Abstract:With the increase in the proportion of new energy generation, the inertia of power system decreases. A virtual synchronous machine can provide inertia for the power system. At present, most of the parameter configuration of the virtual inertia is analyzed from the perspective of small-signal or frequency stability. These two factors have been simultaneously considered by a few studies to conduct virtual inertia configuration. Moreover, research on the configuration of virtual inertia mainly focuses on the voltage-source virtual synchronous machine, while a current-source virtual synchronous machine is rarely studied. To solve this problem, the influence of virtual inertia parameters on the small-signal stability and frequency stability is analyzed by establishing synchronous dominant loop models for voltage-source and current-source virtual synchronous machines. Results show that the small-signal stability of the system can be improved by decreasing the virtual inertia. However, under power perturbation, the output frequency of the current-source virtual synchronous machine will superimpose the transient component of Vq dominated by the virtual inertia, resulting in overshoot. If the virtual inertia parameter is too small, the frequency will not meet the grid-connected operation standard. Based on this, for the system to simultaneously exhibit good small-signal stability and frequency stability, the configuration of virtual inertia needs to be restricted by the two kinds of stability. Finally, the conclusion of this study is verified through the simulation of the inertia configuration of a single infinite machine system and an island two-machine system.
[1] 张栋凯, 陈羽飞, 姜婷玉, 等. 电力系统的电力电子化趋势分析与探讨[J]. 河海大学学报(自然科学版), 2020, 48(4):377-384. ZHANG D K, CHEN Y F, JIANG T Y, et al. Analysis and discussion of electronization trend of power system[J]. Journal of Hohai University(Natural Sciences), 2020, 48(4):377-384. (in Chinese) [2] SUBUDHI B, PRADHAN R. A comparative study on maximum power point tracking techniques for photovoltaic power systems[J]. IEEE Transactions on Sustainable Energy, 2013, 4(1):89-98. [3] HE W, YUAN X M, HU J B. Inertia provision and estimation of PLL-based DFIG wind turbines[J]. IEEE Transactions on Power Systems, 2017, 32(1):510-521. [4] MORREN J, DE HAAN S W H, KLING W L, et al. Wind turbines emulating inertia and supporting primary frequency control[J]. IEEE Transactions on Power Systems, 2006, 21(1):433-434. [5] 孙华东, 王宝财, 李文锋, 等. 高比例电力电子电力系统频率响应的惯量体系研究[J]. 中国电机工程学报, 2020, 40(16):5179-5192. SUN H D, WANG B C, LI W F, et al. Research on inertia system of frequency response for power system with high penetration electronics[J]. Proceedings of the CSEE, 2020, 40(16):5179-5192. (in Chinese) [6] 陶骞, 陶亮, 崔一铂, 等. 虚拟同步发电机动态特性参数分析及配置方法研究[J]. 电测与仪表, 2019, 56(21):8-15, 87. TAO Q, TAO L, CUI Y B, et al. Analysis of dynamic characteristic parameters and research on its configuration methods of virtual synchronous generator[J]. Electrical Measurement & Instrumentation, 2019, 56(21):8-15, 87. (in Chinese) [7] 王淋, 巨云涛, 吴文传, 等. 面向频率稳定提升的虚拟同步化微电网惯量阻尼参数优化设计. 中国电机工程学报.. DOI:10.13334/j.0258-8013.pcsee.201075. WANG L, JUN Y T, WU WC, et al. Optimal design of inertia and damping parameters of virtual synchronous microgrid for improving frequency stability. Proceedings of the CSEE.. DOI:10.13334/j.0258-8013.pcsee.201075. (in Chinese) [8] 黄林彬, 辛焕海, 黄伟, 等. 含虚拟惯量的电力系统频率响应特性定量分析方法[J]. 电力系统自动化, 2018, 42(8):31-38. HUANG L B, XIN H H, HUANG W, et al. Quantified analysis method of frequency response characteristics for power systems with virtual inertia[J]. Automation of Electric Power Systems, 2018, 42(8):31-38. (in Chinese) [9] HUANG L B, XIN H H, LI Z Y, et al. Grid-synchronization stability analysis and loop shaping for PLL-based power converters with different reactive power control[J]. IEEE Transactions on Smart Grid, 2020, 11(1):501-516. [10] 黄林彬. 高比例电力电子装备电力系统的同步稳定分析与控制设计[D]. 杭州:浙江大学, 2020. HUANG L B. Synchronization stability and control of power systems with high-penetration power electronics[D]. Hangzhou:Zhejiang University, 2020. (in Chinese) [11] SKOGESTAD S, POSTLETHWAITE I. Multivariable feedback control[M]. New York, NY, USA:Wiley, 1996. [12] 黄林彬, 辛焕海, 鞠平, 等. 电力电子并网装备的同步稳定分析与统一同步控制结构[J]. 电力自动化设备, 2020, 40(9):10-25. HUANG L B, XIN H H, JU P, et al. Synchronization stability analysis and unified synchronization control structure of grid-connected power electronic devices[J]. Electric Power Automation Equipment, 2020, 40(9):10-25. (in Chinese) [13] 孙扬声. 自动控制理论[M]. 北京:中国电力出版社, 2007. SUN Y S. Automatic control theory[M]. Beijing:China Electric Power Press, 2007. (in Chinese) [14] 胡寿松. 自动控制原理[M]. 北京:科学出版社, 2007. HU S S. Automatic control theory[M]. Beijing:Science Press, 2007. (in Chinese) [15] 陈珩. 电力系统稳态分析[M]. 北京:中国电力出版社, 2007. CHEN H. Power system steady state analysis[M]. Beijing:China Electric Power Press, 2007. (in Chinese)