Evaluation of design method for engine output and battery capacity for lithium ion-battery hybrid diesel railway vehicles

Diesel engine lithium-ion battery hybrid vehicles are gaining attention because the energy consumption during their operation and exhaust emission can be reduced considerably. However, designing a reasonably accurate method for the engine power and battery energy has not yet been proposed, though the above mentioned type of traction system can help in realizing an environment-friendly railway vehicle. In this paper, a design method for the battery capacity (energy) and engine output is proposed in the case of a control strategy in which the sum of the kinetic energy of the vehicle and the battery energy is maintained constant. The proposed method is verified by the velocity/state of charge of the battery charts obtained in the experimental tests. The proposed design method can be used to develop the environment-friendly railway traction systems for non electrified lines.