Table of Contents
Functions of Damper Windings: 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.
What is the purpose of damper winding in alternator Mcq?
Damper Winding: A synchronous motor has no self-starting torque. Therefore, damper winding provides starting torque necessary for starting the synchronous motor. It also prevents hunting of synchronous motor, that is it reduces oscillations of the rotor when the motor deviates from synchronism.
What is 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.
What is a damper winding what is the function of it and where it is located?
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….
Where are damper windings?
Damper winding in synchronous machine is placed in the coil slots and short circuited. Thus Damper winding provides the same effect as the squirrel cage winding rotor does in case of induction motor.
Which type of rotor is best for turbo alternator?
Smooth cylindrical type rotor is generally used for high speed alternators or turbo alternators.
What are the advantages of providing 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.
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 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 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.
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.
Why synchronous motors are not self starting?
Above a certain size, synchronous motors are not self-starting motors. This property is due to the inertia of the rotor; it cannot instantly follow the rotation of the magnetic field of the stator. Once the rotor nears the synchronous speed, the field winding is excited, and the motor pulls into synchronization.
Why do we use synchronous condenser?
Technology Types. A synchronous condenser is a conventional solution that has been used for decades for regulating reactive power before there were any power electronics compensation systems. A conventional synchronous condenser is an AC synchronous motor that is not attached to any driven equipment.
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 a damper bar?
The damper bars (or amortisseur windings) in the rotor of direct on-line started SMs is an important component that enables starting of the motor. It also improves the operating stability and motor performance under non-ideal supply conditions and load transients.
Can an induction motor run at synchronous speed?
So, theoretically, the Induction motor can never run at synchronous speed. But due to the reduction of speed, again lag influx will be achieved, and the motor will continue to move at this speed due to flux difference between rotor and stator. In short, an induction motor cannot run at induction speed.
Which kind of rotor is most suitable for alternators which are designed to run at high speed?
177. What kind of rotor is most suitable for turbo-alternators which are designed to run at high speed? 178. The power developed in the alternator having salient type rotor is less than of having non-salient pole.
Which kind of motor is most suitable for turbo alternator which are designed to run at high speed?
Non-salient pole type or cylindrical type rotors are used in high-speed alternators or turbo-alternators having speed between 1500 rpm to 3000 rpm.
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.
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).
Which of the following rotor requires damper winding?
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.
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.
