DC Shunt Motor & DC Series Motor
DC Shunt Motor
In the DC Shunt Motor, the armature winding
and field winding are connected in parallel and voltage across it, equal to
supply voltage.
DC Series Motor
In the DC Series Motor, the armature winding and field winding are connected in series and voltage across it, equal to supply voltage.
Compare DC Shunt Motor and DC Series Motor
Series field winding |
Shunt field winding |
The armature winding is series with the field winding |
The armature winding is parallel with the shunt field winding. |
As the series field winding is connected in series with the armature
winding, the series field carries same
current as that of armature winding. |
As the shunt field winding is connected in parallel with the armature
winding, the voltage across shunt field winding is same as the armature
winding. |
The series winding is designed with few turns of thick wires. |
The shunt field winding is designed with large number of turns having
thin wires. |
The resistance of the series field winding is very low. |
The resistance of the shunt field winding is very high. |
The torque is directly proportional to square of the armature current. T α ΦIa As Φ α Ia T α Ia2 The series motor would draw only 1.41 times full load current for the
same amount of torque. ( As t α Ia2 ) |
The torque is directly proportional to the armature current. T α ΦIa As Φ is almost constant T α Ia If twice the full load torque required at start, the shunt motor draws
the twice the full load current. ( As t α Ia ) |
The starting torque develop by series motor is high as compared to
shunt motor for same amount of armature current. |
The starting torque develop by shunt motor is low as compared to series
motor for same amount of armature current. |
A series motor respond by decreasing its speed with small increase in
current for a given load torque. |
A shunt motor holds its speed nearly constant with large increase in
input current for same amount of load torque. |
Variable speed motor |
Constant speed motor |
Applications : Hoists , Cranes , Trolley
cars ,Conveyors, Electric locomotives |
Applications : Lathes , Centrifugal pump ,
Blowers, Machine tools , Printing process , Spinning
machines, Reciprocating pump |
No comments:
Post a Comment