Table of Contents
- 1 How is the polarity of the Interpoles in DC machine determined?
- 2 What do Interpoles do in a DC motor?
- 3 What current flows through Interpoles?
- 4 What is the difference between Interpoles and compensating windings?
- 5 What is the polarity of Interpoles in reference to the polarity of main field poles in a direct current motor?
- 6 Does the direction of rotation of DC shunt motor would get reversed if the armature current and field current Both are reversed?
- 7 What is the polarity of Interpol in DC motor?
- 8 What is the polarity of the interpoles in a generator?
- 9 What is interpole winding in DC generator?
How is the polarity of the Interpoles in DC machine determined?
Polarity of an interpole depends on the direction of rotation. Armature rotation is clockwise as viewed from the commutator end of the motor. FIGURE 7-46. Effect of interpoles on the magnetic flux field of a DC motor.
What do Interpoles do in a DC motor?
The interpole prevents the armature and brushes from arcing due to the buildup of magnetic forces. These forces are created from counter EMF called armature reaction. They are so effective that normally all DC compound motors that are larger than 1/2 hp will utilize them.
What current flows through Interpoles?
What current flows in the interpole windings? The DC motor is reversed by reversing the direction of the current in the armature. When the armature current is reversed, the current through the interpole is also reversed. Therefore, the interpole still has the proper polarity to provide automatic commutation.
Why Interpoles are tapered in a DC machine?
The interpoles in dc machines have a tapering shape in order to reduce the saturation in the interpole. Wave winding has two parallel paths where lap winding has parallel paths equal to the number of poles.
What is the polarity of Interpoles in DC motor?
Interpoles are narrow poles placed at the GNA and fitted to the Yoke and also known as Commutating Poles or Compoles. For generator, the polarity of Interpoles must be same as that of main Pole ahead of it in the direction of rotation. For Motor, the polarity of Interpole must be same as that of Main Pole behind it.
What is the difference between Interpoles and compensating windings?
In order to neutralize the cross magnetizing effect of armature reaction, a compensating winding is used. 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.
What is the polarity of Interpoles in reference to the polarity of main field poles in a direct current motor?
Does the direction of rotation of DC shunt motor would get reversed if the armature current and field current Both are reversed?
When both (the direction of field as well as that of armature current) are reversed the direction of rotation will not change. So in case of DC shunt motor, if the supply terminals are interchanged, there is no change in direction of rotation.
Why is the armature of a DC machine made of silicon steel?
An a armature winding of DC motor is connected to a rotating part of the machine called rotor. It goes through an alternating magnet field. This results in magnetic losses. Because of magnetic losses, rotor is built using armature core which in turn is made with many low-hysteresis silicon steel lamination.
What is inter pole?
Definition of interpole : a supplementary pole placed between the regular poles of a direct-current dynamo or motor in order to regulate commutation. — called also commutating pole.
What is the polarity of Interpol in DC motor?
For DC motor Polarity of an interpole depends on the direction of rotation. The interpole’s polarity will always be the same as that of the main pole which precedes it. What is the difference between the function of work in Interpol and the compensating winding in a DC machine?
What is the polarity of the interpoles in a generator?
Polarity of interpoles are same as the main pole just ahead in the direction of rotation of machine in generator . In motor it is just reverse , i.e same as the main pole just behind.
What is interpole winding in DC generator?
Interpole Windings in DC Generator Interpoles are wound and placed so that each interpole has the same magnetic polarity as the main pole ahead of it, in the direction of rotation. The field generated by the interpoles produces the same effect as the compensating winding.
What is the purpose of interpoles in DC machine?
Purpose of Interpole in DC Machine. For understanding the role of Interpoles, we need to understand the effect of armature reaction in the DC Machine. The effect of armature mmf on the main field flux is to distort the main field flux and to reduce the net main field flux. The figure below, shows the effect of armature mmf on the main field flux.