{Development and demonstration of a medium-voltage high-power DC-DC converter for DC distribution systems}

Title{Development and demonstration of a medium-voltage high-power DC-DC converter for DC distribution systems}
Publication TypeConference Paper
Year of Publication2014
AuthorsSoltau N, Stagge H, De Doncker RW, Apeldoorn O
Conference Name2014 IEEE 5th International Symposium on Power Electronics for Distributed Generation Systems (PEDG)
ISBN Number978-1-4799-5115-4
KeywordsBridge circuits, DAB1, DAB3, DC-DC power converters, inductance, Insulated gate bipolar transistors, Medium voltage, power distribution, power grid, Power transmission, snubbers, Switches
AbstractIn 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.