3-dimensional finite element analysis of a bridged rotor switched reluctance motor

The switched reluctance motor is eminently suitable for submersible pump deep well applications because of its inherent variable speed operation and its robust mechanical construction. The salient construction of the rotor does not, however, lend itself for use in a wet rotor motor design. To ensure that the rotor has an appropriate mechanical form, steps must be taken during manufacturing to ensure that the rotor surface is smooth and cylindrical. One method of achieving this is to use a rotor which incorporates interpolar bridges. With this type of rotor construction, a thin strip of lamination material that spans the gap between adjacent rotor poles is left in place during the manufacture of the lamination. A two dimensional cross-section of the bridged rotor construction is shown. This paper describes a 3D finite element study carried out to make a preliminary assessment of this form of rotor design.