This article proposes a methodology for an adequate design of a 3-levels flux barriers rotor of a synchronous reluctance machine (SR), in order to obtain the highest performances. For that, this study seeks to determine the optimal shape of the flux barriers and at the same time the best current supply of the stator windings. The methodology applied consists in a double optimization: the search for the best rotor geometry and the determination of the best suited electrical control. This approach is applied on 3 types of rotor architecture: the classic SR, the (ferrite) permanent magnet assisted SR and the Dual Phase rotor SR. The design of flux barriers-SR is a very intricate problem, because many variables (geometric and electric) are involved and in addition, the physical aspects appearing in this kind of structure are strongly nonlinear, so that physical quantities have to be evaluated by means of Finite Element Analyses.