Abstract
The meeting for research and development "Next generation City Bus (NCB21)" consists of members from the universities, the manufactures and government offices. This group has developed the driveline, which is the suitable for the series hybrid system used in-motors. As the starting and the stopping occur frequently in the urban transportation, the energy efficiency of the series hybrid system can be increased by the electric energy recovered through regenerative braking. As the result, the series hybrid system is effective in the city traffic conditions. The driveline will enable to adopt the different devices for vehicle power source, and this system can apply easily to the city route hybrid-bus, the fuel cell bus, the trolley bus, the light rail transit (LRT) and the dual-mode trolley bus which uses properly the electric power and other power supplies. The authors evaluated the performance and the characteristics of the motor drive system in this paper. The conclusions are described as follows; (1) The characteristics of the driving motors, riding comfort will be improved the acceleration becomes smooth by no gear-shock and the high torque at low speed. Then, the service to the standing passengers, the aged and the handicapped parsons improves remarkably. (2) If this motor drive system adopts public transportations as the city route hybrid-bus, the trolley bus, LRT and others. The width of the passage on the (rear) axle has enough width and the movement of the wheelchair becomes easily from front to rear. That public transportation contributes to the barrier-free. (3) In case of the series hybrid system used the diesel engine for power source, the displacement volume of the engine has been able to reduce to 1/2-1/3 by planning to make the suitable system. Therefore, it is possible to use much more effectively the unused space of the bus and also to reduce the emission gas (NO_x, PM) and fuel consumption.
