To address North American climate change problems, passenger rail offers one solution. However, it typically uses diesel motive power, which can cause health problems. Overhead and/or third rail infrastructure costs often preclude electrification. We examined hydrogen fuel cell/battery hybrid (Hydrail) railway propulsion systems using dynamic simulations as opposed to existing simulations in the literature which rely on static efficiency values. A British Rail Class 156 diesel multiple unit round trip is simulated using a series-hybrid architecture powertrain. Incremental battery masses were used to assess impact on fuel cell size, efficiency, maximum power, and overall hydrogen consumption. Battery mass is employed as a proxy for power and energy capability of the battery. Results suggest that passenger Hydrail systems work well, with hydrogen fuel cells handling most load dynamics. Hybridization with batteries works best and reduces fuel cell stack size and hydrogen consumption, with overall 64% stack efficiency.
Switcher locomotives operate in railway yards where they shunt railcars and assemble trains. Shunting railcars requires frequent aggressive acceleration and deceleration events in order for the locomotive to push or pull railcars onto specific tracks. As a result, switcher locomotives rarely sustain tractive power for any significant period of time. Given that all switchers in North America rely on diesel-electric propulsion; the result is rapid and frequent transitions in engine power leading to a very low engine efficiency and high levels of emissions. Any attempt to quantify or remedy these issues will face a lack of a representative profile or test cycle. A locomotive duty cycle is a breakdown of time spent at each power level of the locomotive’s engine. A major drawback of current duty cycles is that they only account for steady power. Such cycles are not representative of real switcher locomotive operation. This paper presents a real-world transient duty cycle for switcher locomotives that accounts for the rapid power transitions and is argued to be more statistically representative of actual operations. The methodology adopted relies on real-time data collection, microtrip based trip segmentation, and a finite mixture model-based clustering algorithm. Measurements were collected on a EMD 16-645 GP9 locomotive. The duty cycle developed herein is representative of switching operations in Southern Railway of British Columbia’s New Westminster Yard as an example of the methodology which can be repeated in other cases as well.
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