Modular 2n-phase Inverter (M2I) Topology with Novel Phase Current Injection Scheme for Fault-tolerant Multiphase Electric Machine Drives

This paper proposes a new modular 2n-phase inverter (M2I) topology for fault-tolerant multiphase electric machine drives. The proposed M2I topology consists of multiple two-phase inverters, which provide individual phase current controllability for phase redundancy in case of phase-leg open-circuit failures. Each two-phase inverter module can also independently produce constant instantaneous output torque for parallel redundancy in case of inverter module failures. This paper also introduces a novel phase current injection scheme for two-phase inverter operation. The proposed scheme overcomes one of the main drawbacks of the conventional two-phase inverter, which is 40% higher amplitude of neutral current than that of phase current. The design and operating principle of the proposed M2I are introduced, and the improved fault-tolerant operation capability is verified with simulation.