Research And Implementation Of Solar Charging Controller Based On

Photovoltaic technology and industry is not only an important supplement of current energy consumption,but also has the potential to become the main source of energy in the future. In order to maximize the use of solar energy, this thesis focuses on the analysis、design and making of the maximum power tracking solar charging controller.The technology of MPPT has been applied on three main aspects:(1) It was used to supply power for load with the maximum power;(2) It was used for charging the battery with the maximum power;(3) It was applied on the photovoltaic grid-connected system for feeding energy with the maximum current.Because the output characteristics of PV systems are susceptible to the influence of environmental factors such as light intensity, temperatur, and it’s a common that the photoelectric conversion efficiency of Photovoltaic power generation system is very low at the same time. So this thesis focuses on the using of aspect 2 and has designed a maximum power tracking solar charging controller.The work is listed as follows:Firstly, the PV system has been introduced, including the compositions,classifications and applications. The equivalent circuit has also been researched based on the principle of photovoltaic array, and the mathematical model was established under the equivalent circuit, and then the output characteristics of photovoltaic array has been analyzed;Secondly, the definition and principle of MPPT has been introduced. Choose duty cycle perturb method to achieve the maximum power point tracking for the controller;Thirdly, a four-stage photovoltaic charging method has been improved based on PV output characteristics, the hardware and software of PV charging system have been designed on request of charging process after analyzing battery charging characteristics and charging methods. The hardware used the STM32F103 series as the microcontroller, focusing on the analysis of the principle of the Buck circuit and flyback power based on UC3843 and calculated the relevant parameters. I have designed the tracking algorithm of maximum power point, the control algorithm of battery charging or discharging and on or off algorithm of UC3843 based on researching the charging characteristics of the storage battery.It could charge the 12 V storage battery with intelligent segment mode and control the discharging afterpractice. The design of low power solar charger accorded with practical application,laid emphasis on utilit and cost control could be productization after subsequent improvement. I have built the PV charging experiment platform after making the maximum power tracking solar charging controller. By testing and analyzing the data,it shows that the duty cycle perturb method can improve tracking efficiency.