(SRG) A SRG differs from conventional machines in that it does not have any windings or permanent magnets on the rotor. The stator typically consists of slots containing a series of coil windings, the energisation of which is electronically switched to generate a moving field. The reluctivity of the rotor results in a torque which tends to move the rotor in line with the energising coils, minimising the flux path. For an SRG, mechanical energy is converted to electrical energy by the proper synchronisation of stator phase currents with rotor position. By appropriate control of stator switching it is possible to achieve variable speed operation for the generator.