Eindhoven University of Technology

Advantages of low voltage DC grids compared to AC supplies are lower losses, higher system efficiency because of less conversion steps, no effort and loss of efficiency for management and compensation of reactive power, capability to transmit higher power through the same cable, easier buffering of peak load by batteries, smaller appliances, lower cost of appliances and systems. To demonstrate some of these advantages, the TU/e is developing in the frame of DCSmart an isolated bidirectional DC/DC converter for interfacing local loads (electrified vehicles) or local storage applications. The converter under development comprises an internal high-frequency isolation transformer, aiming at current stress optimization and zero-voltage switching operation. On this basis, the optimized modulation scheme leads to the minimum current stress with the required transmission power and voltage conversion ratio in the whole load range. Moreover, the intention is to apply a multilevel topology in order to allow using standard 600V semiconductor switching devices operating from the 800Vdc grid.