Pablo Frack und Nils Soltau visit the PEDG Conference in Galway and presenting their papers

26/06/2014

Pablo Frack und Nils Soltau visit the Power Electronics for Distributed Generation PEDG 2014 Conference in Galway present their papers "Control-Strategy Design for Frequency Control in Autonomous Smart Microgrids" and "Development and Demonstration of a Medium-Voltage High-Power DC-DC Converter for DC Distribution Systems".

  Pablo Frack is presenting his paper in PEDG 2014  

Abstract

Control-Strategy Design for Frequency Control in Autonomous Smart Microgrids

Microgrids (MGs) are expected to have low inertia, making a MG a more dynamic grid than a conventional one. Among the consequences, the impact on protection systems due to the rapid variations in power demand or generation is one of the most important. This paper proposes a control strategy for frequency control in isolated MG with the aim of improving its dynamics. Especial focus is done on the positive impact on Rate of Change of Frequency- (RoCoF-) relays.

Development and Demonstration of a Medium-Voltage High-Power DC-DC Converter for DC Distribution Systems

In many low-voltage or high-voltage applications, the electrical energy transmission and distribution is enhanced using direct current (dc) already today. To use the advantages of dc also in medium-voltage applications a highly efficient dc-dc converter is needed that has a power capability of several megawatts. At the E.ON Energy Research Center of the RWTH Aachen University a demonstrator for a 5 MW medium-voltage dc-dc converter is constructed, which is presented in this work. Firstly, some general considerations about the three-phase dual-active bridge dc-dc converter are made, with a focus on medium-voltage high-power applications. Whether IGBTs or IGCTs are the optimal switching devices is discussed and a further improvement using a Dual-ICT is evaluated. The construction and the design of the mentioned demonstrator are presented. Besides the demonstrator itself, the medium-voltage high-power transformer that is operated in the ac link is discussed in detail. Finally, the advantages of a three-phase dual-active bridge over the single-phase variant are discussed using the experience gained from the commissioning.