Abstract: A heavily hybrid powertrain configuration using 2 motors and a clutch to couple them was taken as the object of research. This layout cancels the automatic transmission(AMT), avoids the problem that the domestic manufacturers cannot produce the AMT independently. The parameter match was performed with new method to improve the deficiencies of the existed traditional match method,i.e., insufficient consideration of driving cycle conditions and high efficiency area. The proposed new match idea includes 3 main aspects:the vehicle dynamic performance, the power demand of the typical driving cycle in China cities and overlap of the high efficiency areas. The parameters of main components including engine, generator, motor and batttery were match in connection with the control strategy. A hybrid system model was built, and simulations were performed using softwares CRUISE/MATLAB/SIMULINK. The simulation results indicated that the series-parallel bus with the matched paramters can meet the design requirement of performance with fuel economy improvement of 37.6%.

Key words: vehicle engineering, hybrid electric bus, powertrain, parameter matching