In this book, we describe a design methodology of converter with electromagnetic switches, dedicated to the electric traction. The design gait rests on the development of an analytic model providing the manufacturing data's of this converter. This gait of design take in account the adaptation of this converter, characterized by a low switching frequency to the global system, while inserting a reducer characterized by a ratio calculated by a manner guaranteeing to the electric vehicle to reach the maximal speed (100 km/h), and to have a good dynamic characteristic.