A novel 3-phase SPWM technique: instantaneously floating the neutral point

On the basis of discussion of harmonic injection SPWM (HI-SPWM) and voltage space vector PWM (VSV-PWM), a novel SPWM technique (IF-SPWM), which is really simplest and well designed to obtain maximum inverter gain, minimum switching frequency and to avoid the disadvantages of HI-SPWM, is proposed. The IF-SPWM is based on instantaneously floating the equivalent neutral point of the output of a 3-phase inverter i.e. instantaneously injecting the same voltage waveform into the phase voltages. The validity of IF-SPWM has been proved by simulations and experiments.