Design And Emc Research Of Phase-shift Full Bridge DC-DC Converter For Electric Vehicle

DC-DC converter is a kind of power electronic equipment in electric vehicle.It produces electromagnetic interference(EMI)due to the high-speed switching of power switching devices,which may affect the normal operation of sensitive electronic equipment and even DC-DC converter itself.Based on the design of phase-shift full-bridge DC-DC converter,the electromagnetic compatibility(EMC)problems of DC-DC converter are studied through simulation and experiment.In this paper,a simulation modeling method considering cable distribution parameters is proposed,which can improve the accuracy of simulation results of conducted EMI in DC-DC converters.Based on the transmission line model of distributed RLCG components,the high-frequency equivalent model of the cable in test is established according to the cable arrangement in the EMC test standards.Then,in the Or CAD/Pspice simulation software,the simulation models of the phase-shift full-bridge DC-DC converter,test cable and linear impedance stability network(LISN)are combined to build a complete simulation model of conducted EMI testing system.The Spice model of the actual devices are used in the phase-shifting control chip and switching devices,so the simulation results are closer to the actual test results.The experimental results show that the simulation modeling considering cable distribution parameters can predict the amplitude of conducted EMI in the whole test frequency range(150 k Hz to 30 MHz).The radiated EMC test platform was built in a semi-anechoic chamber,and the EMI and EMS of the prototype were tested respectively.In view of the unqualified frequency band in the radiation electromagnetic interference test,the measures of filtering and shielding are adopted to suppress the interference voltage,so that the test results of the radiated interference voltage conform to the standard GB/T 18655-2010.In the electromagnetic sensitivity(EMS)test,the equivalence relationship between the radiation irradiation method and the bulk current injection method is analyzed,and the EMS test of the prototype is carried out by the bulk current injection method,which reduces the cost and improves the repeatability of the test at the same time.The EMS test results of the prototype meet the standard GB/T 33014.4-2016.