Modular Torque Control of Multi-Three-Phase Synchronous Motor Drives

Multiphase motors offer more degrees of freedom when compared to their three-phase counterparts. Their intrinsic redundant structure enables the post-fault operation of the drive, thus preventing inoperability. Additionally, more advantages are obtained when a modular drive topology is adopted in machine windings and power converters. This is particularly convenient, especially when three-phase technology can be adopted, resulting in a multi-three-phase drive configuration. However, modular torque control strategies are needed to fully exploit the advantages provided by the multi-three-phase configuration. Therefore, an innovative control scheme implementing modular torque regulation of multi three-phase synchronous motor is proposed in this paper. The stator flux amplitude and the torque-producing current component corresponding to each three-phase set are independently controlled to perform the decoupled torque regulation. Experimental results on a 60 kW quadruple three-phase interior permanent magnet (IPM) synchronous motor are provided to prove the effectiveness of the proposed torque control solution.