Research Of Photovoltaic System Using An Adaptive Interval Perturbation MPPT

With the lack of energy and serious environment pollution problem in the modern society, renewable solar energy of clean has caused the attention of the people and therefore, the development of photovoltaic application has a bright future. However, the low efficiency of photovoltaic cells and easily to be affected by the external environment are the important reasons of the development restrict of the photovoltaic power generation applications, which can be solved by the MPPT technology that can make the maximum power of photovoltaic cells output directly in a complex environment. Therefore, the MPPT technology has become a current research hot spot. The main research content is shown as follows:(1) In order to balance both tracking speed and steady-state oscillation, the paper designs an adaptive interval perturbation MPPT through the study of the characteristics of the commonly used MPPT algorithm. First,the short circuit current method for short circuit testing is modified to estimation method of no power loss, then the voltage disturbance is modified to current disturbance which has faster response speed. Finally, it ranges and clamps in the adaptation interval by the calculation of short circuit current estimation method with small current disturbance. The tracking speed up nearly 2 times faster than the traditional methods. The steady-state oscillation decrease significantly.(2) With respect to the loss problems of the traditional SCM and Buck circuit, the system controlled by MSP430 + SM72295 scheme of staggered parallel Buck main power circuit in order to improve the efficiency of the system, that has realized the function of high efficiency DC- DC transform. The maximum efficiency reached 97%.(3) In order to control the uncertainty of light environment and load power, the system charges the battery by EG4318 + UC3842 with the scheme of a three-stage charging management, which realizes the functions of the mains complementary and also increase the life span of the battery.(4) In order to make the secure and stable operation of the equipment, the use of a serial port turn Wi Fi module and android mobile phone, mobile phone remote photovoltaic monitoring function is realized through the cloud data forwarding.