The interest of the electric vehicle is increasing due to new models in the market with long ranges. Both users and auto makers agree in the electrification of vehicles. Most of the auto makers have at least one electric model in the market, indeed. Some of these auto makers only produce these type of vehicles, which have made up a high impact, such as Tesla. Nevertheless, users’ major concerns are the range anxiety, charging time and charging station infraestructure.

In order to overcome these issues, a review of main elements in an electric vehicle has been done, studying energy sources, charging systems, motor technologies, and power converters. Although the efficiency of the electric vehicle is superior to other type of vehicles, the capacity of the battery is the major issue, pointing out the efforts of researches in enhancing the range.

A review of power converters of electric motor propulsion is also analyzed in terms of switching devices, their encapsulation, inverter topologies, their cooling systems and their control. In order to enhance the life-cycle of these elements, the stress has to be minimized, being the reliability of the vehicle one of the most important aspects to be considered.

Since the thermal stress source is the most important factor for the devices, beside the correct operation of the cooling system, is desirable to decrease power losses. In this thesis, various modulation techniques have been studied to reduce losses in devices.

Many modulation techniques have been developed in order to use in motor propulsion. The main goal of some of these strategies is to reduce switching losses of devices, so the main target of this study has been the switching loss reduction.

The first contribution of this thesis has been developed using a discontinuous modulation technique. With these techniques, one of the phases is clamped to the upper or lower DC link during a fraction of a period in order to avoid switching instants in that phase. An optimal modulation waveform has been implemented, which minimizes switching losses, and the current of the inverter’s input has been analyzed. This analysis follows the study of DC bus capacitor’s losses, and the development of a modulation strategy which minimizes both swithcing losses and DC-link capacitor’s losses.

The second contribution has been achieved not varying the modulation waveform, but the period of the carrier wave. This period has been calculated according to the optimization process of minimizing switching losses and maintaining output currents quality.

Both techniques have been tested in simulation and experimental data in order to compare with the conventional SVPWM technique. Moreover, a NEDC have been simulated for both techniques, in order to compare the results.