New Topologies of High Torque Density Machine Based on Magnetic Field Modulation Principle

With the increasing demand for high torque density in motors, more and more new topologies emerge. Furthermore, the magnetic field modulation principle is widely concerned and has evolved into an effective analysis method for studying the new motor topology. This paper introduces the principle of magnetic field modulation. And the research on high torque density in recent years is reviewed from the perspective of magnetic field modulation, including permanent magnet vernier machine (PMVM), flux reverse machine (FRM), flux switching machine (FSM), dual permanent magnet (DPM) machine, and DC biased machine. The principle of magnetic field modulation makes it possible to propose higher torque density topologies in the future.