Fraunhofer-Institut für Integrierte Systeme und Bauelementetechnologie IISBWe develop all kinds of insulating DC-DC converters for mobile applications. This includes e.g. insulating high voltage (up to 850 V) to low voltage (commonly 14 V, 24 V or 48 V) converters in the power range from 10 W up to approx. 5 kW. With efficiencies of up to 97% and power densities up to 10 kW/dm³, they can be easily integrated into a small car, directly inside the high voltage battery system or the drive inverter. The photo to the right gives a closer look at how by using modern power devices, fully digital control techniques, and mechatronic approaches, outstanding power densities and efficiencies are reached.
As with other Fraunhofer IISB vehicle electronics prototypes, insulating DC-DC converters can be developed for plug-and-play installation.
As an example of a fully housed, insulated 5 kW DC-DC converter with automotive qualified connectors shows. It could be used within two different voltage ranges for applications in light or heavy trucks and can be controlled via CAN interface. Due to the serial connectable phases on the primary side, the use of automotive qualified Si power semiconductors with 600/650 V blocking voltage is possible to reach a DC link voltage up to 800 V.