Spectrum Software
Industrial Strength Simulation




Spectrum Software has released Micro-Cap 11, the eleventh generation of our SPICE circuit simulator.

For users of previous Micro-Cap versions, check out the new features available in the latest version. For those of you who are new to Micro-Cap, take our features tour to see what Micro-Cap has to offer.




AC Induction Motor Model


Here is a new AC induction motor model for Micro-Cap. It is based on a model created by Sohor and Kubov. For more information, see http://valvolodin.narod.ru/articles/Induction3phMotor1. pdf. The signs of BX and BY have been reversed from those in the article.

Here is what the motor model looks like:

AC Induction Motor Model

The model provides three pins for the input AC drive: A, B, and C. It provides three pins for output: Velocity, Torque, and RPM. The load is attached separately between the Velocity node and ground.

Three types of load are provided: no load, viscous friction, and square law friction. Each of these load types may be attached to the Velocity pin to see how the motor responds. The model currently has no provision for eddy current losses.

The next figure shows a typical test setup.

AC Motor Test Circuit

The next figure shows the motor armature current, torque, and RPM waveforms for the Torque0 (no load) condition.

AC Motor waveforms for no load

Here are the response waveforms for the Torque1 (viscous friction) and Torque2 (square law friction) load conditions.

AC Motor waveforms for viscous friction

AC Motor waveforms for square law friction

Download Spring 2014 Circuit Files
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