一种光伏MPPT模糊控制算法研究

A PHOTOVOLTAIC MPPT FUZZY CONTROLLING ALGORITHM

针对太阳能光伏阵列的工作特性,在现有最大功率跟踪控制方法的基础上,提出了一种光伏MPPT的模糊控制算法——变步长扰动观察法。从偏差和偏差变化率的角度,将寻优分为二个阶段(第一阶段应用扰动观察法并设置较大步长快速接近最大功率点附近,第二阶段采用变步长的方法向最大功率点进一步逼近并至最佳),实现了光伏系统快速和高精度的跟踪要求。系统中引入了工作状态的判断环节,可以根据环境的变化,做出相应反应,提高了系统的快速跟踪性能和稳定性。

According to the characteristics of photovohaic （PV） array and the prevailing maximum power tracking control methods, a controlling algorithm of the maximum power point tracking （MPPT） based on the fuzzy algorithm, variable step-size perturbation observing, was proposed in this paper. The method is divided into two stages in the view of the error and the error rate of the system, the first step is to apply perturb and observe （P＆O）-arithmetic which sets up a larger step-size and get close to the maximum power point as fast as possible. On this basis, the second step is to utilize the variable step-size to close the maximum power point as precise as possible and get the optimum. The estimating of the working status, which can respond to the variance of the environment, was introduced into the system, and the fast tracking performance and the stability in photovohaic system were inproved.