光伏电池输出电压的稳定性分析

在光伏系统中,光伏电池以及相应的变换器均表现出非线性的特征,从而给控制系统的设计带来很大困难.本文分别选用Buck以及Boost变换器,对最大功率跟踪模式下光伏变换系统中光伏电池输出电压的稳定性,进行了频域内分析；针对传统的Boost变换器在光伏电池的宽电压输出范围内,难以维持稳定输出的特性,提出采用三态Boost变换器代替传统的Boost变换器,进行光伏电池输出电压的控制,理论分析表明,所采用的三态Boost变换器能够有效拓宽光伏电池输出稳定电压的范围、提高光伏系统的稳定性.仿真结果进一步证实了以上结论的正确性.

Stability analysis of photovoltaic cells output voltage

In the photovoltaic system,photovoltaic cells and the corresponding converters demonstrates the nonlinear and time-varying characteristics,which brings much difficulties to the control of the system.Based on the analysis of the photovoltaic cells and the converters commonly used in the system,this paper has an analysis on the stability of the output voltage of the Buck and Boost PV conversion system under the input voltage control mode.As the traditional Boost converter can’t maintain steady output in the wide output range of the PV cells,the tri-state Boost converter was proposed to replace the traditional Boost converter for the control of the output voltage in this paper.Theoretical analysis shows that the tri-state Boost converter can effectively broaden the range of steady output voltage and improve the stability of PV system.Finally,the simulation results further confirm the correctness of the above conclusions.