Shaping and dimensioning of the flux barriers in synchronous reluctance machines

Due to the high efficiency at the rated point and at partial load, the interest in synchronous reluctance machines grows steadily. A particular difficulty is the design of the flux barriers in the rotor. A simple approach to determine the shape of these barriers is to replicate the magnetic field lines in an isotropic rotor. For this purpose, a magnetostatic model is created and calculated analytically. This barrier shape is combined with known sizing methods to obtain a straightforward design procedure. Different sizing methods are compared with numerical simulations (2D-FEM software) in order to analyze the influence on the design procedure. Therefore, a time-efficient simulation method is used to evaluate the rotor design procedures. It is shown that the different methods yield similar results and an optimal solution always depends on the considered case, so that an optimal sizing method cannot be deduced.