交流微电网直流互联变流器系统多阻抗优化控制

doi:10.11930/j.issn.1004-9649.202203057

摘要/Abstract

摘要： 为了实现系统功率双向传输控制、有功无功解耦控制、故障隔离等目标，2个交流微电网通过背靠背结构的电压源型变流器（VSC）进行直流互联。在功率双向流动系统中，定功率控制模式下变流器作为功率负载时，其直流或交流端口阻抗会呈负阻抗特性，进而减小系统阻尼，容易让系统失去稳定。针对该问题，提出一种多阻抗优化控制方法，不仅将该变流器直流和交流端口的负阻抗优化为正阻抗，还对定直流电压模式下的变流器直流端口阻抗进行优化，减小两侧阻抗的相位差，多角度增强系统的稳定性。首先，对系统的结构和控制进行了简单介绍。其次，对优化前两侧变流器多个端口阻抗的特性进行分析。然后，分析了多阻抗优化控制的工作机理，并得到优化后的端口阻抗模型。依据最小环路比和奈奎斯特稳定判据，对比分析了优化前后系统的稳定性。结果表明：提出的多阻抗优化控制方法能对系统中多个端口阻抗进行优化，不仅可以将原交、直流侧的阻抗特性从负优化为正，还可以减小直流侧阻抗间的相位差，使系统保持更大的稳定裕度。最后通过Matlab/Simulink仿真对所提控制方法的有效性进行了验证。

关键词: 交流微电网, 变流器, 小信号建模, 稳定性分析, 优化控制

Abstract: The two AC microgrids are DC interconnected through back-to-back structured VSC converters. Usually one side converter adopts DC voltage control, and the other side converter adopts constant active power control. Under bidirectional power flow, when the power-controlled converter mode is used as a power load, its DC or AC port impedance will show negative impedance characteristics, reducing system damping and stability. To solve this problem, a multi-impedance optimization control is proposed, which not only optimizes the negative impedance to positive impedance, but also reduces the phase difference on DC side, enhancing the stability of the system completely. First, the structure of the AC micro-grid DC interconnected converter system, the topology and control of the converter are briefly introduced. Secondly, small-signal modeling was modelled of the multiple ports of the converters on both sides before the optimization, and the impedance characteristics were analyzed. Then, the working mechanism of multi-impedance optimization control is analyzed, and the optimized port impedance is re-modeled. The results show that the proposed multi-impedance optimization control can optimize the impedance of multiple ports in the system. It can not only optimize the negative impedance of the original AC and DC sides to positive impedance, but also reduce the phase difference between the impedances of the DC side，maintaining a larger stability margin and greatly improving system stability.

Key words: AC microgrid, current converter, small signal modeling, stability analysis, coordinative control

刘振国, 金铭, 于海, 陈文涛, 杨定乾. 交流微电网直流互联变流器系统多阻抗优化控制[J]. 中国电力, 2023, 56(2): 93-101,156.

LIU Zhenguo, JIN Ming, YU Hai, CHEN Wentao, YANG Dingqian. A Multi-impedance Optimization Control for AC Microgrid DC Interconnected Converter System[J]. Electric Power, 2023, 56(2): 93-101,156.

