DESIGN OF DAMPER WINDING ||DESIGN OF ELECTRICAL APPARATUS (DEA)

ROHINI COLLEGE OF ENGINEERING & TECHNOLOGY


5.6 DESIGN OF DAMPER WINDING

 Damper windings are provided in the pole faces of salient pole alternators.

Damper windings are nothing but the copper or aluminum bars housed in
the slots of the pole faces.
 The ends of the damper bars are short circuited at the ends by short circuiting

rings similar to end rings as in the case of squirrel cage rotors.
 These damper windings are serving the function of providing mechanical

balance; provide damping effect, reduce the effect of over voltages and
damp out hunting in case of alternators.
 In case of synchronous motors they act as rotor bars and help in self-starting

of the motor.
Design Procedure:
 MMF of Damper Winding = 0.143 ac τ
Where,
ac – specific electrical loading
τ- Pole pitch
 Total area of damper winding Ad = 0.2 ac τ /δd
Where,
ac – specific electrical loading
τ- Pole pitch
δd - Current density
 Cross-sectional area of each damper winding ad= Ad/Nd
Where,
Ad – Total area of damper winding
Nd - Number of damper bars
Pole arc
 Number of damper bars Nd =
0.8∗Stator slot pitch

 Diameter of each damper bar Dd = 4ad
√
𝜋
 Length of each damper bar Ld = 1.1 L


EE8002 DESIGN OF ELECTRICAL APPARATUS