During the last few years the European regulations regarding harmful emissions from vehicles lead to the appearance of alternative propulsion technologies in mass production. Hybrid and electrical driving represent the main solutions used by the vehicles manufacturers to significantly reduce the CO2 emissions or to achieve zero emissions. Nowadays, the battery technology represents the main obstacle in developing the alternative powertrain solutions. The batteries used for the vehicle's powertrain can only store a small quantity of energy, compared to their weight and size, thus they are heavy and take up much space. To maximize the value of this energy and to obtain a maximum autonomy, it is necessary to use electrical motors with higher efficiency.