基于虚拟频率的直流微电网下垂控制策略

doi:10.19595/j.cnki.1000-6753.tces.191275

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Abstract In DC microgrid, the inconsistency of DC-DC converter parameters and line impedance reduces the current sharing accuracy of droop control. Meanwhile, droop control inevitably causes DC bus voltage drop. To improve the current sharing performance among DC-DC converters, a droop control method based on virtual frequency is proposed by simulating the frequency droop control mechanism in AC microgrid. In the controller, a virtual AC variable whose frequency is proportional to the output current is constructed. The virtual frequency of each converter is shared by low bandwidth communication and the average value is calculated. The average frequency and virtual AC variable are further used to generate virtual reactive power to adjust the voltage setting point of the converter and coordinate the output current of each converter. On the premise of not causing bus voltage drop, the accuracy of load current distribution among converters is improved and the communication pressure is reduced. The stability of virtual frequency droop control is analyzed using small signal model. Finally, simulation and experiment based on Starsim and dSPACE verify the validity of the method.

Key words： DC microgrid virtual frequency droop control current sharing DC-DC converter

Received: 28 September 2019

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TM46

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	Liu Yancheng
	Zhuang Xuzhou
	Zhang Qinjin
	Zhu Pengli
	Guo Haohao

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Liu Yancheng,Zhuang Xuzhou,Zhang Qinjin等. A Virtual Current-Frequency Droop Control in DC Microgrid[J]. Transactions of China Electrotechnical Society, 2021, 36(8): 1693-1702.

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https://dgjsxb.ces-transaction.com/EN/10.19595/j.cnki.1000-6753.tces.191275 OR https://dgjsxb.ces-transaction.com/EN/Y2021/V36/I8/1693

