Table of Contents
D. Muller, F. Thollon
Centre de Genie Electrique de Lyon
Ecole Centrale de Lyon
Other applications or tools from this site:
mWave,
Edgar
To the list of Colos applications
mField (named chamTou in french) is an application intended to show how one can generate a rotating field inside of a rotating electrical machine.
In a first step one may discover that a single wire is only able to generate a pulsing field (not a rotating one) if fed with sinusoidal current.
The second step consists in generating a rotating field using two wires fed with sinusoidal currents with different phases, and finally one may generate a rotating field with three wires which corresponds to industrial reality.
The mField package solves well-known analytical equations in real time to provide instant feedback to user interactions and animation effects.
mField is intended to be used to allow students to visualize the magnetic field inside the machine air gap, and to intuitively understand how to generate a rotating field by supplying at least two sinusoidal currents with appropriate phases. This last step may be achieved by freely trying any possible phase values until obtaining the desired effect.
Three different representations of the field value are provided on three different abstraction levels:
- coloured pixels,
- sine wave displayed along the air gap, and
- vectors directed to the field maximum .
mField is intended to be used to show "how the real world is" before having to introduce any theoretical approach. Showing the equations, explaining the principle of superposition, etc... should come later.
This package is written in C and the user interface conforms to industrial standards X-Window (X11R5) and Motif (1.2) which guarantees easy porting to most Unix platforms.
The user interface is deliberately made simple to allow easy access for users who are unfamiliar with computer use. All highly interactive actions may be taken using activators (thumb wheels) on the front panel, whereas configuration modifications are done using the menu tree accessible from a standard menu bar.
This module is intended to be used by a teacher to demonstrate the rotating field generation, followed by a "trial and error" session where students may test their own way of thinking.
The only needed background for the user is to know what a sine wave is, and to understand the classical value versus time curve representation. In the domain of electricity, the user should have heard about electro-magnets.
This software is in the process of being evaluated by professionals in the domain of didactics, and will be tested by some tens of secondary school teachers, and up to 300 high school students.