Quote:
Originally Posted by Paul Copioli
at high current (aka, near stall), the magnetic field saturates producing less actual torque than ideal...However, it is not the only difference.
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Thanks Paul. I think that completes the explanation.
"Kt equals Ke" is a theoretical result which is only approximately true for real-world motors.
Firstly, the "linearity" (straight lines) assumption (
notice the asterisks) used to compute Kt would not be valid when the magnetic field saturates.
Second, "
other_losses" such as bearing friction, windage & viscous damping, eddy currents, and hysteresis in the power equation account for the difference between Ke and Kt.