Analysis of energy storage devices in hybrid railway vehicles

This paper presents an analysis of the energy storage requirements for hybrid railway vehicles. Autonomous hybrid railway vehicles combine two power sources. The conventional diesel prime- mover is supplemented with power derived from an on-board energy storage device. The device is discharged during high power demand, and may be recharged through regenerative braking. The energy savings that are achievable through the adoption of such technology are also dependent on the duty cycle. It is shown that for a given vehicle there is a inter-station distance beyond which the benefits become marginal. The performance of the energy storage device fundamentally affects the whole system performance and careful consideration is required in device selection. The constrained nature of the railway system also presents opportunities for optimization of architectures and control strategies. These methods are also discussed in this paper. Finally, a review of practical implementation considerations is presented.