直流微电网光伏发电最大功率点追踪方法

摘要

基于直流微电网母线电压稳定的实际情况,获得光伏电源电压和直流变换器占空比的函数关系,把占空比作为输入变量,在仅需测量光伏电源电流的基础上对其准确实施最大功率点追踪;可省略光伏发电直流微电网中众多分布式光伏电源端电压传感器及其相关电路,减少干扰,提高可靠性,降低系统成本.MATLAB下系统模型仿真和样机试验证明了所提控制方法的正确性与可行性.%MPPT(Maximum Power Point Tracking) is normally applied to photovoltaic system of DC microgrid and traditional method is to directly measure the real-time voltage and current by sensors. Since the bus voltage of DC microgrid is actually stable,the functional relationship between the photovoltaic voltage and the duty cycle of DC-DC converter can be obtained. A method of MPPT is proposed,which takes the duty cycle as the input variable and only measures the photovoltaic current,a number of voltage sensors and associated circuitry being cancelled. It reduces the interference and system cost and improves the system reliability. Simulation with MATLAB and experiment with prototype prove the correctness and validity of the proposed method.