Pwm Inverter For Solar Energy Dc-dc Circuit And Maximum Power Point Tracking Technology

Shortage of energy sources and pollution of environment in the world are becoming more and more serious. The delicate problems compel scientists to search for new energy sources that can substitute conventional ones. Therefore, developing and using renewable and clean energy sources such as solar energy which is economical and nonpolluting are taken into account seriously. All sorts of technologies of utilizing solar energy including photovoltaic generation have made great strides. In this paper, the DC-DC convertor is researched as a part of photovoltaic inverter which can work in stand-alone or grid-connected mode.First, the background and significance of this thesis is simply introduced. At the same time, the main research content is also depicted, too.Next, the topology and operating principle of push-pull forward inverter based on high-frequency link technology are analyzed. Then some aspects are elaborated detailedly such as design of the high-frequency transformer, selection of the devices of main circuits and computation of the filter parameters.Subsequently, the control idea is expounded in detail. Then the main DSP control circuit, testing circuits, protective circuits, driving circuits and keyboard display circuit are interpreted respectively. The idea of control software is also given in detail.And then, based on analysis about photovoltaic cells characteristics a modified incremental conductance Maximum Power Point Tracking algorithm which only need measure one current variable is presented, pointing to the mathematical model of photovoltaic cells and transfer characteristic of push-pull forward inverter. The results of simulation indicate the new MPPT algorithm is precise.Final, an experimental prototype is produced successfully, and the experimental waveforms are obtained by Tektronix oscilloscope. The results prove the correction and applicability of the schemes.