The Design And Achievement Of DC/DC Converter In Formation System Of High Capacity Lithium-ion Battery

As the power core of the Aeronautics and Astronautics, intelligent phone, electricpower automobile, lithium-ion battery plays a crucial role, toward to the direction ofsmall volume and large capacity for the need of long time of endurance. The fact thatformation equipment of lithium-ion battery is generally less than3A, while up than10Ain serious shortage at present, which restricts and renders its development. The batteryformation equipment is constituted by several groups DC/DC converters, so theresearch and development of high capacity formation equipment is essentially that oflow-voltage high-current DC/DC converter.Considering the above analysis, this thesis to the low-voltage high current DC/DCconverter and applies in the formation equipment as the reaches object. Through theanalysis of the topology of DC/DC converter this thesis tries to design one low voltageand high current DC/DC buck converter which is applicable for the formationequipment to meet the demand for high-capacity lithium-ion battery. Implementationwork of low-voltage high-current DC/DC buck converter module is listed as follows:1. The thesis analyze the DC/DC converter topology, and then in order to adapt tolow voltage and high current, the half-bridge-and push-pull topology are usedrespectively as the main topology structure of charging and discharging module, besides,some main circuit structures are software simulated and analyzed. In the premise of allthe work we have mentioned above,2. Calculates the frequency transformer parameter of DC/DC and dropping the coreaccording to the parameter chose proper magnetic core and coil, than process thetransformer. Than reasonable power devices are selected and then are applied into thechopper circuit and the output rectifier filter circuit.3According to the design requirements, TL494is uses as the power control chip tocomplete the control circuit design, and then the concrete design of collecting circuit,feed backing loop and protecting circuit will be carried on one by one. Than the loss ofswitch, transformer and rectifier filtering is calculated4. Through a series of welding and debugging, the hardware experiment platform of DC/DC liter voltage dropping module is completed. At the same time, the work oftest and analysis are done. Than several DC/DC modules are applied in the formationequipment. The conclusion is drawn by the test of experimental platform: its efficiencyis up to76%and73%during the discharging process.Finally the result shows that the DC/DC charging and discharging module canrealize the20A current formation ability stably, and satisfied the need of high capacitybattery formation equipment.