考虑频率突变影响的孤岛微电网系统建模和基于Lyapunov第二法的暂态稳定性分析

doi:10.19595/j.cnki.1000-6753.tces.L10069

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摘要

以电力电子变流器为主导的微电网作为一种灵活、可靠的分布式能源消纳和集成方式,近年来越来越受到关注。由于缺少电网稳定的电压和频率支撑,孤岛微电网在故障扰动下易出现暂态失稳现象。考虑锁相环受扰瞬间的被动频率突变和下垂控制器无功环影响,本文建立了由构网型和跟网型逆变器共同组成的孤岛微电网的改进暂态模型,改善了暂态模型精度。在此基础上,构建了一种二次型Lyapunov函数,用于孤岛微电网的暂态稳定性分析。通过待定系数,减小了非耗散区的影响,从而改善了传统Lyapunov方法的保守性。利用Lyapunov稳定判据,对不同形式扰动下的功角稳定边界进行了估计,分析了孤岛微电网对不同形式扰动的敏感度,揭示了系统参数对暂态稳定性的影响。最后,利用Matlab/Simulink仿真和基于RT-Lab的硬件在环实验对本文所提方法进行了验证。

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	李锡林
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关键词 ：并网逆变器, 孤岛微电网, 同步稳定性, 频率突变, Lyapunov稳定判据

Abstract：

As an effective and reliable distributed energy integration and consumption mode, converter-based microgrids can operate in grid-connected mode and islanded mode Due to the lack of stable voltage and frequency support, the islanded microgrid is prone to lose stability under fault disturbance. Besides, various converters with different control types interact with each other in the microgrid, making the system easier to lose stability. The interactions of GFL-VSC and GFM-VSC in the islanded microgrid system and their effects on system stability are rarely analyzed in the former studies. In addition, due to the negative damping characteristics of GFL-VSC, the analysis methods of the previous studies are quite conservative. A new Lyapunov analysis method based on quadratic form principle considering PLL frequency mutation effect is proposed in this paper, which provides a conservatively improved stability region estimation.
Firstly, a conventional second order nonlinear mathematical model of GFL-VSC parallel GFM-VSC system considering the effect of reactive power loop is established. Simulation comparison shows that the conventional model has some transient errors. Secondly, a passive frequency mutation effect widely exists in GFL-VSCs is revealed, which is caused by the proportional controller of PLL. By deducing a unified frequency mutation formula for different types of large disturbances, a modified model considering frequency mutation effect is obtained, which greatly improves the transient-state error of the existing conventional model. Third, considering the influence of reactive power loop on the output voltage of GFM-VSC, a new parametric Lyapunov function based on quadratic form theory is proposed. By undetermined coefficient, the obtained dissipation interval is larger than that of conventional Lyapunov function. Therefore, a less conservative estimation of the transient stable domain of islanded microgrid system can be obtained. The less-conservatism of the proposed method is mathematical proved. Fourthly, considering the frequency mutation effect and combining with the obtained stable domain, the power angle stability range corresponding to different disturbance forms is derived, and the conclusion is drawn that the sensitivity of the system to different disturbance forms is different. Fifth, from the point of view of physical mechanism, the influence of dynamic interaction between GFL-VSC and GFM-VSC on the stability of the islanded microgrid system is explored, and corresponding to the terms in the state space equation. Sixth, based on the proposed Lyapunov's method, the size of transient stable domain of the islanded microgrid system is derived and compared to analyze the influence of different network parameters and controller parameters on the stability of the islanded microgrid system. Finally, the proposed method is verified by MATLAB/Simulink simulation and the RT-Lab based hardware-in-loop experiments.
The following conclusions can be drawn from this paper: (1) The output frequency of the PLL will mutate due to the sudden change of voltage at the PCC when the converter is disturbed under large disturbance. Conventional modeling method ignore this phenomenon, which leads to transient model errors and potential misjudgment of stability. (2) Based on the different frequency mutation mechanism of different disturbances, the sensitivity of the islanded microgrid system to different forms of disturbances is different. The sensitivity order is voltage disturbance>current disturbance>inductance disturbance>phase disturbance. The higher the sensitivity, the more likely the system instability occurs. (3) The larger the voltage reference value, the stronger the system stability. The smaller the current reference value, droop coefficient and line inductance, the stronger the system stability will be. The influence of PLL’s parameters on the stability is more complex and not a monotonous relationship. The larger the reactive load and reactive droop coefficient, the worse the system stability.

