Research On 10kW On-board Charger And Its Software Strategy

With the continuous development of industrial production and the continuous improvement of people's living standards,more and more families choose automobiles as their necessities.However,because of the use of fossil energy,traditional automobiles emit tail gases which are mainly composed of sulfur dioxide,nitrogen oxides,carbon monoxide,lead and solid suspended particles,which cause serious pollution to the environment and seriously affect the sustainable development of society.Under this background,compared with fuel vehicles,electric vehicles have the advantages of low noise and zero emission,which can alleviate the problems of life,environment and resources,and become the main development object of new energy vehicles.For the battery charging system of new energy vehicles,a high-power on-board charger is proposed in this paper.The on-board charger consists of front and rear two stages.The front-stage topology of the circuit is three-phase six-switch APFC structure.The rear-stage uses full-bridge LLC resonant converter.The charger can realize the soft switching process of power switch in the full load range,and has high power factor and conversion efficiency.In this paper,the working principles and characteristics of various topological circuits in front and back stages of chargers are studied respectively,and their respective disadvantages are explained.Then the advantages of the final topological circuit for wide range output and high efficiency are introduced.The advantages and disadvantages of on-board charging modes of electric vehicles and electric power are introduced.The main parameters of the front and rear circuit and the related control circuit are designed respectively in the charging process of the car.Finally,the embedded software strategy of vehicle charger is studied,such as state machine,fault detection,CAN communication and control strategy.The on-board charger designed in this paper is a high-power vehicle charger with input voltage range of AC187V~253V,output voltage range of DC280V~420V and maximum output power of 10 kW.The correctness of the theory is verified by the simulation and experimental waveforms of the front and back stages.