基于模糊控制的变步长电导增量法的最大功率点跟踪策略

Fuzzy control based variable step conductance increment method for maximum power point tracking strategy

为克服传统定步长算法无法兼顾跟踪速度和控制精度的问题,提出一种基于模糊控制的变步长电导增量算法。该算法将功率-电压变化量的微分(dPdU)和设定的恒定步长作为模糊控制器的输入,输出为变化的扰动步长,然后将其作为电导增量法的步长,实现扰动步长的自适应调整,达到快速性和精确性的统一。最后在Matlab中进行光伏系统仿真建模,并将该方法与另外两种传统改进的扰动观察法和电导增量法进行仿真对比,验证所提算法的有效性。结果表明:基于模糊控制的变步长电导增量法相比传统改进算法兼顾了跟踪速度和控制精度,有更高的平均输出功率且功率振荡范围更小,有助于减小功率损耗,改善了光伏系统动态静态工作性能。

Since the traditional fixed-step algorithms fail to give consideration to both tracking speed and control precision,a variable step conductance increment algorithm based on fuzzy control is proposed. In this algorithm,differential of power-voltage variation(d P d U)and the set constant step are taken as the input of the fuzzy controller,and the output is the varying disturbance step,which is then taken as the step size of conductance increment method to realize the adaptive adjustment of disturbance step and achieve the unity of rapidity and accuracy. The simulation modeling of photovoltaic system was carried out in Matlab. The proposed method was contrasted with the other two traditional improved methods named perturbation and observation method and conductance increment method to verify its effectiveness. The results show that the variable-step conductance increment method based on fuzzy control has satisfied tracking speed and control accuracy,higher average output power and smaller power oscillation range in comparison with the traditional improved algorithms,so it is helpful to reduce power loss and improve the dynamic and static working performance of photovoltaic system.