一种基于VSG控制的光伏电站对多机系统的低频振荡自适应控制策略  

An adaptive low frequency oscillation control strategy of VSG-based photovoltaic power plants to multi-machine power systems

作　　者：周昕怡 成庶[1] 伍珣 饶新亮 刘畅 赵俊栋 ZHOU Xinyi;CHEN Shu;WU Xun;RAO Xinliang;LIU Chang;ZHAO Jundong(School of Transportation Engineering,Central South University,Changsha 410083,China;State Grid Changsha Electric Power Company,Changsha 410035,China)

机构地区：[1]中南大学交通运输工程学院,湖南长沙410083 [2]国网长沙供电公司,湖南长沙410035

出　　处：《中南大学学报（自然科学版）》2022年第8期2920-2931,共12页Journal of Central South University:Science and Technology

基　　金：国家重点研发计划项目(2016YFB1200601)。

摘　　要：虚拟同步发电机(virtual synchronous generator,VSG)技术在引入虚拟惯性与虚拟阻尼以提高系统稳定性的同时也继承了传统同步发电机的振荡特性,从而引起新的振荡。针对该问题,首先采用模式分析法与特征值分析法分别对VSG接入四机两区系统前后振荡模式的变化以及VSG主要参数对系统低频振荡的影响进行分析。通过提高虚拟阻尼和减少虚拟惯性的方式提高区间振荡的阻尼比,从而使弱阻尼的区间振荡表现出局部振荡的高阻尼特性。在此基础上,采用基于广域信号控制的自适应虚拟惯性和广域阻尼稳定器的综合控制策略。以联络线上的功率监测信号作为控制输入,通过自适应虚拟惯性控制器与广域阻尼稳定器调整区间振荡阻尼以抑制联络线上的功率低频振荡,并通过DIgSILENT仿真对本方法进行验证。研究结果表明:该方法可以有效缩短低频振荡的持续时间,减少振荡的超调量,增强系统的稳定性。The virtual synchronous generator(VSG) technology brings virtual inertia and virtual damping to improve the stability of the system. It also inherits oscillation characteristics of traditional synchronous generators,causing the new oscillation. Focusing on the problem, the oscillation mode change before and after the VSG was connected to the two-area system and the influence of main parameters in VSG on the low-frequency oscillation of the system were studied through the analysis of mode and feature values. The damping ratio of the interval oscillation was improved by increasing the virtual damping and decreasing the virtual inertia, and the weakly damped interval oscillation had the high damping of local oscillation. On the basis, a comprehensive control strategy of adaptive virtual inertia and wide-area damping stabilizer based on wide-area signal was utilized. The power monitoring signal of the tie line was used as the input, and the damping of the interval oscillation was adjusted by the adaptive virtual inertia controller and the wide-area damping stabilizer. Thus, the low-frequency oscillation of power on the tie line was suppressed. Finally, the proposed strategy was verified by DIgSILENT simulation. The results show that it effectively reduces both the time of low-frequency oscillation and overshoot of oscillation, enhances the stability of the system.

关 键 词：虚拟同步发电机 低频振荡 模式分析 阻尼 自适应 广域阻尼稳定器 

分 类 号：TM71[电气工程—电力系统及自动化]