Why is there the need for a DC power supply to the rotor? What is the major diff
ID: 2081827 • Letter: W
Question
Why is there the need for a DC power supply to the rotor? What is the major difference between the role of this DC power supply and the one for the armature (rotor) in the DC motor starter circuit?
Disconnect Slip Ring OL, and Brush Fuse Rotor Pbase Winding OL, Power Note: Rotor Stator Fuse winding includes Windings an induction motor winding to get motor up to OL Fuse Slip Ring and Brush Fuse Fuse Fuse Stop OL Start ME variable DC Power Supply TD TD Circuit connected to the secondary of the transformer (lower portion) is for control purpose. Explanation of the symbols: TD: On Delay Timer. After a preset time delay the TD contacts supply power to the DC rotating magnet.Explanation / Answer
Why there is a need of DC supply to rotor?
Field winding is an essential part of a motor/generator which is considered as an energy converting device which is converting electrical energy into mechanical energy in case of a motor and vice versa in case of a generator/alternator.
The DC excitation provides a steady (constant) magnetic field in the rotor. As the rotor spins, the steady field becomes a rotating output. Steady rotor electromagnetic field (from DC excitation) becomes rotating (or AC) output voltage. It can be understood in DC the value of potential difference between the two wires will be in its peak (-) or (+) value, but if the average value of the AC is calculated, it will be always zero since it varies between (-) and (+) of its maximum value, hence the value of DC will be constant at any fraction of time where as in case of AC it will always vary and if this varying power supply is give to aid the electro-mechanical energy conversion process as excitation, the torque/EMF generation will not be constant and may be even inadequate for its operation and the torque/EMF will be constantly changing the direction which will eventually produce huge amount of hysteresis loss with an non-operational electrical device.
** The only differenc in role of DC supply used for both cases are, the DC supply used at starting for limiting starting current and torque using different techniques wherease, the othe DC supply provided static magnetic fielfd to rotor (armature)
Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.