中文摘要：

当越来越多的并网逆变器连接到电网的同一公共连接点时,逆变器与电网之间的谐波交互作用对系统的稳定可靠运行是一个潜在威胁。根据电路理论,首先对阻抗网络的谐波谐振产生机理进行分析。为建立更加逼近实际并网系统的逆变器输出阻抗模型,提出将死区效应和开关器件非理想特性考虑到模型中来增加其精确性,并以LCL型滤波器双闭环控制系统为例做详细的模型推导。利用提出的输出阻抗模型,对多个并网逆变器与电网组成的分布式阻抗网络进行建模及谐波交互分析。仿真结果验证了所提出建模方法和谐波交互分析方法的正确性和有效性。

英文摘要：

Harmonic interaction between the grid-connected inverters and the utility grid may be introduced when more and more inverters were coupled to a same point of common coupling （PCC）, which was a potential risk for stable and effective operation of distributed power generation systems. Mechanisms of the harmonic resonance in distributed impedance networks were firstly analyzed in terms of electric circuit theories in this paper. To increase the accuracy of the proposed model, the dead-time effects and nonlinear characteristics of switching devices were modeled and incorporated into the developed model. For analyzing the harmonic interaction, an output-impedance based model of single-phase grid-connected inverters with the LCL filter based on a dual-loop control scheme was proposed. Based on the developed model, the harmonic interaction of multiple inverters with the grid was modeled and analyzed. Simulation results are presented to demonstrate the effectiveness of the modeling method and the harmonic interaction analysis method.