Abstract
Research and/or Engineering Questions/Objective
Double-decker buses are mainly buses operating in Hong Kong, but high energy consumption and high emissions are serious problems for conventional fuel bus. Facing with the problems above, Tsinghua University and the Hong Kong productivity council developed the electric double-decker bus technical route together.
Methodology
In this study, an electric double-decker bus powertrain configuration with two power sources is presented, based on the buses operating characteristic in Hong Kong, key electric vehicles’ technologies in China including the batteries technologies, traction motor technologies and charging infrastructure technologies. In this scheme, the independent air–conditioner and auxiliary are powered by the gas auxiliary power unit (APU) on-board, and the bus is powered by Li2TiO3 battery packs. Moreover, the powertrain parameters are matched based on the model constructed by Matlab/Simulink, and the energy consumption and dynamic performance in typical city driving cycles are analyzed.
Results
The average electrical consumption is 176kWh/100km in typical driving cycles. The minimum all electric range is 28.4km using the matched battery packs, which can meet the operation requirement in Hong Kong ordinary bus line. Limitations of this study The economy of presented range extended electric powertrain configuration when it is applied on double-decker buses is not considered.
What does the paper offer that is new in the field including in comparison to other work by the authors?
The electric powertrain of double-decker buses with separate APU powering air conditioner to solve the problems of AER decreased sharply by AC energy consumption is innovative and not found in other research.
Conclusions
The results show that, based on the designed powertrain using quickly charging mode, the APU can reduce the influence that the air conditioner can make all electric range significantly decrease. The design proposal has the potential of large-scale promotion in Hong Kong due to its economy and feasibility.
Key Words : Double-decker buses; powertrain parameters matching; auxiliary power unit on-board; independent air –conditioner; energy consumption