Conceptual design of an aviation propulsion system using hydrogen fuel cell and superconducting motor

Author(s):  
Gi-Dong Nam ◽  
Le Dinh Vuong ◽  
Hae-Jin Sung ◽  
Seok Ju Lee ◽  
Minwon Park
Electronics ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 1259
Author(s):  
In-Ho Cho ◽  
Byoung-Hee Lee ◽  
Seong-Yun Park ◽  
Joon-Hyoung Ryu ◽  
Jong-Hoon Kim

Due to the problem of global warming caused by greenhouse gas emissions, internal combustion engines in a lot of transportation systems are being electrified. For the railroad propulsion system, it is essential to apply a high-voltage/large-capacity energy source in order to ensure that the system operates properly. Thus, fuel-cell and rechargeable battery systems are being considered nowadays. The battery system can receive and store all regenerative energy to improve energy efficiency. In addition, since the battery pack of a propulsion system utilizing a hydrogen fuel-cell requires continuous charging/discharging, regardless of the railroad vehicle’s driving profile, the battery pack is designed to ensure its stable use and to minimize maintenance costs. Consideration should be given to the characteristics of railroad vehicles. In this research, a hydrogen fuel-cell hybrid railroad vehicle propulsion system specification, which has been studied recently, was applied to study the considerations in the design of high-voltage/large-capacity battery packs for railroad vehicles. In particular, the passive and active cell-balancing circuit and an algorithm for the stable management of battery packs for hybrid railroad vehicles in which a continuous charging/discharging operation is repeated are proposed and verified through experiments.


2021 ◽  
Vol 489 ◽  
pp. 229450
Author(s):  
Sahar Foorginezhad ◽  
Masoud Mohseni-Dargah ◽  
Zahra Falahati ◽  
Rouzbeh Abbassi ◽  
Amir Razmjou ◽  
...  

Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4384
Author(s):  
Hanhee Kim ◽  
Niklas Hartmann ◽  
Maxime Zeller ◽  
Renato Luise ◽  
Tamer Soylu

This paper shows the results of an in-depth techno-economic analysis of the public transport sector in a small to midsize city and its surrounding area. Public battery-electric and hydrogen fuel cell buses are comparatively evaluated by means of a total cost of ownership (TCO) model building on historical data and a projection of market prices. Additionally, a structural analysis of the public transport system of a specific city is performed, assessing best fitting bus lines for the use of electric or hydrogen busses, which is supported by a brief acceptance evaluation of the local citizens. The TCO results for electric buses show a strong cost decrease until the year 2030, reaching 23.5% lower TCOs compared to the conventional diesel bus. The optimal electric bus charging system will be the opportunity (pantograph) charging infrastructure. However, the opportunity charging method is applicable under the assumption that several buses share the same station and there is a “hotspot” where as many as possible bus lines converge. In the case of electric buses for the year 2020, the parameter which influenced the most on the TCO was the battery cost, opposite to the year 2030 in where the bus body cost and fuel cost parameters are the ones that dominate the TCO, due to the learning rate of the batteries. For H2 buses, finding a hotspot is not crucial because they have a similar range to the diesel ones as well as a similar refueling time. H2 buses until 2030 still have 15.4% higher TCO than the diesel bus system. Considering the benefits of a hypothetical scaling-up effect of hydrogen infrastructures in the region, the hydrogen cost could drop to 5 €/kg. In this case, the overall TCO of the hydrogen solution would drop to a slightly lower TCO than the diesel solution in 2030. Therefore, hydrogen buses can be competitive in small to midsize cities, even with limited routes. For hydrogen buses, the bus body and fuel cost make up a large part of the TCO. Reducing the fuel cost will be an important aspect to reduce the total TCO of the hydrogen bus.


2021 ◽  
Vol 7 ◽  
pp. 2635-2646
Author(s):  
Nabeel Ahsan ◽  
Ans Al Rashid ◽  
Asad A. Zaidi ◽  
Ramsha Imran ◽  
Sikandar Abdul Qadir

2020 ◽  
Vol 89 ◽  
pp. 102897 ◽  
Author(s):  
Scott Kelley ◽  
Aimee Krafft ◽  
Michael Kuby ◽  
Oscar Lopez ◽  
Rhian Stotts ◽  
...  

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