变论域模糊PID控制在微电网MPPT中的研究

针对微电网中光伏系统具有非线性、数学模型不确定的特点,分析了现有光伏电池最大功率点跟踪(MPPT)控制方法的优点和不足,采用变论域的思想,应用了变论域模糊PID算法,设计了实现MPPT的二级模糊控制器.由第一级模糊控制器确定输入论域伸缩因子来改变第二级模糊控制器的输入论域,并在MATLAB/Simulink中搭建仿真模型.仿真结果表明,变论域模糊PID控制能够快速、准确地跟踪光伏电池的最大功率点,基本消除了振荡现象,提高了光伏电池的工作效率和系统稳定性.

Study of MPPT in Micro-Grid Based on Variable Universe Fuzzy PID Control

In the light of the situation that the photovoltaic system in micro-grid is nonlinear and uncertainty, the photovohaic cell MPPT control methods in the strengths and weaknesses was analysed. Based on the idea of variable universe method,the theory of variable universe fuzzy PID algorithm was put forward, and a variable universe fuzzy controller with two grades was designed. The input universe stretching factor was produced by the first grade fuzzy controller; it was utilized to change the universe of the second grade fuzzy controller, and the simulation circuit was built in the MATLAB. The simulation results show that the method of variable universe fuzzy PID control can rapidly and accurately track the maximum power point of photovoltaic cells, avoid oscillation, and improve the work efficiency of the photovohaic cell and system stability.