Space-Shifted Split-Phase High-Speed Motor/Converter Topology with Fault-Tolerance Capability

A novel motor/converter system topology is presented, which is ideal for high-power, high-speed motor applications, especially in the case of utilizing permanent magnet synchronous AC motors. The proposed system utilizes space-shifted, split-phase, motor stator configuration, with a modular converter topology. The stator winding configuration allows the harmonic current from the different phases to cancel each other out, while maximizing the fundamental space vector. Hence, the proposed topology does not require the high-frequency PWM normally needed to reduce the time domain harmonics found in the phase currents. The switching frequency of the power converters can actually be as low as the fundamental frequency, which significantly reduces the switching losses, associated EMI mitigation, and cooling challenges. The modularity of the proposed topology also simplifies overall system design and manufacturing, provides redundancy and inherent fault-tolerance. In this paper, the system topology and control strategy are discussed. Simulation and FEA results are presented to illustrate the harmonic cancellation and other advantages of the proposed topology. Experimental results also confirm the validity of the proposed system topology.