Question: What Is Damper Winding In Synchronous Generator?

Definition of 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 the role of damper winding in synchronous generator?

The primary function of damper winding in a synchronous machine is to prevent the phenomenon called hunting. In case of synchronous motor, damper winding performs an additional function. It acts as a squirrel cage winding and makes the synchronous motor self starting.

What is the role of damper winding in alternator?

Damper winding in an alternator is also known as squirrel cage winding. This winding is located inside the slotted pole shoes of alternator. Prevents hunting (momentarily speed fluctuations) in alternator, Increases the transient stability.

How does damper winding prevent hunting?

The function of the damper winding in the synchronous generator is to suppress the negative sequence field and to dampen oscillation whereas it is used to provide starting torque and reduce effect of hunting to some extent in the synchronous motor.

Why damper bars are used explain its significance?

The bars are connected to each other at both ends of the rotor by so called end-rings. Damper windings are used to counteract an asynchronous air- gap flux which can be caused by electrical and mechanical transients [4]. They are also used to bring the machine to synchronous speed in direct-online applications.

What is synchronous reactance?

The Synchronous Reactance (XS) is the imaginary reactance employed to account for the voltage effects in the armature circuit produced by the actual armature leakage reactance and by the change in the air gap flux caused by the armature reaction.

What is synchronous speed?

In a motor, synchronous speed is the speed at which the magnetic field rotates. Depending on motor design, the actual mechanical speed may be equivalent (synchronous motor) or slightly smaller (asynchronous motor). The synchronous speed is a function of:The electrical frequency used, typically 60 Hz or 50 Hz.

What is meant by synchronous condenser?

In electrical engineering, a synchronous condenser (sometimes called a synchronous capacitor or synchronous compensator) is a DC-excited synchronous motor, whose shaft is not connected to anything but spins freely.

Why damper winding is used in induction motor?

Hence the hunting reduces quickly due to damper winding. When the rotor is rotating at synchronous speed, then the relative velocity between the RMF (rotating magnetic field of stator) and the rotor is zero. Hence induced EMF in the damper winding is zero.

What are damper windings?

Definition of 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 synchronous motor start?

Starting a Synchronous Motor Using Damper Windings

The ends of the copper bars are short-circuited. These windings behave as the rotor of an induction motor. When 3 phase power is supplied to the motor, the motor starts running as an induction motor at a speed below synchronous speed.

Why synchronous motors are not self starting?

Key Point : As a result, the average torque exerted on the rotor is zero. And hence the synchronous motor is not self starting. This is because the speed with which rotating magnetic field is rotating is so high that it is unable to rotate the rotor from its initial position, due to the inertia of the rotor.

What is the application of synchronous motor?

usually, synchronous motors are used for applications where precise and constant speed is required. Low power applications of these motors include positioning machines. These are also applied in robot actuators. Ball mills, clocks, record player turntables also make use of synchronous motors.

What is a salient pole?

Definition of salient pole. : a magnet pole that projects toward the armature of an electric machine — compare consequent pole.

What is damper bar?

The damper winding consists of short circuited copper bars embedded in the the face of the rotor poles When an ac supply is provided to stator of a 3-phase synchronous motor, stator winding produces rotating magnetic field. The exciter for synchronous motor moves along with rotor.

How can synchronous motor be stopped?

Most popular and effective method to stop a motor is first apply electric braking to reduce the speed and then apply mechanical brakes till the speed is zero. This is done because at lower speed mechanical brakes produce less heat.