Why is compensating winding necessary?

The main purpose of compensating winding is to nullify the effect of armature reaction on the main field flux under the pole faces in DC machine. Due to the effect of armature reaction mmf, the flux distribution under the pole faces is distorted which leads to poor commutation and flashover.

Why do we need a compensating winding in DC machines How is this winding excited and why?

The cross-magnetizing effect of armature reaction may cause trouble in d.c. machines subjected to large fluctuations in load. In order to neutralize the cross magnetizing effect of armature reaction, a compensating winding is used.

What is Series AC motor?

AC Series Motor is a commutator-type motor which is able to work on both dc and single phase ac supply. If an ordinary dc series motor is connected to an ac supply, because of simultaneous reversal of field and armature currents, it will develop a unidirectional torque and as a result of this, its armature will rotate.

What is meant by compensating winding?

Definition of compensating winding : a winding embedded in the pole faces of a commutating alternating-current or direct-current machine and connected in series with the armature, the magnetic field of the winding neutralizing the cross-magnetizing field of the armature.

Where is compensating winding placed?

pole faces
Compensating winding is embedded in the slots in pole faces. It is connected in series with the armature winding so that their mmfs are proportional to the same current.

Why efficiency of an AC series motor is low?

The efficiency is low. This is because of the increase in core losses due to alternating flux. The reactance of the field and armature winding increases as the supply given is alternating, which makes the machine run at a low power factor.

What is the exact location of compensating winding?

Compensating winding is located on the pole shoes of DC machines.

For which of the following purposes are compensating winding used in DC generator?

Compensating winding are used in DC machines to neutralize the cross magnetizing effect of armature reaction. The machines which are subjected to large changes in load will experience the sudden shift in magnetic neutral axis.

For which of the following purposes are compensating windings used in DC generator?

What is the most serious disadvantage of compensating windings?

The main disadvantage of compensating windings is that they are expensive since they must be machined into the faces of the poles. Also, any motor with compensative windings must have interpoles to cancel L di/dt effects which occurs in the commutator segments being shorted out by the brushes due to current reversal.

When a universal motor is operated on AC and the compensating winding is connected in series with the armature it is known as Compensation?

The axis of compensating winding is 90 degrees with the main field axis. The compensating winding is connected in series with both the armature and the field, hence, it is called Conductively compensated. The construction of the universal motor is the same as that of the series motor.

What is a compensating winding in a motor?

In this type of motor, the compensating winding has no interconnection with the armature circuit of the motor. In this case, a transformer action will take place as the armature winding will act as primary winding of the transformer and the compensation winding will acts as a secondary winding.

How are Compensating windings connected in series?

The compensating windings are connected in series with each other and with the armature winding in a manner similar to the interpole windings so that they also oppose the field set up by armature reaction. The current in them is then equal to that in the armature.

What are the Compensating windings of a DC machine?

The compensating windings consist of a series of coils embedded in slots in the pole faces. These coils are connected in series with the armature. Compensating Windings and Interpoles in dc machine The series-connected compensating windings produce a magnetic field, which varies directly with armature current.

What is an inductive compensated motor?

In this type of motor, the compensating winding is connected in series with the armature circuit. The winding is put in the stator slots. The axis of the compensating winding is 90 o (electrical) with main field axis. Given below is the circuit diagram of the inductively compensated type of motors.