Influence of gear number design on energy consumption for an electric bus

In order to analyze the effect of gear number on the energy consumption of electric bus and the gearbox configurations, a power-train model of an electric bus was build, the AMT gear number was configured to be 4, 3 and 2 respectively. Dynamic programming was applied to find out the optimal gear shifting trajectory for the 3 gearbox configurations under 4 different driving cycles, then the two-parameter gear shifting strategies were extracted from the optimal results, and the minimum energy consumptions for the 3 gearbox configurations were achieved from simulation. The result shows that: compared to 4 speed gearbox, using 3 speed gearbox bring 1% extra energy consumption, while 2 speed gearbox bring about 5% extra energy consumption.