- #1
pchoopanya
- 25
- 0
Good afternoon from England!
I am sure this is not a homework, rather an engineering project.
I am interested in an alternative way of electrically propelling a transit bus using a combination of solid oxide fuel cell and battery, focussing on its powertrain.
Two powertrain configurations arise;
1. A battery-dominant powertrain =>>> a bigger battery is the prime mover, having a smaller solid oxide fuel cell which constantly and continuously feeds the generated electricity to the battery. SOFC is also used to feed auxiliary devices. A re-gen brake is also used. Here, the SOFC acts as a range extender, extending the driving range. An example is the ABSOLUTE project proposed by Imperial College researchers in London.
2. A fuel cell-dominant powertrain =>>> having an SOFC as a prime mover and it also powers auxiliary electrical devices. Transient power requirement is provided by a smaller battery. Again, a re-gen brake is also to be used. The example is a Mercedes-Citaro fuel cell bus - however, it uses a PEM fuel cell. Such the buses are operating for a CUTE project.
I wonder if anybody could comment on the pros and cons of these two arrangement?
Which one is more practical and better in terms of a transit bus application?
The only drawback I can see so far with the first layout is the weight and size of the battery since it needs to be big enough to provide sufficient energy.
The problem with the second layout is that I am not sure if we can rely on a long start-up time of SOFC. It may take several minutes? Will this make the layout impractical even though the only fuel cell vehicle does exist?
Another problem is the energy required to heat up the fuel cell stack. The energy could be obtained from the stored energy from a battery when we start the bus, but will it turn out to be a waste of having a battery since all stored energy might be used up. And there won't be enough energy from a battery to compliment the prime mover (SOFC) when required during a trip. Does anyone know how the fuel cell Citaro bus actually work in this arrangement?
Please share your opinion, every single opinion or knowledge from you guys is so valuable to me. Thank you so much.
PS - Sorry if I make you confused with my poor English.
PS2 - Do we use "a" or "an" in front of the acronyms, example SOFC, PEMFC
PS3 - I have also attached my current idea, using a SOFC as a range extender. It feeds the battery as well as power on-board electrical devices
I am sure this is not a homework, rather an engineering project.
I am interested in an alternative way of electrically propelling a transit bus using a combination of solid oxide fuel cell and battery, focussing on its powertrain.
Two powertrain configurations arise;
1. A battery-dominant powertrain =>>> a bigger battery is the prime mover, having a smaller solid oxide fuel cell which constantly and continuously feeds the generated electricity to the battery. SOFC is also used to feed auxiliary devices. A re-gen brake is also used. Here, the SOFC acts as a range extender, extending the driving range. An example is the ABSOLUTE project proposed by Imperial College researchers in London.
2. A fuel cell-dominant powertrain =>>> having an SOFC as a prime mover and it also powers auxiliary electrical devices. Transient power requirement is provided by a smaller battery. Again, a re-gen brake is also to be used. The example is a Mercedes-Citaro fuel cell bus - however, it uses a PEM fuel cell. Such the buses are operating for a CUTE project.
I wonder if anybody could comment on the pros and cons of these two arrangement?
Which one is more practical and better in terms of a transit bus application?
The only drawback I can see so far with the first layout is the weight and size of the battery since it needs to be big enough to provide sufficient energy.
The problem with the second layout is that I am not sure if we can rely on a long start-up time of SOFC. It may take several minutes? Will this make the layout impractical even though the only fuel cell vehicle does exist?
Another problem is the energy required to heat up the fuel cell stack. The energy could be obtained from the stored energy from a battery when we start the bus, but will it turn out to be a waste of having a battery since all stored energy might be used up. And there won't be enough energy from a battery to compliment the prime mover (SOFC) when required during a trip. Does anyone know how the fuel cell Citaro bus actually work in this arrangement?
Please share your opinion, every single opinion or knowledge from you guys is so valuable to me. Thank you so much.
PS - Sorry if I make you confused with my poor English.
PS2 - Do we use "a" or "an" in front of the acronyms, example SOFC, PEMFC
PS3 - I have also attached my current idea, using a SOFC as a range extender. It feeds the battery as well as power on-board electrical devices