The System Design Of Charger In Electric Vehicle

Over the years, the rapid development of automobile industry has brought the problemssuch as environmental pollution and resource consumption, which is difficult to be solved. ifthis continues, we can imagine the serious consequences. Under the circumstances, thecountry is committed to developing new energy vehicles, and pure electric vehicles is one ofdevelopment direction. Pure electric vehicle has zero emissions and low consumption, whichmeets the demand of the development of modern automobile industry. Electric vehicle energysources for power battery, and in this paper, I choose lithium battery as the power batterywhich has superior performance compared with others; Lithium battery’s energy sourcesinclude off-board charger and on-board charger.With the help of the national ministry of science and technology project863’s researchon electric vehicle charging equipment’s electrical testing technology and standard, this paperaims at the vehicle charging equipment’s common problems such as electrical energy loss andthe failure of charging standard to standardization, in order to improve the on-board chargersystem’s performance, this paper studied and designed a new type of on-board chargersystem.This paper’s control object is lithium battery pack, which is constituted by9510AHlithium batteries, charging method is three-stage charging. This design uses220v alternatingcurrent as the input of the system’s main circuit, after AC-DC、DC-DC voltage transformation,the main circuit’s output DC voltage is adjustable between0and400v. DC-DC converteradopts ZVS soft switch control, which can improve the conversion efficiency of the system.The control circuit, which is based on DSP TMS320F812is current and voltage loops, andthey make the main circuit’s output voltage and current adjustable. Throughout the chargingprocess, the battery management system (BMS) provides real-time sampling of lithiumbattery pack’s charging parameters, and judge the lithium battery pack is in which stage, andthen control the output voltage and current of the system’s main circuit through the CANcommunication, ultimately to ensure the control precision and the security of the system.After the topology structure of the system’s main circuit is determined, this paper firstlycomplete calculation of the parameter value of the system’s main and control circuit’scomponents, then by the means of MATLAB simulation analysis, validate the correctness ofthe main and control circuit, and also determine the components’ selection, then the hardwareand software design which are based on DSP TMS320F2812are completed. Finally, thewhole system of the on-board charger is designed, and it achieves a high performanceindicators in the conversion efficiency and control precision and so on.