|
|
|
| Modular No-Energy Storage Dynamic Voltage Restorer Multi-Parallel System and Control Method |
| Wang Chengjin1, He Jinwei1, Zhang Jiazheng1, Zhang Chenyu2, Hong Lucheng3 |
1. School of Electrical and Information Engineering Tianjin University Tianjin 300072 China;
2. State Grid Jiangsu Electric Power Research Institute Nanjing 211103 China;
3. School of Electrical Engineering Southeast University Nanjing 210096 China |
|
|
|
Abstract As a partial-capacity compensation device, the dynamic voltage restorer (DVR) can effectively utilize the residual voltage of the power grid, making it one of the most economical choices for voltage sag mitigation currently. At present, the distribution network has differentiated demand for DVR capacity. A high compensation capacity is required at the beginning of the line, while a lower one is needed at the end. The multi-machine parallel method can effectively address the challenge of a single DVR failing to meet diverse capacity requirements. During voltage sag compensation, rapid changes in voltage amplitude make it difficult for traditional distributed parallel methods to maintain current sharing during the DVR's compensation period.
This paper proposes a modular DVR parallel system and control method without energy storage. First, the leading module quickly detects voltage sags and issues state-switching commands to the following modules. The modules can perform forced shutdown of bypass thyristors in a quasi-synchronous manner. Second, a voltage regulator is deployed in the leading module to generate a current reference, which is communicated via Ethernet to subsequent modules, enabling effective compensation for voltage sags in the modular DVR parallel system.
Furthermore, this paper establishes an equivalent circuit model of a multi-machine DVR in the discrete domain. The relationship between communication delay and the control cycle is analyzed within the Ethernet communication architecture, and the distribution of the system stability region is studied for different numbers of parallel modules, communication delays, and controller parameters. Finally, the proposed system and control method are verified under multiple operating conditions and parameter settings using the RT-Lab hardware- in-the-loop simulation platform.
The following conclusions are drawn.
(1) The split topology structure with a three-phase diode rectifier bridge realizes a stable power supply to the DVR modules under the condition of no isolation transformer, maximizing the utilization of the grid's residual voltage during sag periods.
(2) During the voltage sag compensation period, the leading module generates the current reference signal and communicates it to the following modules via Ethernet, achieving efficient current-sharing control among parallel DVR modules during the compensation window.
(3) Stability analysis and simulation indicate that smaller current inner loop parameters and control cycles can enhance the system's stability margin, ensuring safe and reliable operation of the system with a greater number of parallel modules. At the same time, a fast response speed can be maintained for voltage regulation during the sag compensation process.
|
|
Received: 06 May 2025
|
|
|
|
|
|
[1] 何函洋, 肖先勇, 李成鑫, 等. 敏感用户电压暂降损失风险评估的模糊推理模型[J]. 中国电机工程学报, 2020, 40(20): 6527-6536.
He Hanyang, Xiao Xianyong, Li Chengxin, et al.Fuzzy reasoning model for risk assessment of voltage sag loss for sensitive users[J]. Proceedings of the CSEE, 2020, 40(20): 6527-6536.
[2] 孟维奇, 何晋伟, 韩俊飞, 等. 非隔离型单相三桥臂统一电能质量控制器直流侧电压灵活调节与波动抑制技术[J]. 电工技术学报, 2024, 39(20): 6517-6525.
Meng Weiqi, He Jinwei, Han Junfei, et al.DC-link voltage flexible regulation and fluctuation suppression technology of single-phase transformerless three-leg UPQC[J]. Transactions of China Electrotechnical Society, 2024, 39(20): 6517-6525.
[3] Brumsickle W E, Schneider R S, Luckjiff G A, et al.Dynamic sag correctors: cost-effective industrial power line conditioning[J]. IEEE Transactions on Industry Applications, 2001, 37(1): 212-217.
[4] 涂春鸣, 侯玉超, 郭祺, 等. 面向新能源灵活接入的多功能动态电压恢复器及其优化控制研究[J]. 电网技术, 2021, 45(9): 3487-3495.
Tu Chunming, Hou Yuchao, Guo Qi, et al.Multi-function dynamic voltage restorer and its optimal control for flexibly access of new energy sources[J]. Power System Technology, 2021, 45(9): 3487-3495.
[5] Abas N, Dilshad S, Khalid A, et al.Power quality improvement using dynamic voltage restorer[J]. IEEE Access, 2020, 8: 164325-164339.
[6] Hafezi H, Faranda R.Dynamic voltage conditioner: a new concept for smart low-voltage distribution systems[J]. IEEE Transactions on Power Electronics, 2018, 33(9): 7582-7590.
