A distributed anisotropy linear reluctance motor

The behaviour of a distributed anisotropy linear reluctance motor is investigated, from the viewpoint of its magnetic characteristics, d-q parameters, thrust production and cross d-q axis coupling due to saturation phenomena. It is shown that, accounting for quadrature air gap induction, the mathematical model of the linear reluctance motor cannot be immediately deduced from that of the rotating motor, as is the case of the induction motor. Therefore a dedicated mathematical modelling of the linear anisotropic structure is presented. The air gap inductance versus relative position is determined by solving a system of differential equations with variable coefficients. The reluctance thrust is then evaluated, taking into account the static end effects. The coupling between d and q-axis reactances, due to saturation phenomena, is numerically evaluated. Finally, the test results of a four pole prototype motor are presented.