02/03/2021

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

 

 

You may also like :

Compare : Squirrel Cage Induction Motor – Synchronous Motor

Compare : Salient Pole Alternator – Cylindrical Pole Alternator

Earthing Transformer : Construction and Working

Hysteresis Motor : Construction, Working, Characteristic, Applications 

 

No comments:

Post a comment