In this applet a six-switch inverter is switched at low frequency to generate square-wave voltage outputs. The switching frequency is same as the required fundamental frequency. This is not high frequency switching that is typically expected from a six-switch PWM inverter, however the advantage of square-wave switching is that the switching losses are very low. Since the output inverter voltage is a square-wave the load current is also non-sinusoidal. 

The phase voltage generated between an inverter phase output and the load star point is a multi-stepped waveform. This is because there is a square voltage waveform generated between the load star point and the inverter midpoint voltage and this square waveform has a frequency that is 3 times the fundamental output frequency.

• Change the amplitude and phase angle of the load voltage source. This changes the load current waveform shape and amplitude.
• By moving the red time line the current flow in the inverter switches can be observed as well as the movement of the current vector.