二次型升压变换器光伏系统MPPT研究

Maximum Power Point Tracking Research Based on Quadratic Boost Converter

随着光照强度和环境温度的变化,光伏电池的最大功率点(MPP)也随之改变。为了实现光伏系统最大功率点跟踪(MPPT),把二次型升压变换器应用于光伏系统最大功率点跟踪电路,它能在低占空比下获得高的电压变比。然后设计了二次型升压变换器的控制方法——改进的变步长干扰观测法控制策略,在系统计算量增加不大的前提下,有效地减小了稳态时功率振荡,在稳态运行状态下的功率追踪效率最高可达到99.50%。最后,通过仿真实验验证了理论分析的正确性。

With the change of light intensity and ambient temperature,the maximum power point（MPP）of photovoltaic systems has changed. In order to achieve the maximum power point tracking（MPPT）of photovoltaic systems,quadratic Boost converter was adopted to track the maximum power point of photovoltaic systems,which provided high voltage conversion ratio with lower duty cycle. The control method of quadratic Boost inverter——the improved variable steps perturbation and observation（PO）control strategy was designed,the output power oscillation of the converter was effectively reduced by little increase in system calculation,the steady state maximum power point tracking efficiency of the proposed system was obtained as 99.50%. Finally,the correctness of theoretical analysis was validated by simulations.