Research On Household Photovoltaic Inverter Power System

Energy is the basic driving force for the development of human society and economic growth,however,while human beings are benefiting from the scientific and technological progress,economic development and other interests which are brought by the energy,they are also facing a series of problems,such as energy shortage,environmental pollution and so on.Therefore,in order to achieve the sustainable development of human society,we must rely on scientific and technological progress as well as the effective development and utilization of new energy. Solar energy is inexhaustible and it has a Unlimited storage, is clean to explore,meanwhile,it is universal in nature .Its exploitation is the effective way to solve the energy shortage, environmental pollution and greenhouse,solar energy is the ideal alternative energy. Considering the remoteness of some areas, power grid can not be covered,which is hard to meet requirement ,however,these areas are usually very rich in solar energy resources, so it is of vital realistic significance to development and design of a good performance photovoltaic inverter systems.Firstly,the composition of photovoltaic inverter system is introduced and the characteristics of solar cells are analyzed. Because of the costliness and the specific electrical characteristics, the maximum power point tracking (MPPT)is taken into consideration to maximize the use of solar energy and improve the efficiency of the system to save cost of power generation. And then simulation about the solar cells and MPPT are analyzed .Being the weakest part of the system,the battery is used for energy storage, which directly effects the life of the system. Four-stage charging method is used here ,according to the characteristics of PV power systems,the charging circuit and the release point circuits are designed respectively to realise optimal battery charging and the best discharging.Thirdly, system main circuit consisits of the DC-DC step-up and DC-AC inverter part, parameters are designed here, where boost links use BOOST circuit, MPPT is achieved based on it, while inverter part use full-bridge to complete.In order to provide power for the control system and other links, the auxiliary power system is also designed, whose input is the input voltage of photovoltaic array. Because high-frequency transformer and switch are used in the system design ,the problem of electromagnetic interference should be considered, the system electromagnetic interference is analyzed and some restraints are proposed .System control section use TMS320F2407A DSP to complete the control of the hardware and software design.Based on the studies above, a 700W photovoltaic inverter system is designed and its performance test is finished .Experiment results show that the system performs well and all the indicators meet the design requirements.