Relation Between Electric Frequency and magnetic field rotation speed in a motor

[Chacabucogod]

Hi!
I understand that if you have a stator with a a three phase electric signal going into it, both the frqyency and angular velocity of the magnetic field and the electric entry will be the same. Now when you feed it with 2 groups of three phases electric signals you get four poles, or at least that is what the book says. Why does that happen. Why does one pole only go half the way and the other one the other half. I can't quite grasp that idea.

Thank you

 

[gkam44]

Chaca, good question. But each of the three phases is in its own winding. The windings are 120 degrees apart physically (rotationally), too. It is not one winding. I have some stuff I used to teach around here somewhere, if you want help in visualization.

 

[Chacabucogod]

That'd helpful! Thankyou

 

[gkam44]

On short notice, I just looked up "three phase windings" and found some pics. http://www.google.com/url?sa=i&rct=...PV3hQaPUk-5Yzlvnh-IclTkg&ust=1414530506784639

One pic shows how the physical windings are put in the stators, and another shows how the three phases line up 120 degrees apart electrically.

 

[alphy]

for your question. The relation between electric frequency and magnetic field rotation speed in a motor is a complex concept, but I will do my best to explain it in simple terms.

First, it is important to understand that the electric frequency refers to the number of times the electrical signal cycles per second. This is measured in Hertz (Hz). On the other hand, the magnetic field rotation speed refers to how fast the magnetic field created by the electric signal is rotating. This is measured in revolutions per minute (RPM).

In a motor, the electric frequency and the magnetic field rotation speed are directly related. This means that as the electric frequency increases, the magnetic field rotation speed also increases. This is because the electric signal creates a magnetic field that rotates around the motor's stator. As the frequency of the electric signal increases, the magnetic field rotates faster.

Now, let's talk about the concept of poles in a motor. A pole is an area of the motor's stator where the magnetic field is the strongest. In a motor with a single group of three phase electric signals, there are two poles. This means that the magnetic field rotates around the stator, creating two poles that are opposite each other.

When you feed the motor with two groups of three phase electric signals, you are essentially doubling the number of poles. This means that the magnetic field will now rotate around the stator, creating four poles that are evenly spaced. This is why one pole only goes half the way and the other one goes the other half - because the magnetic field is rotating around the stator and creating four poles instead of just two.

I hope this explanation helps you understand the relation between electric frequency and magnetic field rotation speed in a motor. It is a complex concept, but it is essential to understand in order to fully grasp how motors work. If you have any further questions, please don't hesitate to ask. Thank you.