Pulsed-width modulation technique for family of (3N+3)-switch converters

This paper proposes a carrier-based pulse-width modulation (CBPWM) scheme for N independent three-phase loads using the general (3N+3)-switch converter. The proposed topology is derived from the nine-switch converter which is gaining considerable interest from researchers because it costs less due to its reduced number of active switches. The structure and limitations of the converter are elaborated; its modulation scheme is formulated in this paper. The generalized neutral voltages for the converter is derived for the first time and used as the offset voltages required by this type of topology to decouple the converter´s N outputs. The proposed algorithm is validated by both theoretical simulation and experimental results using the 9-switch and 12-switch topologies as case studies.