Fast Charging Technology Of Battery Based On A Single Stage AC/DC Resonant Topology

The application range of the battery and the development of the charging technologyof the battery and the research status of the battery charging power supply are analyzed,which is embodied the advantages of high efficiency and high power density of the powersupply. The topic uses a two-stage topology. The former level uses a single-stage AC/DCresonant topology to improve the efficiency of the power. The latter level uses positive andnegative pulse fast charging method as control method, which can better improve thecharging current curve of the battery by adopting the bi-directional DC/DC topology.To improve the power factor and decrease the system losses, two kinds ofsingle-stage AC/DC resonant converter is introduced after one cycle control method isused in boost topology and LLC resonant converter is studied. The difference between thetwo topologies is the number of inductances. The accepted topology integrates aninterleaved boost PFC converter with a half-bridge-type LLC resonant converter into asingle-stage power converter. The converter uses interleaving methods to achieveinput-current shaping with input-voltage and soft-switching function on two active powerswitches to reduce their switching losses in order to increase the circuit effieiency. TheFHA analyses method and the close-loop control method are in accord with the commonhalf-bridge LLC resonant converter.Then six kinds of non-isolated bi-directional DC/DC topologies are introduced, as aresult, the bi-directional Buck/Boost topology is chosen as the latter level topology.Working principle of Buck/Boost converter is analyzed, and mathematical modelling ofthe charge and discharge circuit is introduced. A close-loop controller is designed.Finally, the former level topology and the whole system is experimentalized after theexperiment platform is designed and built. The experimental results show that the formerlevel topology can realize the input current followed by the input voltage, and theinterleaving control method makes the power factor higher. It also can realize softswitching of the switches and decrease the switching loss of the whole system andimprove the efficiency of the system. The bi-directional DC/DC topology used in battery charging system optimizes the design work and has a good experiment effect. In a word,the whole charging topology is feasible.