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This pdf of a thesis covers the design. https://core.ac.uk/download/pdf/20328622.pdf https://core.ac.uk/download/pdf/20328622.pdf Here and elsewhere found two
by Gibbon1 6y ago
This pdf of a thesis covers the design.
https://core.ac.uk/download/pdf/20328622.pdf https://core.ac.uk/download/pdf/20328622.pdf
Here and elsewhere found two issues.
A problem is efficiently driving the rotary transformer due to losses in the drive circuit because air gapped transformers have a lot of leakage inductance. I take that to mean they throw a lot of reactive power back at the drive electronics.
Hidden problem they are trying to solve is these motors are typically/often oil cooled. Oil and slip rings don't play well together.
- adrian_b 6y agoThanks for the link, it is interesting. However the conclusion about the low efficiency of the electronic converter for the rotary transformer is no longer valid. With modern switches of silicon carbide or gallium nitride and with resonant soft switching techniques, the converter should operate at much higher frequencies and at much lower losses. This is what has probably enabled today the manufacturing of a high-efficiency synchronous motor with a rotary transformer by Mahle.
- Gibbon1 5y agoWe agree that issues with the inverter efficiency were fixable with modern designs and components. I'm on this train of thought that the service life of electric power trains is 2 to 5 times that of gasoline ones. There is a potential to design cars that last 30-50 years. Which potentially reduces the environmental impact of vehicles. I've noticed though that people in the automotive industry look at you like an moron when you suggest that the service life of cars may double or triple. I think it's so ingrained they can't think around it.