中文摘要：

在LCL型光伏并网逆变器中，电流控制器的比例控制系数设计不合理易造成系统不稳定，甚至损坏逆变器。对采用逆变侧电感电流反馈的LCL型三相光伏并网逆变器进行数学建模，运用Routh-Huiwitz稳定性判据基于系统离散化模型进行稳定性分析，可求得比例控制系数的精确范围。分析逆变侧电感、滤波电容以及网侧电感的取值与比例控制系数的关系，探讨滤波电感和电容的取值对系统稳定性的影响。通过Matlab仿真及在50kW光伏逆变器实验平台上进行测试，验证了所进行的稳定性分析的正确性。

英文摘要：

The unreasonable design of proportional control coefficient of current controller is easy to lead to system instabili- ty or even damage of the photovohaic grid-connected inverter with LCL filter. A mathematical model of three-phase photovohaic grid inverter with LCL filter was established, which adopts inductive current feedback in inverter side. and then applies the Routh-Hurwitz stability criterion is used to analyze the stability of the inverter system on the basis of system discretization model, with which the precise range of proportional control coefficient can be derived. The relationship between values of the inverter side inductance, filtering capacitor and network side inductance, and proportional control coefficient is analyzed. The influence of filtering inductance and capacitance values on the system stability is discussed. The correctness of the stability analysis was demonstrated by the results of simulation with Matlab and test on a test-bed for 50 KW photovohaic grid-connected inverter.