基于最大功率跟踪控制的单相光伏系统研究

Research on single-phase photovoltaic system based on MPPT control

分析光伏电池的特性,针对光伏电池输出功率随外界温度和日照强度而变化的特点,提出了采用模糊逻辑控制的最大功率跟踪策略,通过调节电路中功率开关管的占空比实现阻抗匹配,从而使光伏电池的输出功率最大化,并使系统运行于最佳工作点。在MATLAB平台上搭建基于模糊逻辑最大功率跟踪策略的光伏系统仿真模型,仿真结果表明:在外界环境稳定时,光伏电池的输出电压、电流及功率均可平稳保持在所期望的理论最佳值;在外界环境变化时,光伏电池的输出量经过短暂的恢复时间后仍可以跟踪在最优值,具备良好的动静态性能,验证了光伏系统仿真模型的正确性和控制策略的可靠性。

The characteristics of photovoltaic （PV） were analyzed in detail, and a maximum power point tracking （MPPT） method with fuzzy logic controller was proposed according to the fact that the output power of PV varied along with environment temperature and sunshine conditions. Impedance matching could be realized by regulating the duty ratio of power switch in BOOST converter to optimize the PV electdc power, and improve the system operation capability. Simulation models of PV system with fuzzy logic MPPT control scheme proposed were established based on MATLAB platform. The results testify the correctness of PV system models and reliability of the MPPT strategy by showing that PV outputs can follow the theoretical maximum values at stable conditions or variable working situation with transient recovery time, therefore excellent static and dynamic performance can be obtained.