导出引用管理器 EndNote|Ris|BibTeX

链接本文: https://www.electricpower.com.cn/CN/10.11930/j.issn.1004-9649.202203057

https://www.electricpower.com.cn/CN/Y2023/V56/I2/93

参考文献

[1] 郑宽, 徐志成, 鲁刚, 等. 高比例新能源电力系统演化进程中核电与新能源协调发展策略[J]. 中国电力, 2021, 54(7): 27–35
ZHENG Kuan, XU Zhicheng, LU Gang, et al. Coordinated development strategy for nuclear power and new energy in the evolution process of power system with high penetration of new energy[J]. Electric Power, 2021, 54(7): 27–35
[2] 单葆国, 冀星沛, 许传龙, 等. 近期全球能源供需形势分析及中国能源电力保供策略[J]. 中国电力, 2022, 55(10): 1–13
SHAN Baoguo, JI Xingpei, XU Chuanlong, et al. Recent situation of global energy supply-demand and guarantee strategy of China’s energy and power supply[J]. Electric Power, 2022, 55(10): 1–13
[3] 余子淳, 范宏, 夏世威. 计及电动公交车 V2G 响应的区域综合能源系统两阶段优化调度[J]. 中国电力, 2022, 55(7): 179–192
YU Zichun, FAN Hong, XIA Shiwei. Two-stage optimal scheduling of regional integrated energy system considering V2G response of electric buses[J]. Electric Power, 2022, 55(7): 179–192
[4] 刘林, 李苏秀, 张桦, 等. 能源互联网商业模式迭代体系与方法初探[J]. 中国电力, 2022, 55(1): 203–213
LIU Lin, LI Suxiu, ZHANG Hua, et al. Business model iteration system and method for energy internet[J]. Electric Power, 2022, 55(1): 203–213
[5] 古宸嘉, 王建学, 李清涛, 等. 新能源集中并网下大规模集中式储能规划研究述评[J]. 中国电力, 2022, 55(1): 2–12
GU Chenjia, WANG Jianxue, LI Qingtao, et al. Review on large-scale centralized energy storage planning under centralized grid integration of renewable energy[J]. Electric Power, 2022, 55(1): 2–12
[6] 王雨婷. 面向能源互联网的多端口双向能量路由器研究[D]. 北京: 北京交通大学, 2016.
WANG Yuting. Study on multi-port bi-directional energy router in energy internet[D]. Beijing: Beijing Jiaotong University, 2016.
[7] 易永辉, 任志航, 马红伟, 等. 分布式电源高渗透率的微电网快速稳定控制技术研究[J]. 电力系统保护与控制, 2016, 44(20): 31–36
YI Yonghui, REN Zhihang, MA Hongwei, et al. Study on fast stable control technology of high permeability micro-grid with distributed generation[J]. Power System Protection and Control, 2016, 44(20): 31–36
[8] 张释中, 裴玮, 杨艳红, 等. 基于柔性直流互联的多微网集成聚合运行优化及分析[J]. 电工技术学报, 2019, 34(5): 1025–1037
ZHANG Shizhong, PEI Wei, YANG Yanhong, et al. Optimization and analysis of multi-microgrids integration and aggregation operation based on flexible DC interconnection[J]. Transactions of China Electrotechnical Society, 2019, 34(5): 1025–1037
[9] 于国星, 宋蕙慧, 侯睿, 等. 柔性直流互联孤岛微网群的分布式频率协同控制[J]. 电力系统自动化, 2020, 44(20): 103–111
YU Guoxing, SONG Huihui, HOU Rui, et al. Distributed cooperative frequency control for flexible DC interconnected island microgrid cluster[J]. Automation of Electric Power Systems, 2020, 44(20): 103–111
[10] 田艳军, 彭飞, 王毅, 等. DC/AC并网变流器系统功率双向流动下稳定性差异分析与功率补偿控制[J]. 高电压技术, 2021, 47(9): 3303–3316
TIAN Yanjun, PENG Fei, WANG Yi, et al. Stability difference analysis and power compensation control for DC/AC grid-connected converter system under bidirectional power flow[J]. High voltage Engineering, 2021, 47(9): 3303–3316
[11] TIAN Y J, LOH P C, DENG F J, et al. Impedance coordinative control for cascaded converter in bidirectional application[J]. IEEE Transactions on Industry Applications, 2016, 52(5): 4084–4095.
[12] TIAN Y J, LOH P C, CHEN Z, et al. Impedance interactions in bidirectional cascaded converter[J]. IET Power Electronics, 2016, 9(13): 2482–2491.
[13] WU W H, CHEN Y D, ZHOU L M, et al. A virtual phase-lead impedance stability control strategy for the maritime VSC-HVDC system[J]. IEEE Transactions on Industrial Electronics, 2018, 14(12): 5475–5486.
[14] 陆维, 赵兴勇, 赵钰彬, 等. 孤网模式下交直流混合微电网互联变换器综合下垂控制[J]. 电测与仪表, 2020, 57(2): 101–108
LU Wei, ZHAO Xingyong, ZHAO Yubin, et al. Integrated droop control of AC/DC hybrid micro-grid interlinking converter in isolated network mode[J]. Electrical Measurement & Instrumentation, 2020, 57(2): 101–108
[15] 田艳军, 彭飞, 王慧, 等. 输电系统中并网变流器优化双向功率稳定性差异的阻抗控制策略[J]. 高电压技术, 2020, 46(11): 3734–3742
TIAN Yanjun, PENG Fei, WANG Hui, et al. Impedance control strategy for optimizing bidirectional power stability difference of grid-connected converters in transmission system[J]. High Voltage Engineering, 2020, 46(11): 3734–3742
[16] 姜玉霞, 田艳军, 李永刚. 背靠背变流器调节器参数及传输功率变化对阻抗稳定特性的影响及其改进控制策略[J]. 高电压技术, 2019, 45(9): 2866–2875
JIANG Yuxia, TIAN Yanjun, LI Yonggang. Influence of back-to-back converter regulator parameters and transmission power variation on impedance stability and improved control strategy[J]. High voltage Engineering, 2019, 45(9): 2866–2875
[17] AMIN M, MOLINAS M, LYU J, et al. Impact of power flow direction on the stability of VSC-HVDC seen from the impedance nyquist plot[J]. IEEE Transactions on Power Electronics, 2017, 32(10): 8204–8217.
[18] WEN B, BOROYEVICH D, BURGOS R, et al. Analysis of d-q small-signal impedance of grid-tied inverters[J]. IEEE Transactions on Power Electronics, 2016, 31(01): 675–687.
[19] 黄旭程, 何志兴, 伍文华, 等. 交直流微电网中变换器级联系统稳定性分析与协同控制[J]. 中国电机工程学报, 2019, 39(5): 1432–1443
HUANG Xucheng, HE Zhixing, WU Wenhua, et al. Stability analysis of converters cascade system in the hybrid AC/DC microgrid and coordinative control[J]. Proceedings of the CSEE, 2019, 39(5): 1432–1443
[20] WILDRICK C M, LEE F C, CHO B H, et al. A method of defining the load impedance specification for a stable distributed power system[J]. IEEE Transactions on Power Electronics, 1995, 10(3): 280–285.
[21] LEPPÄAHO J, HUUSARI J, NOUSIAINEN L, et al. Dynamic properties and stability assessment of current-fed converters in photovoltaic applications[J]. IEEE Transactions on Industry Applications, 2011, 131(8): 976–984.