In this applet one of the sinusoidal sources has now been replaced by a three phase rectangular voltage source. The rectangular voltage can be represented as a space vector with 6 distinct positions on the vector diagram. Compare this to the sinusoidal source that produces a continuous circle on the vector diagram. The 6 vectors produced by the rectangular source are labelled with 3 numbers in parentheses (xxx), with each number being either a ‘1’ or a ‘0’ to represent the polarity of the phase voltage. A ‘1’ represents when the phase voltage is positive and a ‘0’ when the phase voltage is negative. Each of the three numbers represent one of the phases. For example, (110) means that the voltages of phases R and S are both positive and that phase T has a negative voltage. By moving the ‘red timeline’, each of the rectangular vectors and the phase voltages can be viewed.

The voltage that appears across inductor is now dependent on the rectangular voltage and sinusoidal voltage. The rectangular voltage waveform and vector stays constant for 60 degrees before changing to a new value while the sinusoidal voltage vector continuously rotates. This causes a non-sinusoidal current to flow in the inductor and this can be easily seen as the current vector does not now follow a circular track. Interesting shaped current vector patterns can be made by changing the magnitude and phase angle of the sinusoidal source. A sharp point appearing in the current vector track means that current waveform has a discontinuity in it, as can be seen in the time plots.

• Move the red timeline to view the 6 discrete rectangular voltage vectors.
• Adjust the magnitude and phase angle of the sinusoidal source by moving the red arrow head and view the change in the current waveform and vector track. 
• Adjust the inductor value and observe the change in the current waveform and vector track.