11251

Characteristics of Three-Phase Asynchronous Motors

This Demonstration shows a series of curves for rotation rate versus electromagnetic torque for a three-phase asynchronous motor. By adjusting the parameters of the asynchronous motor, you can observe the effects of the parameters interactively. The parameters are defined in the Details.
Three-phase power systems have phases of equal amplitude, shifted by 120˚. Since the phases are similar, the easiest way to analyze a three-phase circuit makes use of a per-phase equivalent circuit.

DETAILS

Snapshot 1: only into 200 V,
Snapshot 2: only from 2 to 3.16 , becomes greater, but still remains unchanged
Snapshot 3: only into 3,
Figure 1. The per-phase stator and rotor circuits as rotating of asynchronous motor.
An asynchronous motor is also called an induction motor. Here are the definitions of the parameters.
: voltage of stator
: current of stator windings
: current of rotor windings
: electromotive force of stator windings
: electromotive force of rotor windings
: number of stator windings
: number of rotor windings
: stator winding factor
: rotor winding factor
: resistance of stator windings
: resistance of rotor windings

: frequency of power grid (Hz)
: synchronous rotation rate of three-phase asynchronous motor (RPM)
: rotation rate of three-phase asynchronous motor (RPM)
: slip ratio
: stator phases leakage reactance
: rotor phases leakage reactance as rotor rotating

: rotor phases leakage reactance
: number of stator phases
: number of rotor phases
Figure 2. The per-phase stator and rotor circuits after referring of frequency.
Figure 3. The per-phase stator and rotor circuits after referring of windings.
Figure 4. The per-phase equivalent circuit of an induction motor.
Figure 5. The resulting simplified equivalent circuit of an induction motor.

: synchronous angular velocity of three-phase asynchronous motor (rad/s)
: air-gap power
: synchronous rotation rate of three-phase asynchronous motor (RPM)
: rotation rate of three-phase asynchronous motor (RPM)
: slip ratio
: rated slip ratio
: critical slip ratio
: electromagnetic torque (Nm)
: starting electromagnetic torque (Nm)
: rated electromagnetic torque (Nm)
: maximum electromagnetic torque (Nm)
: RMS voltage of stator phases (V)
: number of stator phases,
: number of asynchronous motor pole pairs
: frequency of power grid (Hz)
: stator phases resistance ()
: rotor phases resistance referring to the stator side ()
: rotor phases current referring to the stator side (A)
: stator phases leakage reactance ()
: rotor phases leakage reactance referring to the stator side ()
Equations, principles, and figures referenced from [1].
References
[1] Xu-Xiaofen, Electric Motor and Drive [M], (in Chinese), Beijing, China: Higher Education Press, 2007.
[2] S. J. Chapman, Electric Machinery Fundamentals, 4th ed., New York: McGraw–Hill, 2005.

PERMANENT CITATION

 Share: Embed Interactive Demonstration New! Just copy and paste this snippet of JavaScript code into your website or blog to put the live Demonstration on your site. More details » Download Demonstration as CDF » Download Author Code »(preview ») Files require Wolfram CDF Player or Mathematica.

Related Topics

 RELATED RESOURCES
 The #1 tool for creating Demonstrations and anything technical. Explore anything with the first computational knowledge engine. The web's most extensive mathematics resource. An app for every course—right in the palm of your hand. Read our views on math,science, and technology. The format that makes Demonstrations (and any information) easy to share and interact with. Programs & resources for educators, schools & students. Join the initiative for modernizing math education. Walk through homework problems one step at a time, with hints to help along the way. Unlimited random practice problems and answers with built-in step-by-step solutions. Practice online or make a printable study sheet. Knowledge-based programming for everyone.
 © 2017 Wolfram Demonstrations Project & Contributors  |  Terms of Use  |  Privacy Policy  |  RSS
 Note: To run this Demonstration you need Mathematica 7+ or the free Mathematica Player 7EX Download or upgrade to Mathematica Player 7EX I already have Mathematica Player or Mathematica 7+