Design of Parallel Hybrid Electric Bus with Emphasis on Regeneration Braking

The paper chooses BJ6112C6MHB as a prototype vehicle and converts it to a parallel hybrid electric vehicle (parallel HEV). In the event that the engine and the transmission of the vehicle have been decided in the former work, the type of the motor and energy storage is analyzed and decided. The study of the motor parameter design in the mode of regenerative braking is stressed and the paper considers the parameter based on respective requirements of the other three modes: hybrid driving mode, pure electric driving mode and engine crank mode. The optimal parameters and performance curve of the motor are achieved after comprehensively analyzed the results from each mode requirement. It is found in the comparison and analysis that the parameter design in the mode of regenerative braking plays the key roll. The parameter of energy storage is determined correspondingly. According to the selected type and parameters, the comparative simulation between the prototype vehicle and the parallel HEV is carried out under the Chinese typical driving cycle of city buses, using the simulator ADVISOR. The influences of parameters to the power performance and fuel economy are also studied. After comprehensively comparing the simulation results, the ultimate powertrain system configuration of the parallel HEV is determined and the power performance and fuel economy of the vehicle is improved distinctively.