Space vector vs. sinusoidal carrier-based pulse width modulation for a seven-phase voltage source inverter

The paper presents an extensive comparison between two pulse width modulation (PWM) control schemes, namely carrier-based and space vector based PWM for a seven-phase voltage source inverter. Sinusoidal carrier-based PWM and space vector PWM techniques are employed to control multiphase power converters supplying variable speed multiphase motor drive systems. Implicit relationships that exist between the two PWM techniques are comprehensively explored; this paper, reveal the underlying relationship between the two PWM techniques in terms of several parameters such as modulating signals and space voltage vectors, modulating signals and space voltage vector sectors, switching pattern of space vector and type of carrier. Furthermore, sharing of zero vectors among different chosen space vectors is elaborated that leads to the formulation of different types of modulation. Digital implementation of the two modulation schemes is elaborated. Simulation results are validated using experimental investigation.