How can i calculate resistance offered by induction motor when in star and delta connection and if I know winding pattern, power of a motor and number of poles?
Electrical – How is resistance of the induction motor calculated if we know power of motor, winding pattern, and pole of a motor
induction motor
Related Solutions
A standard 3-phase, AC motor has the stator windings distributed in the slots to form poles that do not have much saliency. A switched reluctance motor has both salient rotor poles and salient stator poles. You would need to rewind the stator to have a motor like that.
A synchronous reluctance motor has a salient-pole rotor, but distributed windings in the stator to form non-salient poles. To convert an induction motor to a synchronous reluctance motor, you could use the stator as it is and machine the rotor to look something like this:
You can get some induction-motor starting torque from the remaining rotor bars, but the best way to operate the motor would be with a variable-frequency drive (VFD). The VFD will provide reluctance torque from stand-still. That may or may not suit your purpose.
Of course, you may have some difficulty with rotor balance.
20 kW is the rated mechanical output power. The actual operating power depends on the load. Subtract the core loss and the stator copper loss to get the air gap power (the power transferred from the stator to the rotor across the air gap). Subtract the rotor copper loss, friction and windage (air drag) losses from the air gap power to get the mechanical power delivered to the load in watts (746 W = 1 Hp).
You are correct; n < ns indicates operation as a motor. If n > ns, you would add the losses to the electrical power instead of subtracting and the electrical side figures would be the output and the mechanical side would be the input.
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Best Answer
The effective impedance of an induction motor varies with load, applied voltage and frequency. If you don't know the full-load current and power factor determined by the manufacturer, you can not calculate them. To determine the values of motor's equivalent circuit components, no-load and locked rotor tests must be performed. Various versions of the step-by-step procedure can be found on the internet.