BLDC multiphase reluctance machines for wide range applications: A revival attempt

In an yet another effort to produce better PM-less rotor-winding-less, brushless electric motor drives, the present paper reports on preliminary work related to multiphase (m=6, 7, 9) high saliency rotor, dual-flat-top alternative current control BLDC reluctance machine drives. The aim is to produce high torque density, low loss / torque in a PM-less, rotor winding-less machine by full usage of machine windings and core and of inverter kVA (higher equivalent power factor). And all these for wide spectrum uses, from automotive electric propulsion to wind energy conversion and to passive guideway MAGLEVs (for the linear version of the machine). We practically revive and expand a concept introduced by Weh in 1986 and followed by Boldea in 1990 and Lipo in 1992. A new derivation of the principle of operation, essential rotary and linear machine topologies with generic pertinent control and a 2-D FEM analysis for torque density, loss / torque and torque pulsations on an already built (6 phase, 6 poles) - 40 Nm lab prototype and for a 6 MW, 12 rpm hypothetical wind generator, are made available and show promising results. Experiments on the already built lab model are due in the near future.