MEEN 225- Final Exam Guide - Comprehensive Notes for the exam ( 82 pages long!)
28 Mar 2018
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Document Summary
The type of dc machines is classified according to the way in which their fields are excited: separately excited and self-excited. When the dc field current is supplied by an external source, the machine is said to be separately excited. There is no direct connection between field & armature circuits. Equivalent circuit for a separately excited dc motor is given as below: There is a direct connection between the armature and the field winding. The armature winding will provide the current to create the magnetic field. It may be classified as: series excitation. Field winding is connected in series with the armature winding: shunt excitation. Field winding is connected in parallel with the armature winding: compound excitation. Field winding is connected in series & parallel with the armature winding. The equivalent circuits for self-excited dc motors are given as follows: In general, pin = pout + losses and the losses are given as follows:
