One of the recurring problems facing propulsion systems, which are currently being extensively researched, is the issue of common-mode voltage (CMV). This voltage produces serious problems in motors driven by power converters that are controlled with pulse-width modulation (PWM)-based strategies. Specifically, the switching patterns of the power devices produce unbalanced voltage waveforms that oscillate at high frequencies, thus causing a CMV waveform that is harmful to the propulsion system. Among the main problems that derive from this voltage are the leakage currents that circulate through the bearings, the deterioration of the insulation of the stator winding, and electromagnetic interferences. All of these problems, taken together, can lead to poor motor performance or even complete powertrain failure. Moreover, if an adequate solution is not found, these problems will become more frequent in the next few years. Nowadays, electric vehicle manufacturers are beginning to develop new solutions based on battery packs that operate at higher voltages, i.e. 800 V, instead of the traditional 400 V systems. In addition, the need to improve propulsion systems (in terms of power density, efficiency, dynamic response, etc.) makes it necessary to increase the operational speed of electric motors. However, an increase in speed requires power converters that switch at higher frequencies. For this reason, manufacturers are resorting to wide-bandgap power semiconductors that allow switching at higher operating frequencies. The drawback is that an increase in battery voltage or an increase in the switching frequency of power semiconductors can aggravate the waveforms of the CMV and, therefore, worsen the issues derived from this highly problematic voltage. Considering the above, in this doctoral thesis, a new power converter is proposed and analyzed in detail together with a new modulation strategy. This converter seeks, on the one hand, the reduction of the CMV and, on the other hand, that the rest of the benefits of the on-board propulsion systems in current electric vehicles are not hindered. Specifically, as the trend followed by manufacturers, in regard to the power converter, is still to use the two-level three-phase inverter, commonly known as voltage-source inverter (VSI), in this thesis a new variant of this inverter, called ZVR-D2, has been proposed. This inverter consists of two diode rectifier bridges to decouple the converter from the motor when the modulation technique uses zero voltage vectors. At the same time, clamping diodes are used to provide the electric motor with the desired CMV value, thus reducing this undesired voltage. The approach followed to develop this doctoral thesis has been, in the first place, conduct an exhaustive review of the state of the technology, both of the problems derived from the CMV and of its main solutions. In addition, It has been reviewed the existing alternative converter topologies and modulation techniques to reduce this voltage. Secondly, and to evaluate the performance of the proposed ZVR-D2 converter, several simulations have been carried out that allow, on the one hand, to analyze its performance in detail and, on the other hand, to compare it with other existing solutions that have been previously proposed by other authors. Finally, an automotive-scale inverter prototype has been developed to experimentally validate the concept of CMV reduction over the proposed converter topology. From the results obtained, the high performance of the proposed solution is demonstrated in comparison with the conventional VSI, bringing about a significant CMV reduction and, at the same time, finding a balance between the remaining features of the power converter. It is shown that a reduction of the CMV leads to a slight worsening of other parameters, such as the converter efficiency or the harmonic distortion of the current delivered to the motor. However, it is shown that, depending on the modulation strategy, it is possible to adjust the improvement or deterioration of all these features, even operates using only the conventional VSI, if desired. In fact, migrating from the conventional VSI to the new ZVR-D2 converter is simple and can be beneficial as additional degrees of freedom can be exploited to solve major reliability problems in today's powertrains.