Synchronous motor & Alternators application

An Application of 3 phase synchronous motor
Construction of 3 phase alternator

1. Group-iv Presentation by Matthias Gyamar Deba nika Taj atu

2. Contents 1. An application of 3 phase synchronous motor 2. Construction of 3 phase Alternator

3. application of 3 phase synchronous motor Defination A 3-phase synchronous motor is a 3-phase synchronous machine which is operated as a motor i.e. Converts electrical energy input into mechanical energy output.
A synchronous motor has a unique feature that is it runs at a constant speed equal to the synchronous speed at all load provided that the load on the motor does not exceed the limiting value. If the load on the motor exceeds the limiting value, then the motor will come to rest and the average torque developed by the motor becomes zero. Because of this, a synchronous motor is not inherently self-starting.

4. Synchronous motors are normally used in applications in which a constant and precise speed is required. Typical applications of these low power motors are positioning machines.

5. Types of 3 phase synchronous motor application are :- Fan

6. 2. Air blower

7. 3. Paper mills

8. Construction of 3 phase Alternator Definition An alternator is a type of generator that converts mechanical energy into electrical energy. The output of the generator can be either alternating current AC or direct current DC.

9. Unlike DC generator that has rotating armature winding and a stationary magnetic field. The alternator is made of a stationary armature winding and a rotating magnetic field. The field windings are placed in the rotor while the armature windings are placed in the stator.

10. Construction of 3 phase Alternator An alternator has 3,-phase winding on the stator and a d.c. Field winding on the rotor. 1. Stator It is the stationary part of the machine and is built up of silicon
steel laminations having slots on its inner periphery. A 3-phase
winding is placed in these slots and serves as the armature
winding of the alternator. The armature winding is always
connected in star and the neutral is connected to ground.

11. 3 phase Alternator stator consist of Stator frame/Yoke Stator core Stator winding Stator frame/Yoke :- The stator frame is the outermost part of the alternator. It is made up of cast iron or cast steel or welded steel plates. It encloses all the parts of the alternator from entering dust. It also holds the stator core and winding in proper position and gives mechanical protection to the entire machine.

12. Stator core :- The stator core is the stationary part of the alternator. The structure of the stator core is similar to the dc armature core with silicon steel (steel alloy) laminations. The inner periphery of the laminated stator core consists of slots to accommodate three-phase armature conductors. The stator winding (armature winding) is placed in the slots.

13. Stator Winding or Armature Winding :
Armature winding is made up of insulated copper or aluminum conductor placed in stator core slots. These stationary conductors when cut by the magnetic field emf get induced in them. Basically, the armature of an alternator consists of three-phase winding either in star or delta connection.

14. 2. Rotor The rotor carries a field winding which is supplied with direct current through two slip rings by a separate d.c. Source. This d.c. Source (called exciter) is generally a small d.c. Shunt or compound generator mounted on the shaft of the alternator.Rotor construction is of two types, namely;
1. Salient (or projecting) pole type 2. Non-salient (or cylindrical) pole type