基于扰动观察法的光伏发电系统MPPT控制策略

Control Strategy of MPPT of Photovoltaic System Based on Perturbation and Observation Method

由于光伏电池的输出功率受到光照、温度等外界因素的影响,具有非线性特性。为了提高光伏发电系统的效率必须对其输出功率进行跟踪控制。在详细分析光伏电池等效电路及输出特性的基础上,利用Matlab/Simulink平台建立了光伏系统的仿真模型,阐述了最大功率跟踪(Maximum Power Point Tracking,MPPT)控制原理,重点研究了电压型扰动观察法的实现算法,通过MPPT控制器比较前后两次的功率大小来决定光伏电池的电压扰动方向,使光伏电池最终达到最大功率点。最后对整个光伏系统进行仿真试验,仿真结果表明在光照发生改变时,MPPT控制器能够及时调节,实现最大功率点跟踪,验证了光伏系统仿真模型的正确性和控制策略的可靠性。

Due to the output power of photovoltaic cells is affected by outside factors such as light, tempera- ture,with nonlinear characteristics. In order to improve the efficiency of photovoltaic power generation sys- teros the output power must be tracking. Firstly,it analyzed the equivalent circuit and output characteris- tics of photovoltaic cells, and the simulation model of photovoltaic system was established based on Mat- lab/Simulink; secondly,it expounded the Maximum Power Point Tracking （MPPT） control principle, and the implementation algorithm of voltage type disturbance observation method was researched, through comparison the size of the successive power through the MPPT controller to determine the voltage disturb- ance direction of photovoltaic cells, the Maximum Power Point of photovoltaic cells eventually reached. Fi- nally,the simulation results show that the changes in illumination,MPPT controller can adjust in time and make the photovoltaic cells work in the maximum power point through the simulation tests,therefore the results testify the correctness of photovoltaic system models and reliability of the MPPT control strategy.