electromagnetic modeling of wound rotor induction motors using conformal mappings

Accurate modeling of slotted air-gap electric machines, which has slots on both sides of air-gap, is the mainproblem which is being addressed in this paper. to this end, conformal mapping (cm) method is presented inthis paper for electromagnetic modeling the wound rotor induction motors (wrim). the cm method canaccurately consider the real pathes of flux tubes in the slotted air-gap by using the calculation of air-gapcomplex permeance. the air-gap complex permeance is really the complex transform function between theslotted air-gap in the physical domain and the slotless air-gap in the canonical domain. in cm method, first ofall, the physical slotless air-gap including equivalent line currents is conformally mapped into the canonicalslotless domain. secondly, the air-gap magnetic field is calculated in canonical slotless domain usinghague’s solution, and mapped back into the physical slotless domain. thirdly, the saturated relative complexpermeance function is used to consider the effects of saturated slotted air-gap on the air-gap magnetic field.in final, the results obtained through cm are well verified by comparing with corresponding results obtainedfrom finite element method (fem) and experiment set-up in terms of accurate prediction of fundamentalcomponent and other harmonic components.