Generalized theory of mixed pole machines with a general rotor configuration

This paper introduces a generalized theory for the operation of mixed pole machines (MPMs). The MPM has two stator windings, namely the main winding with pole pairs P₁ and the control winding with pole pairs P₂. The MPM has shown promise in the field of adjustable speed drives for large machines and in the field of wind energy electrical generation. The operation of MPM relies on the interaction between the two fields produced by the two stator windings through the intermediate action of a specially designed rotor (nested-cage or reluctance rotor). The machine theory is described from a physical aspect rather than mathematical derivations. A simple representation is also presented, from which the machine d-q model can be readily deduced. The effect of mechanical loading on the relative positions of the machine fields is also presented.