This paper presents the three phase dual active bridge topology as the most convenient topology for high-power-density DC/DC converters for railway applications. The desired DC/DC converter has a nominal input voltage of 750V, with a range of 500V to 900V, and should provide a regulated 600V output voltage. In the entire range, 80kW of continuously output power is required. To these specifications, the three phase DAB is analyzed concerning the current modes, output power and softswitching region, including the effect of zero voltage switching capacitors. Furthermore, two methods are discussed, aiming to extend the soft-switching region, since no-load conditions in the entire operating range are required. These methods compromise the use of auxiliary inductors and a straightforward switching strategy. A prototype design is made, where optimal component values are determined, based on minimizing losses. Finally, a prototype is build with the required specifications, resulting in an efficiency of 95.6% at 80kW of output power.
|Date of Award
|31 Aug 2013
|Jorge L. Duarte (Supervisor 1), Wim Platschorre (External coach) & Jaap Verschoor (External coach)