DC motor - Speed torque curve
DC motor - Speed torque curve
(OP)
I beleive the speed torque curve of a DC motor is different from a AC motor. Why is this so?
Do any one have typical Speed torque curve of both DC motor and pump?
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DC motor - Speed torque curve
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RE: DC motor - Speed torque curve
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If we learn from our mistakes I'm getting a great education!
RE: DC motor - Speed torque curve
There are different DC motor characteristics and different AC motor characteristics. But, in practical use, they can be regarded as almost identical.
It is only when you get above the break-down torque that they differ and have very different characteristics. As Scotty says, find a text-book and do some studying.
Gunnar Englund
www.gke.org
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100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...
RE: DC motor - Speed torque curve
Separate [independent] excitation, shunt excitation, series excitation and combined excitation.
For information only, the Torque-speed relations may be considered as follows:
Separate [independent] excitation or shunt excitation:
n[rpm] =Ua/(Ke*Phi)-Ra*Torque/(KT*Phi) –linear function
Ua=rotor voltage
Phi=magnetic flux
Ra=rotor resistance
Series excitation:
n=Ua/(K1*sqrt(Torque)-(Ra+Re)*K2- it is a hyperbole [aproximate]
The combined excitation characteristic is an intermediate curve.
For AC Induction Motor one may use this formula:
Torque=2*MaximumTorque/(s/sk+sk/s)
s [slip]=(nsynchron-n)/nsynchron
sk is the slip corresponding to maximum Torque.
See the attachment for illustration