Highly dynamic gallium-nitride DC-DC converter for 48 V systems
The 48 V system is currently established as a low-voltage supply for high-power loads and auxiliaries that do not justify the cost and safety issues associated with high voltage systems, such as small electric drives in mild hybrids, active chassis systems, and electric turbo chargers. The high dynamics of such loads present high challenges for the supply as they often involve highly dynamic transients and fluctuations. In electrical active chassis systems that are currently under development, for example, road irregularities and critical drive situations are reflected in the power demand as well as sudden direction changes. We will present a fast bidirectional multiphase Gallium-Nitride (GaN) DC-DC converter between the 12 V supply and the 48 V island system for high-power auxiliaries, which reduces or eliminates the present need for an additional 48 V energy storage, can follow the fast dynamics of typical loads, cope with rapid changes of the power flow direction, and compensate the 12-V voltage fluctuations originating from the 12-V generator as well as sudden load changes of other units. We will present a fast combination of feed-back and feed-forward control that keeps the voltage of the active suspension within an interval of +/- 2 V.
