Contents I. Introduction
In recent years, multiphase drives have become attractive solutions in systems where reliability is a fundamental requirement for guaranteeing the safety of the people or the continuity of the operating conditions. The applications that take more advantage of multiphase technology are the aerospace, naval, and powertrain ones [1]–[3]. The multiphase technology allows splitting the output power among more than three phases. This peculiarity reduces the size of the components used in the power converters. This characteristic is appreciated in high-power applications where the technical limits of the commercial power switches impose a strong design constraint, e.g., wind turbine generators. Another important feature introduced by multiphase technology is the increased number of degrees of freedom of the system. The available degrees of freedom can be used to improve the fault tolerance [4]–[6] or increase the torque density of the electric machines [6]. The multilevel topology, combined with the multiphase one, is an interesting technology for further increasing the power density of electric drives and their performance [7]. The multilevel systems enable the quality of the output voltages to increase and simultaneously reduce the voltage stress of the components. As the number of levels rises, the complexity and cost of the converters increase.
