Research And Development Of Integrated Vehicle Power Supply System With Inverter Function

At present,in order to rise the running distance of new energy vehicles,the electric capacity of a single vehicle continues to rise,and the charging time rises accordingly.The power of on-board charger(OBC)is gradually rised to shorten the charging time.In the limited vehicle placement area,more space shall be reserved to place power batteries,and the volume of other non driving functional devices shall be as small as possible.Therefore,the design and development of vehicle parts system is gradually integrated.The integration of OBC and other parts of the vehicle has become the first choice of main engine factory.Based on the research status of OBC and low voltage DC/DC converter(LDC)at home and abroad,this study proposes an amalgamated on-board power supply system with power inverter function.Compared with the current mainstream research,the innovation is that its topology has bidirectional charging and discharging capabilities,and integrates OBC and LDC magnetically.Its power devices are made of Si C materials.Power factor correction(PFC)circuit achieves 6.6k W and 11 k W charging power by adjusting the circuit structure.The 6.6k W single-phase charge is a staggered parallel totem pole PFC structure,the 11 k W three-phase charge is a three-phase six switch PFC structure,and the discharge is a single-phase full bridge inverter structure;The latter stage of OBC adopts symmetrical CLLC resonant converter,which supports forward and reverse operation.CLLC resonant converter and LDC form a three port converter structure.The system is mainly divided into bidirectional OBC mode,driving mode and joint operating condition.The operating principles of the three Operating condition are explained.According to the system power,input and output voltage and current and other design indicators,the PFC circuit parameters,integrated transformer parameters,resonance parameters and LDC filter system parameters are designed.Firstly,the control strategies of three operation modes of the front PFC circuit and the rear three port converter are studied.The control methods under different operating condition of each module are proposed,and test analysis is conducted by MATLAB/Simulink.Then,the system model is built to test and prove the basic charging and discharging performance of the system.Starting from the vehicle end,the performance of the on-board power system is further proved.The test results meet the scheme purpose and prove the correctness of the system control methods.