中文摘要：

研究了两级式三相光伏并网发电系统的小干扰稳定性．建立了完整的小信号模型，包含光伏阵列出口侧稳压电容、Boost电路、L滤波器、MPPT控制器和并网逆变控制器．基于PSCAD／EMTDC的仿真模型，利用特征值分析法研究了系统的小干扰稳定性，计算了控制器参数变化时的系统特征值轨迹，据此调整控制器参数．小信号分析与仿真结果表明，合理调整控制器参数，可以提高系统的小干扰稳定性．

英文摘要：

The small-signal stability of a two-stage three-phase grid-connected PV system is analyzed by means of eigenvalues analysis. A complete small-signal model of the system including voltage stabilizing capacitor, Boost circuit, L filter, MPPT controller and controller for grid- connected inverter is developed. The eigenvalues traces as the controller＇ s parameters variation are calculated, according to which the controller＇ s parameters are adjusted. Additionally, a simulation model of the system based on PSCAD/EMTDC is built. The small-signal analysis and the simulation results show that reasonable adjusting of the controller＇ s parameters can improve the small-signal stability of the system.