基于改进扰动观察法的光伏MPPT策略

Photovoltaic MPPT strategy based on improved perturbation and observation method

针对传统扰动观察法无法兼顾跟踪稳定性与快速性的问题,提出一种基于不确定性推理的扰动观察法,实现最大功率点跟踪(MPPT)。首先,建立光伏电池模型并验证其输出特性;其次,基于不确定性推理建立非线性扰动函数,同时引入光照、温度变化率对步长的扰动量进行修正;最后,通过MATLAB/SIMULINK仿真验证所提策略。结果表明:当光照强度或温度发生变化时,本文提出的算法的响应速度优于传统扰动观察法,且在MPP附近的功率震荡小,提高了跟踪稳定性与跟踪速度。

In view of the problem that the traditional perturbation and observation method cannot track stably and rapidly, an improved perturbation and observation method based on uncertainty reasoning is proposed to realize maximum power point tracking(MPPT). Firstly, the photovoltaic cell model is established and its output characteristics is verified. Secondly, the nonlinear perturbation function is established based on uncertainty reasoning, and the radiation intensities and temperature change rates are introduced to correct the perturbation of step length. Finally, the proposed strategies are verified by MATLAB/SIMULINK simulation. The results show that the response speed of the proposed algorithm in this paper is quicker than the traditional perturbation and observation method when the radiation intensity or temperature changes, and the power oscillation near the MPP is smaller. Thus, the tracking stability and system response speed are enhanced.