Research On The Solar Photovoltaic Power Generation System For The Families Based On The Technology Of MPPT

Nowadays conventional energy crisis and the environmental pollution have becomeincreasingly prominent. To develop other renewable energy sources, such as solar, hasbecome a consensus among the countries of the world, which also makes the solarphotovoltaic industry develop more rapidly in recent years. It not only can reduce theenvironmental pollution, but also can meet the demand for electricity for the families whichare far away from urban area and without electricity or lack of electricity to develop the solarphotovoltaic power generation. At present, trend of the independent photovoltaic powergeneration system into the families also develops more quickly.The solar photovoltaic power generation system for the families is researched anddesigned in this paper. Firstly, the output characteristics of the solar cells are simulated on thebasis of its working principles. The principle of maximum power point tracking (MPPT) isexplained according to the non-linear relationship of the output characteristics of the solarcells. Some commonly used maximum power point tracking (MPPT) algorithms are simulated,which are combined with DC-DC converter. A novel MPPT algorithm is presented bycomparing the advantages and disadvantages of them. Then properties of the charge anddischarge of the battery, which is used to store energy, are researched. After that the capacityof it is calculated according to the requirements of the load. The former circuit uses the Boostconverter to charge up the battery.Secondly, taking the low voltage level of the battery into account and in order to output220V AC, the structure of “push-pull boost circuit+full-bridge inverter” is used finallythrough the analysis of several topology structures to improve the efficiency of the wholesystem. Design of the whole system includes both hardware and software. Selection of theparameters of each component、design of the high frequency transformer and its control circuit are introduced in the push-pull circuit, where the output PWM drive circuit uses thetotem pole to enhance its drive ability. The inverse circuit also shows the selection methods ofthe power switch and filter. The over-current protection and sampling circuit of the voltageare designed in this part. Simulation results of the transfer function of the filter prove therationality of the design. In this design part of the software, control of the MPPT、generationof the drive signal of SPWM and closed-loop feedback control of PI regulation are realizedbased on DSP.Finally, this paper gives out the debugging results of relevant experimental circuit, whichrealize the function of each part and verify the rationality of the design.