摘要
大规模光伏经串补并网系统存在次同步振荡失稳风险,传统研究一般基于负阻尼振荡理论对此进行解释.本文将因最大功率跟踪控制(MPPT)导致的光伏间谐波作为扰动源,大规模光伏经串补并网系统作为受迫系统,采用强迫振荡理论揭示光伏发电基于扰动式MPPT与串补并网系统相互作用的次同步振荡机制,并在PSCAD/EMTDC仿真平台进行验证.结果表明:基于扰动式MPPT的光伏逆变器因交直流侧的调制耦合作用向系统输出间谐波电流,当该间谐波频率与系统固有弱阻尼模式频率接近时,可能导致严重的强迫次同步振荡问题,对系统稳定性造成冲击;算例仿真验证了所提理论的正确性.
There exists the subsynchronous oscillation(SSO) instability risk in large-scale photovoltaic(PV) grid-connected systems with series compensation, which is generally explained by the negative damped oscillation theory. In this paper, the inter-photovoltaic harmonics due to maximum power point tracking(MPPT) control are used as the disturbance source and the large-scale PV grid-connected system with series compensation as the forced system. The forced oscillation theory is used to reveal the SSO mechanism of PV power generation based on the interaction between the perturbed MPPT and the series compensation grid-connected system, and verified in the PSCAD/EMTDC simulation platform. The results show that the perturbed MPPT-based PV inverter outputs interharmonic currents to the system due to the modulation coupling on the AC-DC side, which may lead to serious forced SSO problems when the interharmonic frequency is close to the frequency of inherent weakly damped mode of the system, causing a shock to the system stability. The simulation results verify the correctness of the proposed theory.
作者
林勇
康佳乐
余浩
陈鸿琳
杨彦霁
陈武晖
LIN Yong;KANG Jiale;YU Hao;CHEN Honglin;YANG Yanji;CHEN Wuhui(Grid Planning and Research Center,Guangdong Power Grid Co.,Ltd.,Guangzhou 510080,China;College of Electrical and Power Engineering,Taiyuan University of Technology,Taiyuan 030024,China;School of Electrical and Information Engineering,Jiangsu University,Zhenjiang 212013,Jiangsu,China)
出处
《上海交通大学学报》
EI
CAS
CSCD
北大核心
2022年第9期1118-1127,共10页
Journal of Shanghai Jiaotong University
基金
南方电网公司科技项目(037700KK52190013(GDKJXM 20198287))。
关键词
光伏
间谐波
次同步振荡
强迫振荡
photovoltaic(PV)
interharmonic
subsynchronous oscillation(SSO)
forced oscillation
