带恒功率负载的光伏-储能混合发电系统非线性行为分析

Nonlinear Analysis of Photovoltaic Battery Hybrid Power System with Constant Power Loads

由于光伏-储能混合发电系统存在多种工作模式以及负载变换器的恒功率特性,系统在多个模式下出现不稳定性运行行为。首先识别系统中的霍普分岔和灾难性分岔的不稳定现象;然后通过建立系统开关平均模型,结合大信号分析,解析性地给出了系统非线性分岔行为的物理机理;最后通过计算和电路仿真,给出了保证实际系统能够稳定运行的参数变化范围。实验结果验证了分岔分析和稳定区域的正确性。

Due to the multiple operating modes of the photovoltaic-battery hybrid power system and constant power characteristic of load converters,there could be various instabilities in the system under different modes. In this paper,the instability phenomena of Hopf bifurcation and catastrophic bifurcation are identified in this kind of system firstly. Then,the physical origin of the nonlinear dynamics are analytically found by applying the switching averaged modeling and the large-signal analysis. The stability regions of the system parameters are given by mathematical calculation and circuit simulation. The validity of bifurcation analysis and the stability regions are verified by experimental works.