I am sure this has been answered somewhere, but I cannot find it so here goes in hope.
For an average mid size compact 4 door car, is a surplus industrial 3 phase motor suitable for an EV?
If so what sort of size and power rating would be considered as good.
So far I have seen 3HP, 5HP and 10HP advertised would any of these be considered suitable?
regards John
Hi John,
I'm relatively new to the world of EVs, but here's what I've gleaned. To keep a car moving at a constant velocity, you need to overcome two main opposing forces -
Rolling resistance and air resistance (or drag) . Drag is particularly important at higher velocities, since it increases exponentially with speed.
Still, for a small relatively aerodynamic car like a Toyota Corolla, the power required to overcome those two forces at 65mph is only about 20hp.
Acceleration however, is a completely different kettle of fish. You may need 3x or even 4x the 20hp to get decent acceleration.
I assume the motors you are speaking of are 3 phase AC. I don't think you can safely increase their power output by simply increasing the voltage you run them on.
However, you can safely "over volt" a series wound DC motor. Hence the popularity of DC series wound motors with EV enthusiasts. Used forklift motors
are ideal candidates because they are usually DC series wound, they are cheap and they are easy to find.
Hope this helps,
Greg.