhang Xiaolu, et al.Stability and robustness control strategy of DC microgrid considering constant power load[J]. Transactions of China Electrotechnical Society, 2023, 38(16): 4391-4405.
[17] 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.
[18] 田浩, 黄文焘, 余墨多, 等. 交直流混合独立微网互联变换器自适应双向下垂控制策略[J]. 中国电机工程学报, 2022, 42(19): 7063-7074.
Tian Hao, Huang Wentao, Yu Moduo, et al.Adaptive bidirectional droop control strategy for the interlinking converter in the islanding hybrid AC-DC microgrids[J]. Proceedings of the CSEE, 2022, 42(19): 7063-7074.
[19] 郭强, 向文凯, 李山. 交直流混合微电网并联双向互联变换器环流抑制与功率控制[J]. 电气工程学报, 2022, 17(1): 31-40.
Guo Qiang, Xiang Wenkai, Li Shan.Circulating Current suppression and power control of paralleled bidirectional interlinking converters in hybrid AC-DC microgrid[J]. Journal of Electrical Engineering, 2022, 17(1): 31-40.
[20] Yang Pengcheng, Yu Miao, Wu Qiuwei, et al.Decentralized bidirectional voltage supporting control for multi-mode hybrid AC-DC microgrid[J]. IEEE Transactions on Smart Grid, 2020, 11(3): 2615-2626.
[21] Eajal A A, Yazdavar A H, El-Saadany E F, et al. Optimizing the droop characteristics of AC-DC hybrid microgrids for precise power sharing[J]. IEEE Systems Journal, 2020, 15(1): 560-569.
[22] Chang J W, Moon S I, Lee G S, et al.A new local control method of interlinking converters to improve global power sharing in an islanded hybrid AC-DC microgrid[J]. IEEE Transactions on Energy Conversion, 2020, 35(2): 1014-1025.
[23] Loh P C, Li Ding, Chai Yi kang, et al. Autonomous operation of hybrid microgrid with AC and DC subgrids[J]. IEEE Transactions on Power Electronics, 2013, 28(5): 2214-2223.
[24] Yuan Wenbin, Wang Yanbo, Liu Dong, et al.Efficiency-prioritized droop control strategy of AC microgrid[J]. IEEE Journal of Emerging and Selected Topics in Power Electronics, 2020, 9(3): 2936-2950.
[25] Cao Wenyuan, Han Minxiao, Zhang Xiahui, et al.A novel power sharing scheme of controlling parallel-operated inverters in islanded microgrids[J]. IEEE Journal of Emerging and Selected Topics in Power Electronics, 2021, 9(5): 5732-5746. |
|
|
|
2024, Vol. 39 
