# How to design a 3 phase induction motor

1. Aug 13, 2006

### copresh1

I am trying to do a project on electrical engineering which involves design of electrical circuitry for a soot blower arrangement.i am having problems in designing a motor( 3phase induction motor). i know how to calculate the rotor parameters,losses, efficiency,etc. i am told that i have to find the load and load torque on the motor. how do i do that and how i proceed from there?.i would appreciate if anyone can help me in this.

2. Aug 13, 2006

### Andrew Mason

To find the load on the motor (it doesn't matter what kind of motor it is) you need to find the work done per unit time. In this case, it is the work done in blowing soot, I should think. Determine the pitch and speed of the fan and the volume (and mass) of air/soot it moves per rotation. From that you can determine the force x distance / time = power.

To produce that power, you will need to factor in the efficiency of an electric motor, which is typically 75-80%.

The torque of the motor will depend on how it is connected to the load. If it is directly connected (same speed as fan) the torque is related to the fan speed:
$$Power = \tau\omega = 2\pi\tau f$$ where f is the speed in revolutions per unit time

AM

Last edited: Aug 13, 2006
3. Aug 14, 2006

### copresh1

there is no fan invovled here( sorry i shud have mentioned)the cleansing media is steam and directed directly from a steam manifold.how do i go ahead?

4. Aug 14, 2006

### Andrew Mason

You have not told us what the motor does. You have to figure out what work the motor is doing per unit time. If you can describe the set-up we might be able to help you.

AM