[1] 谢文强, 韩民晓, 严稳利, 等. 考虑恒功率负荷特性的直流微电网分级稳定控制策略[J]. 电工技术学报, 2019, 34(16): 3430-3443.
Xie Wenqiang, Han Minxiao, Yan Wenli, et al.Hierarchical stability control strategy of DC micro- grid considering constant power load performance[J]. Transactions of China Electrotechnical Society, 2019, 34(16): 3430-3443.
[2] Zhang Qinjin, Liu Yancheng, Zhao Youtao, et al.A multi-mode operation control strategy for flexible microgrid based on sliding-mode direct voltage and hierarchical controls[J]. ISA Transactions, 2016, 61: 188-198.
[3] 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.
[4] Zahedi B, Norum L E.Modeling and simulation of all-electric ships with low-voltage DC hybrid power systems[J]. IEEE Transactions on Power Electronics, 2013, 28(10): 4525-4537.
[5] Gao Fei, Costabeber A, Asher G, et al.Control design and voltage stability analysis of a droop-controlled electrical power system for more electric aircraft[J]. IEEE Transactions on Industrial Electronics, 2017, 64(12): 9271-9280.
[6] Pavan Kumar Y V, Ravikumar B. A simple modular multilevel inverter topology for the power quality improvement in renewable energy based green building microgrids[J]. Electric Power Systems Research, 2016, 140: 147-161.
[7] Jiang Wei, Fahimi B.Active current sharing and sourcemanagement in fuel cell-battery hybrid power system[J]. IEEE Transactions on Industrial Electro- nics, 2010, 57(2): 752-761.
[8] 张项安, 张新昌, 唐云龙, 等. 微电网孤岛运行的自适应主从控制技术研究[J]. 电力系统保护与控制, 2014, 42(2): 81-86.
Zhang Xiang'an, Zhang Xinchang, Tang Yunlong, et al.Research on adaptive master-slave control of the islanded micro-grid[J]. Power System Protection and Control, 2014, 42(2): 81-86.
[9] Tah A, Das D.An enhanced droop control method for accurate load sharing and voltage improvement of isolated and interconnected DC microgrids[J]. IEEE Transactions on Sustainable Energy, 2016, 7(3): 1194-1204.
[10] Liu Sheng, Su Peng, Zhang Lanyong.A virtual negative inductor stabilizing strategy for DC micro- grid with constant power loads[J]. IEEE Access, 2018, 6: 59728-59741.
[11] Dragičević T, Guerrero J M, Vasquez J C, et al.Supervisory control of an adaptive-droop regulated dcmicrogrid with battery management capability[J]. IEEE Transactions on Power Electronics, 2014, 29(2): 695-706.
[12] Wang Panbao, Lu Xiaonan, Yang Xu, et al.An improved distributed secondary control method for DC microgrids with enhanced dynamic current sharing performance[J]. IEEE Transactions on Power Electronics, 2016, 31(9): 6658-6673.
[13] 支娜, 张辉, 肖曦. 提高直流微电网动态特性的改进下垂控制策略研究[J]. 电工技术学报, 2016, 31(3): 31-39.
Zhi Na, Zhang Hui, Xiao Xi.Research on the improved droop control strategy for improving the dynamic characteristics of DC microgrid[J]. Transa- ctions of China Electrotechnical Society, 2016, 31(3): 31-39.
[14] 刘琛, 赵晋斌, 王闪闪, 等. 基于单脉冲注入的直流微电网线路阻抗检测[J]. 电工技术学报, 2018, 33(11): 2584-2591.
Liu Chen, Zhao Jinbin, Wang Shanshan, et al.A line impedance identification based on single pulse injection in DC microgrid[J]. Transactions of China Electrotechnical Society, 2018, 33(11): 2584-2591.
[15] 刘子文, 苗世洪, 范志华, 等. 基于自适应下垂特性的孤立直流微电网功率精确分配与电压无偏差控制策略[J]. 电工技术学报, 2019, 34(4): 163-174.
Liu Ziwen, Miao Shihong, Fan Zhihua, et al.Accurate power allocation and zero steady-state error voltage control of the islanding DC microgird based on adaptive droop characteristics[J]. Transactions of China Electrotechnical Society, 2019, 34(4): 163-174.
[16] 王琛, 孟建辉, 王毅, 等. 含多种分布式电源的直流微电网硬件在环仿真系统设计与实现[J]. 电力系统保护与控制, 2018, 46(9): 146-154.
Wang Chen, Meng Jianhui, Wang Yi, et al.Design and implementation of hardware in-the-loop simu- lation system for DC microgrid with multiple DG units[J]. Power System Protection and Control, 2018, 46(9): 146-154.
[17] 郭伟, 赵洪山. 基于事件触发机制的直流微电网多混合储能系统分层协调控制方法[J]. 电工技术学报, 2020, 35(5): 1140-1151.
Guo Wei, Zhao Hongshan.Coordinated control method of multiple hybrid energy storage system in DC microgrid based on event-triggered mechanism[J]. Transactions of China Electrotechnical Society, 2020, 35(5): 1140-1151.
[18] Shafiee Q, Stefanovi C, Dragičević T, et al.Robust- networked control scheme for distributed secondary- control of islanded microgrids[J]. IEEE Transactions on Industrial Electronics, 2014, 61(10): 5363-5374.
[19] Lu Xiaonan, Guerrero J M, Sun Kai, et al.An improved droopcontrol method for DC microgrids based on lowbandwidth communication with DC bus voltagerestoration and enhanced current sharing accuracy[J]. IEEE Transactions on Power Electronics, 2014, 29(4): 1800-1812.
[20] 吕振宇, 吴在军, 窦晓波, 等. 基于离散一致性的孤立直流微网自适应下垂控制[J]. 中国电机工程学报, 2015, 35(17): 4397-4407.
Lü Zhenyu, Wu Zaijun, Dou Xiaobo, et al.An adaptive droop control for the islanded DC microgrid based on discrete consensus algorithm[J]. Pro- ceedings of the CSEE, 2015, 35(17): 4397-4407.
[21] 顾伟, 曹戈, 薛帅, 等. 基于有限时间一致性的直流微电网分布式协同控制方法[J]. 电力系统自动化, 2016, 40(24): 49-55, 84.
Gu Wei, Cao Ge, Xue Shuai, et al.Finite-time consensus based distributed cooperative control for DC microgrids[J]. Automation of Electric Power Systems, 2016, 40(24): 49-55, 84.
[22] Morstyn T, Savkin A, Hredzak B, et al.Multi-agent sliding mode control for state of charge balancing between battery energy storage systems distributed in a DC microgrid[J]. IEEE Transactions on Smart Grid, 2017, 9(5): 4735-4743.
[23] Peyghami S, Mokhtari H, Blaabjerg F.Decentralized load sharing in a low-voltage direct current microgrid with an adaptive droop approach based on a superi- mposed frequency[J]. IEEE Journal of Emerging and Selected Topics in Power Electronics, 2017, 5(3): 1205-1215.
[24] Peyghami S, Davari P, Mokhtari H, et al.Synchronverter- enabled DC power sharing approach for LVDC microgrids[J]. IEEE Transactions on Power Electro- nics, 2017, 32(10): 8089-8099.