Heavy transportation vehicles, such as trains and trams, place particular demands on energy storage devices. Such devices must be very robust and reliable, providing long operational lifetimes and low maintenance requirements. Further, the storage devices must operate efficiently under harsh conditions including:
- Handling peak currents
- High duty cycles
- Frequent deep discharge/charge cycles
Ultracapacitor systems/modules are being used as these demanding energy storage devices. Braking energy recuperation is being utilized to provide assisted propulsion, bridged power, and grid/voltage stabilization in many rail applications today. Additionally, ultracapacitors are being used to provide locomotive engine starting, and assisted starting (battery and ultracapacitor combined system) as a mechanism to eliminate large batteries, or in some cases, to extend the life of the large batteries historically used in locomotive engine starting applications.