The Simulation And Design Research On Household Photovoltaic Inverter System

Energy is the basic factor for the modern society progress and economic development. And it is also the material guarantee for our daily life that can ’t be lack.,However,while human beings are benefiting from so many material benefits brought by energy, we have to face so many problems, for example, energy shortage and energy security crisis which are caused by excessice ene rgy consumption and environmental pollution. Human beings are influenced by all these problems badly. So we must speed up new energy development and technical improvements, and then deal with the problems about social sustain ble development with the shortage of resources and the serious environmental problems. Solar energy is a gift with enormous reserves, and it’s renewalbe resources. In the process of using, it’s clean,huge reserves and easy to get..Us ing solar is a good way to solve the problem about environment polution, gre en house and resource shortage. Furthmore, the method by electricity transmis sion grid is limited by district, there are some coteau and remote area have n o access to electricity. So we study about photovoltaic inverter systems, and t ry to make out of a system with high performance, and it would play a posit ive role in promoting human’s life.For the photovoltaic inverter system, we introduce about the composition, and then focused on one of the most important parts of the system which is solar cells. For the problem about price and output characteristics, we sutdy on the maximum power point tracking (MPPT), and try to improve the work efficiency of solar energy. So we do the Simulation studies on these two aspects by software. We used the theory to guide model, and also used the model verified the theory. But on the other hand, the battery is fragile, and it is One of the most vulnerable parts, so the performance about solar cells is very important to the whole system. Because of the characteristic on temperature and illumination, we add the trickle charge and float charge into the charging method, which called Four-stage charging method. The method can optimize the charging process. We used BOOST circuit to be the DC-DC step-up. And it is comprised of inductance,diode and so on. MPPT is achieved based on the DC-DC step-up. The circuit of DC-AC inverter part use full-bridge to work. And it is comprised of IGBT switch tube, the association of diode and so on. To ensure that the system can get enough power, we used Topswitch to make the auxiliary power system. And it is input is the output voltage of cells. During the transmission of EMI signal, the system would cause electromagnetic interference. So we analyzed the reasons of electromagnetic interference, and then offered some solutions. In the system, we used DSP(TMS320F2407A) to be the main control chip of circuit.Based on the studies, we finally designed a 700W photovoltaic inverter system. And the results show that the system is very good in performance. Most of the design expectations and indexes are consistent.