Speed of a Cumulative Compound DC Motor


by mobin.abrar
Tags: compound, cumulative, dc motor, electric machines, torque-speed
mobin.abrar
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#1
May6-12, 04:44 AM
P: 1
I came across an equation for the Speed ω in Radians/seconds of a Cumulative Compound DC motor.

ω= K(Vt-IA[RA+RF)/([itex]\Phi[/itex]P+[itex]\Phi[/itex]S)
  • How would we calculate K in this equation?
  • Shouldn't the Terminal Voltage Vt be replaced by Armature Voltage Ea?
  • I came across a lot of varying torque speed curves. WIll the curve be exponentially decaying or linear?
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#2
May6-12, 09:16 AM
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P: 10,854
Maybe you should explain your formula and the used variables, or at least give its source.
My guess: K is some constant given by the geometry of the motor.

I came across a lot of varying torque speed curves. WIll the curve be exponentially decaying or linear?
I don't think that any of these curves are perfectly exponentially or linear. In addition, it might depend on the motor (e.g. how its internal friction depends on the angular velocity).


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