基于模糊PI控制的光伏直流变换器控制策略研究

Study on The Control Strategy of Photovoltaic Dc Converter Based on Fuzzy PI Control

摘要:

以光伏发电系统模型为基础,把直流变换器中的Boost电路作为研究对象,先分别采用占空比恒定的定脉宽调制和占空比可调节的传统PI控制作为控制方法,利用MATLAB/Simulink仿真工具搭建光伏发电系统的主电路模型,进而分别根据不同的控制方法对Boost电路进行仿真分析。由仿真分析得到,定脉宽调制控制和传统PI控制的参数设置均无法适应实际工况的变化。基于此,提出一种模糊PI控制算法,通过对传统PI控制的参数设定进行实时调整,改善Boost电路的输出电压,使系统能更好地克服实际运行工况变化带来的不利影响。通过仿真分析可得,模糊PI控制的鲁棒性增强,并且能够降低系统的输出电压超调,缩短系统的稳定时间,提升系统的抗干扰能力。

Abstract:

On the basis of photovoltaic power generation system model, the Boost of the dc converter circuit as the research object, first duty ratio were used respectively to a constant pulse width modulation and adjustable duty ratio as the traditional PI control algorithm, using MATLAB/Simulink tool to build the main circuit model, which respectively according to different control methods to Boost circuit simulation analysis. Through simulation analysis, it is found that the parameter Settings of fixed pulse width modulation (PWM) control and traditional PI control cannot adapt to the changes of actual working conditions. Based on this, a fuzzy PI control algorithm is proposed to improve the output voltage of Boost circuit by adjusting the parameters of PI control in real time, so that it can better overcome the adverse influence brought by the change of actual operating conditions. Through simulation analysis, fuzzy PI control can reduce the output voltage overshoot, shorten the system stability time and improve the anti-interference ability of the system.