[7] 曹文远, 韩民晓, 谢文强, 等. 交直流配电网逆变器并联控制技术研究现状分析[J]. 电工技术学报, 2019, 34(20): 4226-4241.
Cao Wenyuan, Han Minxiao, Xie Wenqiang, et al.Analysis on research status of parallel inverters control technologies for AC/DC distribution net-work[J]. Transactions of China Electrotechnical Society, 2019, 34(20): 4226-4241.
[8] 王晓寰, 张纯江, 顾和荣, 等. 现场总线控制的单相逆变电源并联系统[J]. 电工技术学报, 2007, 22(10): 109-112.
Wang Xiaohuan, Zhang Chunjiang, Gu Herong, et al.Control of paralleled single phase inverters based on CAN bus[J]. Transactions of China Electrotechnical Society, 2007, 22(10): 109-112.
[9] 张敏, 陈宏舟, 樊瑞, 等. 三电平变流器模块化并联系统中点电位与零序环流机理建模与协调控制[J]. 电工技术学报, 2025, 40(5): 1-14.
Zhang Min, Chen Hongzhou, Fan Rui, et al.Modeling and coordinated control of neutral point potential and zero-sequence circulating current in modular parallel three-level converters[J]. Transactions of China Electrotechnical Society, 2025, 40(5): 1-14.
[10] 郭倩, 林燎源, 武宏彦, 等. 一种改进的分布式电源无功功率精确分配下垂控制策略[J]. 电力系统自动化, 2015, 39(15): 30-34, 74.
Guo Qian, Lin Liaoyuan, Wu Hongyan, et al.An improved droop control strategy for accurate reactive power sharing among distributed generators[J]. Automation of Electric Power Systems, 2015, 39(15): 30-34, 74.
[11] Xin Huanhai, Zhang Leiqi, Wang Zhen, et al.Control of island AC microgrids using a fully distributed approach[J]. IEEE Transactions on Smart Grid, 2015, 6(2): 943-945.
[12] He Jinwei, Li Yunwei, Guerrero J M, et al.An islanding microgrid power sharing approach using enhanced virtual impedance control scheme[J]. IEEE Transactions on Power Electronics, 2013, 28(11): 5272-5282.
[13] 张波, 颜湘武, 黄毅斌, 等. 虚拟同步机多机并联稳定控制及其惯量匹配方法[J]. 电工技术学报, 2017, 32(10): 42-52.
Zhang Bo, Yan Xiangwu, Huang Yibin, et al.Stability control and inertia matching method of multi-parallel virtual synchronous generators[J]. Transactions of China Electrotechnical Society, 2017, 32(10): 42-52.
[14] He Jinwei, Li Yunwei, Blaabjerg F.An enhanced islanding microgrid reactive power, imbalance power, and harmonic power sharing scheme[J]. IEEE Transactions on Power Electronics, 2015, 30(6): 3389-3401.
[15] Johnson B B, Sinha M, Ainsworth N G, et al.Synthesizing virtual oscillators to control islanded inverters[J]. IEEE Transactions on Power Electronics, 2016, 31(8): 6002-6015.
[16] Abas N, Dilshad S, Khalid A, et al.Power quality improvement using dynamic voltage restorer[J]. IEEE Access, 2020, 8: 164325-164339.
[17] 施烨, 吴在军, 窦晓波, 等. 单相动态电压恢复器复合控制技术[J]. 电工技术学报, 2015, 30(17): 85-95.
Shi Ye, Wu Zaijun, Dou Xiaobo, et al.Study on compound control technology of single-phase dynamic voltage restorer[J]. Transactions of China Electrotechnical Society, 2015, 30(17): 85-95.
[18] 涂春鸣, 卢柏桦, 郭祺, 等. 基于最小能量补偿法的串联电容耦合型动态电压恢复器运行特性分析[J]. 电工技术学报, 2020, 35(17): 3727-3738.
Tu Chunming, Lu Baihua, Guo Qi, et al.Operating characteristics analysis of series capacitance coupled dynamic voltage restorer based on minimum energy compensation method[J]. Transactions of China Elec-trotechnical Society, 2020, 35(17): 3727-3738.
[19] Wen Bo, Boroyevich D, Burgos R, et al.Small-signal stability analysis of three-phase AC systems in the presence of constant power loads based on measured d-q frame impedances[J]. IEEE Transactions on Power Electronics, 2015, 30(10): 5952-5963. |
|
|
|
2026, Vol. 41 
