Research On Design And Control Algorithm Of MPPT Photovoltaic Controller

With the depletion of fossil energy and the growing environmental pollution problems caused by the use of renewable energy,renewable clean energy has attracted global attention.As one of the renewable energy sources,solar energy has attracted many people’s attention because of its many advantages such as cleanliness and abundant reserves.Photovoltaic power generation is one of the main forms of utilizing solar energy resources,but the output characteristic curve of photovoltaic cells will change with the changes of light intensity,ambient temperature and other factors,thus affecting the photoelectric conversion rate of photovoltaic cells.Maximum Power Point Tracking(MPPT)technology is a key technology to improve the output power of photovoltaic cells,and plays a vital role in the increase of power generation of the entire photovoltaic power generation system.The paper aims to maximize the output power of photovoltaic cells and carried out research on the MPPT photovoltaic controller and its control algorithm.Firstly,by analyzing the working principle of photovoltaic cells,a mathematical model of photovoltaic cell equivalent circuit engineering was established,and the relationship between the output characteristics of photovoltaic cells and the light intensity and temperature was obtained through the simulation model of photovoltaic cells.Secondly,the advantages and disadvantages of the conventional MPPT algorithm are analyzed,and the chattering problem of sliding mode control is improved and optimized.The optimized algorithm is compared with the traditional algorithm through the simulation platform of MATLAB/Simulink,which proves that the optimized algorithm has good control performance.Then,the hardware circuit and software program of MPPT photovoltaic controller are designed,including the main circuit DC/DC circuit,passive lossless soft switch circuit,control circuit,sampling circuit and other hardware circuit selection and parameter calculation.The design of software includes the design of main program and ADC interrupt subroutine and PWM interrupt subroutine.Finally,an experimental platform of photovoltaic control system was set up to verify the performance of the optimized MPPT control algorithm,and to verify the effect of MPPT controller on improving the output power of photovoltaic cells.The experimental results show that the optimized sliding mode control method has good control effect and the designed MPPT controller can effectively improve the output of photovoltaic cells.