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AC Propulsion introducing third-gen Electric Drive System, new motor at EVS26

AC Propulsion, Inc. is introducing the new third generation—Gen 3—Electric Drive System at EVS26. This system features the same 150 kW peak power capability as the Gen 2 system but is updated with revised system architecture and capabilities.

The Gen 3 Power Electronics Unit houses 150 kW inverter and integrated 18 kW battery charger. Click to enlarge.

New features include: reduced size and weight, dual CAN buses and digital system controls. Also new are companion products HVDC-to-12VDC power supply, Battery Pack Control Module and Driver Interface Module. The unique integrated “Reductive” battery charger function is retained which allows up to 18 kW of recharge power for reduced charge time, reduced cost and reduced weight.

Also being introduced is the LCM-150 Liquid-cooled motor. Keeping with the company’s focus on induction motors, this induction machine has the same peak power capability of the AC-150 air-cooled motor (greater than 200 kW), but more than doubles the continuous power rating to 100 kW.

Rotor heat transfer has traditionally been a barrier for higher power applications. The patent-pending design cools the rotor as well as the stator. This greatly expands the application for heavier vehicles.



Ohh 18kW charger is built in!


That's old news; they've had that since the tzero.

The 100 kW motor means the drivetrain can do heavy work like towing.  This takes the system into niches beyond sports cars.


I'm wondering how feasible, and how expensive would be to cool the rotor of induction motor through a hollow shaft. Say the shaft is hollow at both ends but not in the middle, air is forced into one end of shaft, then through holes in shaft into the cavities in the rotor iron.
If it would work at 2,000 rpm, would it work at 12,000 rpm (would air resistance grow dramatically on exits through shaft holes, as rpm goes up)?
It would be much simpler to use just air, not a liquid and have problems with seals and leaks.
Anyway, induction motor should be called Tesla motor, by its inventor. Germans call motors after their inventor, (but only if he was German) i.e. Otto, Diesel, Wankel (the rotary one), DiesOtto (the new HCCI designs).


Actually it would be much simpler to have solid shaft, but attach a small propeller at one end of motor, which would force air inside axial cavities in rotor. Obviously it's more difficult to cool IM rotors in motors with higher L/D ratio, i.e. long ones.
Is it possible to make some "axial flux induction motors"? I googled the term in quotes - such motors exist, probably there is a good reason they are not used commercially, at least not yet.

AC Propulsion introduced a 75 kW (peak, 27 kw continuous) version of their motor - it was about time.


The problem with air cooling is that air passages are bulky and require volume that doesn't carry magnetic flux, reducing motor power.  There's also the power required to pump the air.

Liquid cooling (or heat pipe) takes a lot less space, allowing the motor to remain compact.


All components of electric drive systems will be progressively improved year after year during the next 20+ years until system efficiency reach 90+%. ICEVs will try to catch up but they never will.


One way to cool an induction motor is to take a carving knife and chop one in half. The two half motors will run cooler.

I may have made this point before on this site anyway here goes. Generally the power of a machine varies with the cube of its linear dimension. The surface area for cooling only increases with the square. Simply put, big things run hot, smaller things not so much.

If we preserve the identical L/D ratio amongst these different sizes we can say that two motors will have 26% more surface for cooling than the equivalent single motor. Or we can turn relation this inside out and state that for the same surface temperature we may run the half sized machines 26% harder. Materials previously producing 40HP can now produce 50.8HP

Multiplicity of motors works even better when the 40HP motor is divided four ways. I'll leave the reader to compute.


Oops ! I managed two typos needing correction in this paragraph-

Or we can turn this relation inside out and state that for the same surface temperature we may run the half sized machines 26% harder. Materials previously producing 40HP can now produce 50.4HP

@Engineer-Poet re heat pipes. Around 1973 the USARMY issued a contract with the objective of using heat pipes as an integral part of the rotor bars. The results as I interpreted them didn't appear encouraging so I discarded the report.


Maybe someone has developed an improved heat-pipe cooling method in the last 40 years.

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