PREPARED BY: Group-D Ramavat Nikunj (140543111003) Synchronous Machines PREPARED BY: Group-D Ramavat Nikunj (140543111003)
Synchronous Machine Outlines: Introduction Construction Working principle Types of Synchronous Machine Comparison between cylindrical rotor type alternator and Salient pole rotor type alternator
Introduction A synchronous machine is an AC machine whose speed is proportional to the frequency of armature current. A machine which rotates at a speed fixed by the supply frequency and the number of rotor poles is called synchronous machine. It always runs at synchronous or constant speed and has no slip. Synchronous machine includes synchronous generators and synchronous motors.
Costruction
Construction Stator:- An alternator cosists of two main parts; 1) Stator and 2) Rotor Stator:- The stator is the stationary parts part of the alternator . It works as a armature in synchronous machine. The armature winding is housed in it.
Construction Rotor: Rotor is the rotating part of the synchronous machine. It work as a field of the synchronous machine. Field system is rotating in the synchronous machine. Field winding is housed on it. Field winding is excited by DC supply through brushes and slip ring.
Working Principle It works on the principle of Electromagnetic induction In the synchronous generator field system is rotating and armature winding is steady. Its works on principle opposite to the DC generator High voltage AC output coming from the armature terminal
Types of Alternator Cylindrical Rotor Type:- Synchronous generators are classified in two category according to its rotor construction: 1) Cylindrical Rotor Type 2) Salient pole rotor type. Cylindrical Rotor Type:- This type machines are High speed machines. (1000 to 3000 RPM) This type machine has Small diameter and is large axial length. This type of machines are used in Thermal power plant and gas turbine power plant. Where speed requires high.
Cylindrical rotor
Cylindrical rotor
Cylindrical rotor
Cylindrical rotor & Salient pole rotor
Types of Synchronous Machine Salient Pole Rotor type Salient Pole rotor type machine: This type machines are Low speed machines.(50 to 500RPM) This type machine has Large diameter and is small axial length. This type of machines are used in Hydro power plant. Where speed are very low.
Salient pole rotor
Salient Pole rotor
Salient pole rotor
Salient Pole Rotor
Salient pole rotor
Stator of Synchronous machine
Stator of synchronous machine
Stator of Synchronous machine
Stator of Synchronous Machine
cylindrical rotor & Salient pole rotor Cylindrical rotor does not have poles that are projecting out. The air gap between the stator and rotor is uniform. The smooth cylindrical rotor has small no of poles. Cylindrical rotors are mechanically strong. They have small diameters and large axial length. The prime movers used are steam turbines and electric motors. They are preferred for high speed alternators which range from 1000 to 3000 RPM
cylindrical rotor & Salient pole rotor Salient pole rotor does have poles that are projecting out from surface. The air gap between the stator and rotor is non-uniform. The salient pole rotor has large no of poles. Saline Pole rotors are mechanically weak. They have large diameters and small axial length. The prime movers used are IC engines and law speed turbine. They are preferred for high speed alternators which range from 50 to 500 RPM
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