Research On Solar Charge Interface And Energy Management Of Charging And Discharging Machine

Energy issue has become a most important issue of the world. With the development of powerelectronics, a newly energy-saving and environment-friendly transportation tool—Electric Vehicleshas developed rapidly, which doesn’t depend on fossil fuel. However, charging stations are necessaryfor electro-mobiles, so governments of all countries have put great manpower and material resourcesto the construction of them. Thus relevant technology of charging stations has become a hot spot forresearchers currently. As the most kernel device of a Electric Vehicles charging station,charging-discharging machine determines the security, stability and high efficiency of the wholesystem.In this paper, the development of power technology for independent photovoltaic system isintroduced simply. Devices for solar power generation used in charging-discharging machines are alsopresented and analyzed simply. For the application background of merging the output intohigh-voltage DC bus, the highly efficient parallel interleaving Boost circuit topology with softswitching is chosen after comparing with several other kinds of common topologies. On this basis,several kinds of maximum power point tracking(MPPT) control methods which are mostfrequently-used are introduced, modeled on algorithms and simulated. Aimed at the merits anddemerits of respective methods, an optimized MPPT control algorithm based on converter topology isproposed, analyzed in detail and compared with former several kinds of control methods, superiorityof which is highlighted. Meanwhile, working principles and modes of primary circuit topology areparticularly analyzed in this paper. Parameters of primary circuit are calculated and power devices areselected. Finally, power flowing of the whole charging-discharging machine system is analyzed.Working characteristics and power flowing characteristics of converters on respective working modesare confirmed. Then basic system power management and control strategy are proposed.On the basis of theoretical deduction, simulation is used to test and verify it, examinationplatform is designed and built. Then examinations under two working conditions of hard-switchingand soft-switching are taken. Through simulation and examination results, the validity of theoreticaldeduction is verified.