Name: Jordi Everts


KU Leuven

Promotor / Supervisor

Prof. dr. ir. Johan Driesen 

Samenvatting van het onderzoek / Summary of Research

Single-phase, utility interfaced, isolated AC-DC converters with power factor correction cover a wide range of applications such as chargers for plug-in hybrid electric vehicles and battery electric vehicles, inverters for multiple renewable energy sources (e.g. photovoltaic modules), as well as interfaces for residential DC distribution systems and energy storage systems. Thereby, bidirectional conversion capability enables the development of smart interactive power networks in which the energy systems play an active role in providing different types of support to thegrid. Examples are vehicle-to-grid concepts, ‘smart home’ concepts, AC microgrids, and residential DC distribution systems (DC nanogrids). 

In the presented work, the main objective is to investigate thefeasibility and suitability of a single-stage (1-S) dual active bridge (DAB) AC-DC converter for the realization of the above mentioned bidirectional energy conversions. Compared to the commonly used dual-stage (2-S) systems, the 1-S architecture has the potential to benefit the system performance with regard to efficiency, volume (power density), number ofcomponents (reliability), weight, and costs, due to the effective omission of a complete energy conversion stage. In order to validate the presented analyses, a second objective is to realize a state-of-the-art (i.e. regarding efficiency and power density) converter prototype system that is designed in order to meet the requirements for future, mode 1 compatible, on-board electric vehicle battery chargers, interfacing a 400 V DC-bus with the single-phase 230 VAC / 50 Hz mains. Compliance with domestic power sockets results in a nominal (active) AC charging current of 16 Arms and a nominal power of 3.7 kW. 

The main challenge toachieve the above objectives lies in addressing the fundamental limitations of the existing analyses and circuit implementations of DAB converters. These limitations mainly relate to the soft-switching (i.e. by virtue of zero voltage switching, ZVS) modulation schemes available in literature, being especially problematic for DAB converters with large input and/or output voltage variations and large power variations, such as is the case for the 1-S DAB AC-DC architecture at hand.

Volledige tekst van het doctoraat / full text

Examencommissie / Board of examiners

  •   Prof. dr. ir. Johan Driesen (promotor)
  •   Prof. dr. ir. Joseph Vandewalle (voorzitter/chairman)
  •   Prof. dr. ir. Dominique Schreurs (secretaris/secretary)
  •   Prof. dr. ir. Jan Genoe
  •   Prof. dr. ir. Geert Deconinck
  •   Prof. dr. ir. Jozef Poortmans
  •   Prof. dr. Johann Walter Kolar , ETH Zürich
  •   Dr. Jeroen Van den Keybus , Triphase NV