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Damper winding is used to suppress the vibrations in the rotor. As cylindrical rotor has no projections and there is a closed portion to contain field winding which is distributed. Therefore it acts as a smooth rotor. It does not require any damper winding as the smooth rotor it self acts as good damper.
What is the necessity of damper winding?
Damper windings helps the synchronous motor to start on its own (self starting machine) by providing starting torque. By providing damper windings in the rotor of synchronous motor “Hunting of machine”can be suppressed.
Why do salient pole rotors need damper?
Salient pole rotors generally need damper windings to prevent rotor oscillations during operation. Salient pole synchronous generators are mostly used in hydro power plants.
Where is damper winding used?
The damper winding (also known as ammortisseur) is mostly used in synchronous machine- in stator of synchronous generator and rotor of synchronous motor. It provides some specific advantage to synchronous machines like – smooth starting and compensating the transient effect or unbalanced condition.
Why damper winding is provided in alternator?
Damper winding in an alternator is also known as squirrel-cage winding. This winding is located inside the slotted pole shoes of the alternator. Prevents hunting (momentarily speed fluctuations) in the alternator, Increases the transient stability.
What is a damper winding?
: a short-circuited squirrel-cage winding placed in the pole faces and around the pole shoes of synchronous machines, the currents induced in the winding by the periodic variations in synchronous speed having the effect of a damper. — called also amortisseur.
How does a damper winding work?
synchronous motors usually referred to as a damper winding because of its additional property of damping out any oscillation that might be caused by sudden changes in the load on the rotor when in synchronism. Adjustment to load changes involves changes in the angle by which the rotor field lags the stator….
Which kind of rotor is most suitable for turbo alternators which are designed to run at high speed?
Smooth cylindrical type rotor is generally used for high speed alternators or turbo alternators.
Which type of rotor is suitable for low speed alternators?
The salient pole type of rotor is generally used for slow speed machines having large diameters and relatively small axial lengths. The poles, in this case, are made of thick laminated steel sections riveted together and attached to a rotor with the help of joint.
Why are round rotor synchronous machines used at high speeds?
Since the rotor can be balanced easily and centrifugal forces will be evenly distributed, the rotor of the round (cylindrical) rotor generator can be run at higher rotational speed.
How is damper winding used to reduce hunting?
Use of Damper Winding: It consists of low electrical resistance copper / aluminum brush embedded in slots of pole faces in salient pole machine. Damper winding damps out hunting by producing torque opposite to slip of rotor. This increases the inertia of prime mover and helps in maintaining the rotor speed constant.
What is the use of damper?
A damper is a valve or plate that stops or regulates the flow of air inside a duct, chimney, VAV box, air handler, or other air-handling equipment. A damper may be used to cut off central air conditioning (heating or cooling) to an unused room, or to regulate it for room-by-room temperature and climate control.
What is the basic principle of alternators?
All the alternators work on the principle of electromagnetic induction. According to this law, for producing the electricity we need a conductor, magnetic field and mechanical energy. Every machine that rotates and reproduces Alternating Current.
Which supply is given to synchronous motor?
The operation of a synchronous motor is due to the interaction of the magnetic fields of the stator and the rotor. Its stator winding, which consists of a 3 phase winding, is provided with a 3 phase supply, and the rotor is provided with a DC supply.
How synchronous motor works as a power factor correction?
The power factor of a synchronous motor is changed with a change in the excitation. When the excitation of the motor is increased, the power factor changes from lagging to unity and then to a leading power factor.
What does the power factor of an alternator depend on?
The power factor of the alternator depends upon the type of load. In case if it is an infinite bus, then the power factor of the alternator depends upon the excitation of the alternator. According to load, the alternator provides both reactive (kVAR) and real power (kW).
What is the slip speed?
The speed at which the induction motor work is known as the slip speed. The difference between the synchronous speed and the actual speed of the rotor is known as the slip speed. In other words, the slip speed shows the relative speed of the rotor concerning the speed of the field.
What are the causes of hunting?
Various Causes of Overhunting Overpopulation. Cosmetic Products. Overhunting For Food. Growing Demand For Animal Meat. Tradition and Culture. Hunting For Fun or Sport. Hunting For Fur, Decoration and Other Economic Values. Increased Affordability.
What is Amortisseur winding?
amortisseur winding (plural amortisseur windings) A squirrel cage winding placed near the surface of the pole faces of a synchronous motor. Its main purpose is to dampen any speed fluctuations or oscillations that may occur as a result of sudden load changes.
What are the methods used for starting of synchronous motor?
Damper Windings is the most widely used method to start a synchronous motor. A Damper Winding consists of heavy copper bars inserted in the slots of the pole faces of the rotor as shown in the figure below. These copper bars are short-circuited by end rings at both ends of the rotor.
How does a 3 φ synchronous motor start?
A three-phase synchronous motor has no starting torque. Once up to speed, the rotor field can be excited with direct current and the rotor is, in effect, then dragged around at the same speed as the three-phase stator field. Its speed is synchronized with that of the stator field.
Which type of starter is used for synchronous motor?
Controllers for synchronous motors have four components: a three-pole starter for the ac stator circuit, a contactor for the dc field circuit, an automatic synchronizing device to control the dc field contactor, and a cage-winding protective relay to open the ac circuit if the motor operates too long without.
