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