Simulation on Conducted Disturbance in Driving System of Novel Fuel Cell Bus

Fuel cell vehicles have shown their advantages in clean run and high efficiency compared with the traditional internal combustion engine vehicles,but they would cause more serious EMC(Electromagnetic Compatibility) problems.So the EMC research about these new kinds of vehicles is being focused on.It is verified that the driving system on the fuel cell vehicle could generate high frequency disturbance for the switching of the IGBTs(Insulated gate bipolar transistors).This is one of the main conducted disturbances in fuel cell vehicle.High frequency circuit model of driving system is a very effective tool to research the transient response,which could help to reduce the related disturbance effect.This kind of model should include the time-variable parameters caused by the switching of the IGBTs and the frequency-variable parameters caused by the skin effect of the cables and the AC motor.In this paper,the fuel cell model and IGBTs model are set up based on the other's work.The frequency-variable parameters of the cables and the AC motor are measured on the real fuel cell bus.The vector fitting method is applied to fit the complex frequencyvariable parameters into rational form which could be transmitted into time-domain easily by convolution.Then the time-variable parameters and the frequency-variable parameters could be considered together in time domain.One advantage of this method is that it could avoid calculating a lot of frequency point as necessary in frequency domain method.Another is that it could be extended to consider more complex time-variable parameters of IGBTs.This method can save a lot of calculation time.The transient response is analyzed when one bridge of the inverter is switching.Simulation results fit well with the experimental data and this method is proved to be effective.