Key words： Grid-connected inverter islanded microgrid synchronization stability frequency mutation Lyapunov stability criterion

收稿日期: 2023-01-09

PACS:

TM464

基金资助:

国家重点研发计划项目（2022YFB2402701）和国家自然科学基金青年项目（52007134）资助

通讯作者: 查晓明男,1967年生,博士,二级教授,博士研究生导师,研究方向为大功率电力电子装置等。E-mail：xmzha@whu.edu.cn

作者简介: 李锡林男,1999年生,博士研究生,研究方向为电力电子化电力系统暂态稳定性分析。E-mail：snplee@whu.edu.cn

引用本文:

李锡林, 查晓明, 田震, 黄萌, 胡宇飞. 考虑频率突变影响的孤岛微电网系统建模和基于Lyapunov第二法的暂态稳定性分析[J]. 电工技术学报, 0, (): 148-148. Li Xilin, Zha Xiaoming, Tian Zhen, Huang Meng, Hu Yufei. Modeling of Island Microgrid Considering Frequency Mutation and Transient Stability Analysis Based on Lyapunov Second Method. Transactions of China Electrotechnical Society, 0, (): 148-148.

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[1] 胡家兵, 袁小明, 程时杰. 电力电子并网装备多尺度切换控制与电力电子化电力系统多尺度暂态问题[J]. 中国电机工程学报, 2019, 39(18): 5457-5467, 5594.
Hu Jiabing, Yuan Xiaoming, Cheng Shijie.Multi-time scale transients in power-electronized power systems considering multi-time scale switching control schemes of power electronics apparatus[J]. Proceedings of the CSEE, 2019, 39(18): 5457-5467, 5594.
[2] 唐英杰,查晓明,田震,李翼翔,胡宇飞,万子镜.考虑非线性阻尼效应的孤岛微电网暂态稳定性分析及提升策略研究[J/OL].电源学报:1-11.
Tang Yinjie, Zha Xiaoming, Tian Zhen, et al.Transient Stability Analysis and Enhanced Control Strategy for Islanded Microgrid Considering Nonlinear Damping Effect[J/OL]. Journal of Power Supply:1-11.
[3] 周晖, 王跃, 李明烜, 等. 孤岛并联虚拟同步发电机暂态功率分配机理分析与优化控制[J]. 电工技术学报, 2019, 34(增刊2): 654-663.
Zhou Hui, Wang Yue, Li Mingxuan, et al.Analysis and optimal control of transient active power sharing between islanded parallel virtual synchronous generators[J]. Transactions of China Electrotechnical Society, 2019, 34(S2): 654-663.
[4] 涂春鸣, 邹凯星, 高家元, 等. 基于不对称正负反馈效应的PQ功率控制并网逆变器稳定性分析[J]. 电工技术学报, 2023, 38(2): 496-509.
Tu Chunming, Zou Kaixing, Gao Jiayuan, et al.Stability analysis of grid-connected inverter under PQ power control based on asymmetric positive-negative-feedback effects[J]. Transactions of China Electrotechnical Society, 2023, 38(2): 496-509.
[5] 许诘翊, 刘威, 刘树, 等. 电力系统变流器构网控制技术的现状与发展趋势[J]. 电网技术, 2022, 46(9): 3586-3595.
Xu Jieyi, Liu Wei, Liu Shu, et al.Current state and development trends of power system converter grid-forming control technology[J]. Power System Technology, 2022, 46(9): 3586-3595.
[6] 汪春江, 孙建军, 宫金武, 等. 并网逆变器与电网阻抗交互失稳机理及阻尼策略[J]. 电工技术学报, 2020, 35(增刊2): 503-511.
Wang Chunjiang, Sun Jianjun, Gong Jinwu, et al.Mechanism and damping strategy of interactive instability between grid-connected inverter and grid impedance[J]. Transactions of China Electrotechnical Society, 2020, 35(S2): 503-511.
[7] 李锡林, 唐英杰, 田震, 等. 基于改进等面积法则的并网逆变器同步稳定性分析[J]. 电力系统自动化, 2022, 46(18): 208-215.
Li Xilin, Tang Yingjie, Tian Zhen, et al.Synchronization stability analysis of grid-connected inverter based on improved equal area criterion[J]. Automation of Electric Power Systems, 2022, 46(18): 208-215.
[8] Tian Zhen, Tang Yingjie, Zha Xiaoming, et al.Hamilton-based stability criterion and attraction region estimation for grid-tied inverters under large-signal disturbances[J]. IEEE Journal of Emerging and Selected Topics in Power Electronics, 2022, 10(1): 413-423.
[9] Fu Xikun, Sun Jianjun, Huang Meng, et al.Large-signal stability of grid-forming and grid-following controls in voltage source converter: a comparative study[J]. IEEE Transactions on Power Electronics, 2021, 36(7): 7832-7840.
[10] Li Xilin, Tian Zhen, Zha Xiaoming, et al. An iterative equal area criterion for transient stability analysis of grid-tied converter systems with varying damping[J]. IEEE Transactions on Power Systems, 1079, PP(99): 1-13.
