摘要
电网阻抗的存在可能引发光伏并网逆变器的谐波谐振,甚至不稳定。通过建立单相光伏并网逆变器的等效阻抗模型和等效控制模型,分析系统稳定性和谐振的关系,指出当光伏并网逆变器处于临界稳定状态时,系统由于阻抗匹配而出现谐振现象,且阻抗匹配的频率为系统开环截止频率。为降低并网电流中的谐波含量,应使光伏并网逆变器始终具有足够的稳定裕度,为此提出了“坚强的”光伏并网逆变器设计方案,且给出了详细的设计步骤。仿真和实验结果表明,所提的光伏并网逆变器能够输出较高质量的并网电流,其对电网阻抗具有很强适应性。
The grid-connected PV inverter may arise harmonic resonance and even be unstable because of the grid impedance. In this paper, the equivalent impedance model and equivalent control model of PV grid-connected inverter have been established, and through which the stability and resonance has been analyzed in detail. When the inverter is in critical stable state, the resonance occurs due to the impedance matching, and the impedance matching frequency is the system cutoff frequency. In order to reduce the harmonic content of the grid current and guarantee the inverter with enough stability margin, a "strong" PV grid-connected inverter has been proposed, and the design procedures have also been presented. Finally, the simulation and experiment have verified that the proposed grid-connected PV inverter can output high quality grid current, and has high adaptability to grid impedance.
作者
解宝
周林
郝高锋
谢星宇
郑堃
XIE Bao;ZHOU Lin;HAo Gaofeng;XIE Xingyu;ZHENG Kun(State Key Laboratory of Power Transmission Equipment&System Security and New Technology(Chongqing University),Shapingba District,Chongqing400044,China)
出处
《中国电机工程学报》
EI
CSCD
北大核心
2018年第22期6662-6670,共9页
Proceedings of the CSEE
基金
国家自然科学基金项目(51477021)~~
关键词
光伏并网逆变器
等效阻抗模型
等效控制模型
稳定性与谐振分析
grid-connected PV inverter
equivalent impedance model
equivalent control model
stability and resonance analysis
