Electromobility has been growing rapidly in recent years, as a result of green and sustainability policies that promote it, but its growth has been hampered by having less autonomy than combustion vehicles, not being able to directly replace them especially in heavy-duty electric vehicles powertrains. The main objective of this work is to propose an improvement to an already implemented Bidirectional Dual-Active-Bridge (DAB) Partial Power Converter (PPC) topology, seeking to boost efficiency by testing different modulations. The modulation study applied to PPC is interesting in order to identify the cases where the RMS current in the transformer is minimized. Results of the study shows that efficiency of the DAB-based PPC can be optimized by using the correct modulation, with a possible maximum efficiency of 99.41% at 6.526 kW.

In conventional EV powertrains the main energy storage system is based on battery banks. Potential higher current stress on battery during transient operation can considerably reduce its expected lifetime, while battery size is overrated to respond under heavy transient demands. The regenerative braking capability is also getting limited due to its charging dynamic constraints. Hybrid Energy Storage Systems (HESS) based on batteries and supercapacitors (SC) have the potential to solve this issue. However, SCs size and weight can deteriorate the power density of the solution. In this paper, a Partial Power Configuration (PPC) based on Dual-Active-Bridge (DAB) is proposed as a power interface to increase the power density of an HESS-based EV powertrain. A comprehensive efficiency analysis is provided, while transient dynamic results are provided to validate the proposed power configuration.

This paper presents a grid-connected seven-level cascaded H-bridge converter operating as photovoltaic inverter. The main issue with this topology are the natural power imbalances between the power cells and the phases of the converter. The control problem is addressed with a Multiobjective Finite Control Set Model Predictive Control, where a dc-link voltage balance among the cells and good tracking of the active and reactive power references injected to the grid are achieved. Furthermore, an average switching frequency control per cell has been included. The proposed control scheme is validated trough simulation results and tested under dynamic conditions.

This investigation presents a grid-connected five-level H-bridge neutral-point-clamped converter operating with a single dc-link as photovoltaic power source. The operation with a single dc-bus is enabled by adding a transformer with open-end winding secondary, where each power cell of the converter is connected. The proposed control scheme is validated trough simulation results and tested under dynamic conditions. It can be implemented with a good tracking of the active and reactive power references injected to the grid. The results serve as a preliminary validation to potential utilization of the converter in large scale photovoltaic energy conversion systems.