# Animation: Operating principle of a 3-phase alternator

The top left-hand section of the animation shows a cross-section of a 3-phase alternator. The alternator has 3 windings, which are shown in 3 different colours.

The level of the currently induced voltage can be described by three formulae, which are shown in the top right-hand section:

These formulae describe the sinusoidal induction voltages as a function of time t for each of the 3 windings. The phase shift of 120 degrees can be explained by the arrangement of the induction coils, which are rotated by 120 degrees to each other. Û (U with circumflex) stands for the maximum voltage (amplitude). The symbol ω (omega) represents the angular frequency.

The maximum voltage Û can be calculated using the following formula:

• Û is the maximum voltage (amplitude) of the induced alternating voltage.
• k is a proportionality constant that depends on the specific properties of the generator.
• B is the field strength of the excitation magnet.
• A is the effective area of the conductor cross-sections through which the magnetic field passes.
• n is the speed of the generator

The factors B and n can be influenced in the animation via two virtual controllers. The lower section shows the voltage curve and the pointer diagram (complex number plane).

## Note on use

After starting the application, you can view the animation in full-screen mode. To do this, click on “View” and then on “Full screen”:

To exit full screen mode, press the Esc key.