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Minghao met with Prof. Michael Fowler in the Chemical Engineering department on the morning of Sept 20, 2017. Prof. Fowler was shown our compression-based proof-of-concept module assembly and asked for general input regarding pack design and verification. He also provided key contacts within the Chemical Engineering department for potential access to lab equipment and software.

Summary

Prof. Fowler sent the following email on Oct 9 summarizing his notes from our meeting:

Safety is critical.

1. Test each module first and then full pack testing.
2. The BMS should have extensive testing for all likely failure modes (a HIL – hardware in the loop testing should be OK)
3. The Pack Container must of able to withstand a Crash and/or Debris penetration. Solid state modeling and simulation is recommended.
4. Pack Container must fully isolate the driver from the pack.
5. Stefanie Bruinsma stefanie.bruinsma@uwaterloo.ca in GAIA may have a Pack Cycler you can test you pack on.
6. Compression electrical connections are not acceptable.  Everything must be welded or bolted.
7. Thermal modelling in COMSOL is highly recommended. Dr. Nasser Lashgarian Azadnlashgarianazad@uwaterloo.ca in Systems has done Air Cooling modelling for such packs.
8. Full Kapon Sheets are recommended between all modules and lining of your pack container.

Michael Fowler

E6 - 1110

519-888-4567 Ext 33415

mfowler@uwaterloo.ca

Pack Design

Compression vs. Spot Welding

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Prof. Fowler said that the gaps we have between every two cell rows for airflow are necessary unnecessary and that the standard inter-cell gap provided by adjacent cell holders would be fine provided that we have active cooling. He initially proposed a stronger cooling solution such as a thermoelectric cooler but after Minghao explained that our motors have a combined draw of 20 hp, he became less concerned.

Regardless of out our design, Prof. Fowler emphasized that it was critical for us to perform airflow and heat transfer simulations in COMSOL (or ANSYS). He said that all chemical engineering students have access to COMSOL through servers but that he could also help us obtain access as a team. COMSOL is supposed to have Li-ion models built-in.

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