An Overmodulation Technique for Asymmetrical Six-Phase Voltage Source Inverters With Low Voltage Harmonic Injection

This paper introduces a novel overmodulation strategy for two-level six-phase voltage source inverters based on a dual three-phase model. The architecture is an extension of a modulator recently presented in the literature. The algorithm is based on a generalised solution of the duty cycles, and a preprocessor is added to modify the target voltage appropriately to compensate the synthesised voltage. The redesigned architecture can generate voltage beyond the linear region with a low injection of undesired harmonic components in the inverter output. Simulations and experimental tests are carried out to validate the theoretical results. The performance achieved with this proposal is compared respect to a minimal distortion method, and a slightly lower voltage harmonic content is obtained.