MOTORS – convert electrical energy to mechanical energy
Motors and generators are the most frequent used electrical machines.
❖ Generators action can take place when and only when, there is a relative motion between conducting wires and magnetic lines of force.
❖ Electric motor is in operation when it is supplied with electrical energy and develops torque, that is, a tendency to produce rotation.
❖ In DC generator, the armature winding is mechanically rotated through the stationary magnetic fields created by the electromagnets or permanent magnets.
❖ In AC generator, the electromagnets or permanent magnets and their accompanying magnetic fields are rotated with respect to the stationary armature windings.
Classification of single phase motors
1. Shaded pole
Classification of Poly phase Motors
1. Induction Motor
2. Commutator (Schrage Motor)
Commutation on DC Motor
The function of the commutator and the brushes in DC motor and generator is to act as an inverter, that is to change direct current to alternating current.
DC Generator and DC Motor
A dc generator and a dc motor are identical in structure and are interchangeable. Any dc motor can be used as a generator, and any dc generator can be used as motor with only a minor change in connections. When a conductor (wires of the armature) cuts the lines of force (magnetic field of the stator), a voltage is generated in that conductor (wires of the armature). There are three factors or rules that govern the amount of voltage generated: 1. The number of lines of force being cut.
2. The speed at which the conductors...