I'm interested in investing in UQM and would like to hear your opinion on their new product the PowerPhase125.
In quantities of over 200,000/year they are quoting a price of $1418 for both the motor and controller. I'm not an expert but their spec sheet seems to address many of the concerns you've raised about DC motors. Is this a viable alternative for a mass produced EVs?
Hi, Tom - Is it a viable alternative? Yes, I think it is.
Toyota must have thought so, too, because this is the same type of motor they put in their Rav-4 EV back in the day.
The UQM Powerphase motors are brushless per-mag motors which - as I look at the spec sheet (pdf) - have qualities of the AC motor and also qualities of the DC motor. The torque curve looks like a typical golf cart motor, but when powered by 300 or so volts, it just feels like a rocket. Who cares that it tops out at 75 mph or thereabouts?
I really, really like what little I've seen so far - like this gorgeous Lotus Elise conversion with the UQM Powerphase 75 inside. (The difference between the 75 and the 125 is that the 125 is more powerful - but basically the same motor.)
As far as investing based on my opinion? I really liked Phoenix Motorcars and those Altair NanoSafe batteries, too - didn't keep them from going bankrupt. Shows you what I know; )
What are the advantages of Radial flux AC induction motors? From what I have read, Axial flux motors have a higher efficiency and lower volume per power and energy basis. Is it just the dimensions that inhibit them from being more widely used?
Hi, Tom - I'm sorry, but I have no idea. Axial flux motors, I've heard of them being used in hub motor applications, as in the video above...but I'm not familiar with radial flux motors.
I may be showing my ignorance, but I believe brushless DC motors run on three phase AC. Why is it called a DC motor?
Well... Brushless DC motors run on batteries when you put them in an electric car, and 3-phase AC induction motors do the same. That's not the part that makes classifies them as AC or DC electric motors.
Brushless DC (BLDC) motors DO look and act a lot like 3-phase AC induction motors - including needing a more complicated controller than a series wound DC motor - but the torque curve of a BLDC motor is more similar to a permanent magnet DC motor (because that's basically what it is), and induction (slip) doesn't generate torque as it does in a 3-phase AC induction motor.