Induction motor analysis
QuickField simulation example
This is a simulation example from Compumag TEAM Workshop Problem 30*.
Engineering question
How to find TEAM induction motor benchmark problem
Engineering answer
Set up a plane-parallel QuickField AC Magnetics problem for an induction motor benchmark model and evaluate performance characteristics from computed field results.
Typical applications
TEAM benchmark induction motors, rotating field motors, induction motor test cases
- Download simulation files (files may be viewed using any QuickField Edition).
Problem Type
Plane-parallel problem of AC magnetics.
Geometry
Given
Current density in a coil j = 310 A/cm² (r.m.s)
Frequency f = 60 Hz.
Aluminum conductivity 37.2 MS/m.
Relative permeability of steel μr=30.
Rotor steel conductivity 1.6 MS/m.
Stator steel is laminated and has a zero conductivity.
Task
Calculate the torque, rotor steel and aluminum Joule heat losses and compare the results with a reference value.
Solution
To simulate the motion we will attenuate the AC problem frequency: fslip = slip * f,
where slip = 1 - (rotor angular frequency / synchronous angular frequency).
Synchronous angular frequency is 2πf = 2*3.142*60 = 377 rad/s.
| Rotor angular frequency, rad/s | Slip | Frequency fslip, Hz |
|---|---|---|
| 0 | 1 | 60 |
| 200 | 0.469 | 28.2 |
| 400 | -0.061 | -3.66 |
| 600 | -0.592 | -35.5 |
| 800 | -1.122 | -67.3 |
| 1000 | -1.653 | -99.2 |
| 1200 | -2.183 | -131 |
It is not possible to specify the negative frequency in the problem. Instead we specify |fslip|, but consider the calculated torque value to be negative.
Results
Eddy current distribution at 28.2 Hz (equivalent to rotor angular frequency of 200 rad/s). Torque is 6 N*m, rotor steel losses are 15.7 W, rotor aluminum losses are 1061 W.
Reference
*Compumag TEAM Workshop
- Download simulation files (files may be viewed using any QuickField Edition).