多逆变器并网下的超高次谐振特性分析  

Analysis on Supraharmonic Resonance Characteristics with Integration of Multiple Inverters

作　　者：汪颖[1] 罗代军 肖先勇[1] 曹子恒 孙建风 WANG Ying;LUO Daijun;XIAO Xianyong;CAO Ziheng;SUN Jianfeng(College of Electrical Engineering,Sichuan University,Chengdu 610065,China)

机构地区：[1]四川大学电气工程学院

出　　处：《电力系统自动化》2020年第1期192-199,共8页Automation of Electric Power Systems

基　　金：国家自然科学基金资助项目(51807126)~~

摘　　要：超高次谐波是电力电子技术快速发展过程中不可避免的电能质量问题,受到了越来越多的关注。为揭示多个逆变器并网下的超高次谐振特性,文中提出了一种多逆变器并网下的超高次谐振特性分析方法。首先,以单相并网逆变器为例,分析其在单极倍频正弦脉宽调制(SPWM)下的谐波分布特性,以此来揭示基于单极倍频SPWM控制下的电力电子装置的超高次谐波发射机理。然后,建立了逆变器并网等效电路模型,并在此基础上,得到了多逆变器并网系统超高次谐波下的等效电路模型。其次,根据所建的等效电路模型求得了公共连接点的等效阻抗,并提出了超高次谐振放大系数的概念,在此基础上采用控制变量法分析了滤波器参数、并网逆变器数量和电网阻抗变化下系统的超高次谐振特性。最后,通过仿真验证了所建模型和理论分析的正确性。Supraharmonic is an inevitable power quality problem in the rapid development of power electronic technologies, which attracts more and more attention. In order to reveal the supraharmonic resonance characteristics with integration of multiple inverters, this paper proposes an analysis method of supraharmonic resonance characteristic. Firstly, taking the single-phase gridconnected inverter as an example, the supraharmonic distribution characteristics with the control of unipolar and frequency multiplication sinusoidal pulse width modulation(SPWM) are analyzed to reveal the supraharmonic emission mechanism of power electronic devices based on unipolar and frequency multiplication SPWM control. Secondly, an equivalent circuit model of gridconnected inverter is established. On this basis, the supraharmonic equivalent circuit model of multi-inverter grid-connected system is obtained. Thirdly, according to the equivalent circuit model, the equivalent impedance at the point of common coupling(PCC) is given, and the concept of supraharmonic resonance amplification factor is proposed. Then the control variable method is used to analyze the supraharmonic resonance characteristics of the grid-connected system when the filter parameters, the number of gridconnected inverters and the grid impedance change. Finally, the correctness of the model and theoretical analysis is verified by simulation.

关 键 词：超高次谐波 发射机理 LCL型并网逆变器 超高次谐振 等效电路 谐振放大系数 

分 类 号：TM464[电气工程—电器]