Modular and Self-Decoupled Torque Control of Multi-Three-Phase Synchronous Motor Drives

The drives adopting multiphase machines can exploit their degrees of freedom to increase performance in terms of fault tolerance and reliability. Indeed, the fault-tolerant operation is intrinsic to the multiphase motor thanks to its redundant structure and prevents inoperability. However, drive control strategies with a modular configuration are required but they typically introduce unwanted couplings that affect the control effectiveness and even its stability if not properly compensated. Therefore, an innovative control scheme implementing modular and decoupled torque regulation is proposed in this paper. The novelty of this work is to independently control the stator flux amplitude and the load angle for each three-phase stator unit. For the first time in the literature, the proposed approach guarantees a true self-decoupled and modular torque control of a multiphase machine, without any additional decoupling action. 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.