Switched reluctance machines with simple hoop windings

Switched reluctance machines are usually constructed with coils wrapped around radial poles. The MMF of these coils causes a magnetic flux to flow radially up the poles, returning circumferentially through rotor and stator core backs. As the pole number is increased then the number of coils rises but, due to decreasing space per coil, the MMF per coil falls, so that increasing the pole number does not necessarily increase the torque capability of the machine. This paper presents results from a machine topology which circumnavigates the above problem: the pole number can be increased without reducing the MMF per coil. As the pole number rises the rate of change of permeance of the circuit rises, so that it appears that a high pole number will result in a very high torque machine.