中文摘要：

微电网系统中的并联接口逆变器通常采用电感-电容-电感（LCL）滤波器接入公共交流母线。该文分析了并联逆变器系统中LCL滤波器的谐振频率分布情况，并和传统的单逆变器系统LCL滤波器谐振频率分布特点进行了比较。理论结果显示：和传统的单逆变器系统相比，并联系统中出现了额外的谐振尖峰，且谐振频率随着网侧电感取值的变化发生偏移。理论分析表明：上述谐振频率的改变由滤波器无源网络变化引起。仿真和实验结果验证了该谐振峰值的存在。

英文摘要：

Parallel interface power electronic inverters in microgrid systems are usually connected to a common AC bus through LCL filters. The resonance frequency characteristics of such LCL filters in a parallel inverter system were analyzed here with the frequency domain analysis result for the parallel system compared to that in a conventional single inverter system. An additional resonance peak is found in the parallel system with the corresponding resonance frequency shifted by changes in the grid inductance. The peaks are related to changes in the passive network composed of the parallel LCL filters. The theoretical analyses are validated by both simulations and experimental results.