Performance Question

[eager2own]

Hmm. Okay. Guess I am mistaken then. Most all torque charts I have seen show a flat line from 0 per cent to 100 percent. Maybe I was looking at something different.

Do we have a torque graph for the MME motor? At what RPM does max torque occur

This article does a good job at explaining why torque does decrease at high RPMs:

Torque Article

I haven’t seen the graph for the MME motor, but I expect max torque right away and to be flat at 100% until some RPM — we just don’t know when that is at this point.

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[SnBGC]

This article does a good job at explaining why torque does decrease at high RPMs:

Torque Article

I haven’t seen the graph for the MME motor, but I expect max torque right away and to be flat at 100% until some RPM — we just don’t know when that is at this point.

Thanks. Will give it a read. Always like to learn new stuff.....

 

[FredT]

Not the Mach-e motor, but this is from the IDM video that you posted a link to:

 

[RonTCat]

Not the Mach-e motor, but this is from the IDM video that you posted a link to:

DC electric motors have a synchronous speed based on the number of magnetic poles and input power frequency. At that speed, the back electromagnetic force from the rotor (spinning magnets) is in balance with that of that produced by the static coils (outer, non-spinning) to spin it. For the graph above, that point seems to be 4000 rpm. Synchronous speed is the "max current" condition for the motor, kind of wide open throttle for a dc motor.

The motor experts can chime in, but I don't think any electric vehicle motors operate above synchronous speed. To go above that speed, you have to apply electrical or mechanical field weakening. You are already at max current, so you are really just removing the resistance (back emf) from the rotor field. To weaken the field, you have to do some things with the input power control, all of which reduce power. That's why you see the horsepower decrease above synchronous speed.

Motor experts, please simplify or correct...

 

[ChasingCoral]

This sounds like a good question for tomorrow night's webinar on Performance and Charging.

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