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Originally Posted by MPaulHolmes
Could I get 6-8 times the full load current for 10 seconds? I think I'll wrap the LEM 300 current sensor a few times to reduce the 300 down to maybe 100 (3 wraps).
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Yes, you should be able to get 6X - 8X current on a stall. You can go longer than 10 seconds but at some point you risk damage to the insulation on the windings.
If you can fit 3 wraps of wire through the sensor - I'd try that.
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And I was thinking that if it's supposed to be more powerful than the 144v 500amp DC controller, then it better be at least 288vDC input, with 300amp per phase (since the IGBTs can handle that). Now I'm seeing all these AC motors that weigh 5 gazillion pounds, that are rated for like 20 amps. Are we stuck with AC motors whose peak power is much lower than 100kW if you want to actually fit it in a car?
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The AC motors appear to increase the voltage and reduce the current. I use EVTV as examples, but there are many vendors.
EVTV Motor Verks Store:
The Siemens motors that Azure Dynamics had made for them were 300V and 400A? With voltage sag on the pack about 100 kw. These are expensive for the DIYers, but appear to be well suited for vehicles.
Three phase electric motors for commercial or industrial use are rated for continuous duty. That appears to be why they are so large and heavy but have little horsepower. Their power limit is defined by how much heat they can get rid of in a 24/7 situation.
Since we, in an EV, only have enough battery for maybe an hour of driving and then the motor cools down all day while we are at work ... you can push the performance higher with lower weight. HPEVS has several motors that are physically quite small, but decent horswepower. HPEVS want to sell their motors as a package with the Curtis controller ... at least, that's how I see them advertised.
Another issue is the rotor design of an induction motor. We have some people in this group that have much more expertise in this area than I do. The summary is that induction motors have different 'sets' of rotor bars at different 'depths' from the surface of the rotor. Some are important for 'across the line' or 'direct online' starts. Others are more suited to controllers where there is not much slip. I have been hoping that someone would start to market rotors for the EV market .. to fit in T frame motors .. but I guess that's not a large market?
Heck, if the rotors were higher performance and lower weight, I might even buy them for my day job. We have about 20% of our motors on controllers, so we could use lighter and higher performance (lower slip) rotors. Then our mechanics and electricians would not complain as much about how heavy the motors are when they need to change them.