[11] Shuai Zhikang, Shen Chao, Liu Xuan, et al.Transient angle stability of virtual synchronous generators using Lyapunov’s direct method[J]. IEEE Transactions on Smart Grid, 2019, 10(4): 4648-4661.
[12] 黄林彬, 章雷其, 辛焕海, 等. 下垂控制逆变器的虚拟功角稳定机理分析[J]. 电力系统自动化, 2016, 40(12): 117-123, 150.
Huang Linbin, Zhang Leiqi, Xin Huanhai, et al.Mechanism analysis of virtual power angle stability in droop-controlled inverters[J]. Automation of Electric Power Systems, 2016, 40(12): 117-123, 150.
[13] He Changjun, He Xiuqiang, Geng Hua, et al.Transient stability of low-inertia power systems with inverter-based generation[J]. IEEE Transactions on Energy Conversion, 2022, 37(4): 2903-2912.
[14] He Xiuqiang, Geng Hua.PLL synchronization stability of grid-connected multiconverter systems[J]. IEEE Transactions on Industry Applications, 2022, 58(1): 830-842.
[15] Yi Xiangtong, Peng Yelun, Zhou Quan, et al.Transient synchronization stability analysis and enhancement of paralleled converters considering different current injection strategies[J]. IEEE Transactions on Sustainable Energy, 2022, 13(4): 1957-1968.
[16] 李翼翔, 田震, 唐英杰, 等. 考虑构网型与跟网型逆变器交互的孤岛微电网小信号稳定性分析[J]. 电力自动化设备, 2022, 42(8): 11-18.
Li Yixiang, Tian Zhen, Tang Yingjie, et al.Small-signal stability analysis of island microgrid considering interaction between grid-forming converter and grid-following converter[J]. Electric Power Automation Equipment, 2022, 42(8): 11-18.
[17] 王雪梅, 王艺博, 刘雨桐, 等. 基于虚拟电抗的主动支撑型新能源机组低电压穿越控制方法[J]. 电网技术, 2022, 46(11): 4435-4444.
Wang Xuemei, Wang Yibo, Liu Yutong, et al.Low voltage ride-through control of actively-supported new energy unit based on virtual reactance[J]. Power System Technology, 2022, 46(11): 4435-4444.
[18] 刘航, 王跃, 刘永慧, 等. 基于定量设计虚拟阻抗的VSG低电压穿越策略[J]. 高电压技术, 2022, 48(1): 245-256.
Liu Hang, Wang Yue, Liu Yonghui, et al.The LVRT strategy for VSG based on the quantitatively designed virtual impedance[J]. High Voltage Engineering, 2022, 48(1): 245-256.
[19] Li Mingfei, Quan Xiangjun, Wu Zaijun, et al.Modeling and transient stability analysis of mixed-GFM-GFL-based power system[C]//2021 IEEE Sustainable Power and Energy Conference (iSPEC), Nanjing, China, 2022: 2755-2759.
[20] Sun Huiqiang, Lin Xinchun, Chen Songbai, et al.Transient stability analysis of the standalone solar-storage AC supply system based on grid-forming and grid-following converters during sudden load variation[J]. IET Renewable Power Generation, 2022, 66: 1.
[21] Hu Qi, Fu Lijun, Ma Fan, et al.Large signal synchronizing instability of PLL-based VSC connected to weak AC grid[J]. IEEE Transactions on Power Systems, 2019, 34(4): 3220-3229.
[22] 廖书寒, 查晓明, 黄萌, 等. 适用于电力电子化电力系统的同调等值判据[J]. 中国电机工程学报, 2018, 38(9): 2589-2598, 2827.
Liao Shuhan, Zha Xiaoming, Huang Meng, et al.Coherency criterion applicable to power electronics dominated large power systems[J]. Proceedings of the CSEE, 2018, 38(9): 2589-2598, 2827.
[23] 查晓明, 张扬, 成燕, 等. 用于简化微电网结构的微分几何广义同调方法[J]. 电工技术学报, 2012, 27(1): 24-31.
Zha Xiaoming, Zhang Yang, Cheng Yan, et al.New method of extended coherency for micro-grid based on homology in differential geometry[J]. Transactions of China Electrotechnical Society, 2012, 27(1): 24-31.
[24] Khalil H K.Nonlinear systems[M]. 3rd ed. Upper Saddle River, NJ: Prentice Hall, 2002
[25] Liu Yushuang, Huang Meng, Tse C K, et al.Stability and multiconstraint operating region of grid-connected modular multilevel converter under grid phase disturbance[J]. IEEE Transactions on Power Electronics, 2021, 36(11): 12551-12564.
[26] Tian Xinshou, Wang Weisheng, Li Xiang, et al.Fault ride through strategy of DFIG using rotor voltage direct compensation control under voltage phase angle jump[J]. CSEE Journal of Power and Energy Systems, 2019, 5(4): 515-523.