Electric vehicles can be recharged from any power socket by means of on-board chargers. However, since batteries are becoming increasingly larger and the space available in cars is restricted, conventional chargers containing silicon transistors are reaching their limitations. Therefore, Finepower has developed an on-board charger (OBC) based on gallium nitride that triples the power density of conventional chargers to three kilowatts per litre.
As a result, this water-cooled system has 210 mm × 50 mm × 60 mm in size (without enclosure) and can convert input AC voltages from 85 V to 264 V up to 3600 W to DC voltages ranging from 200 V to 450 V. The maximum output current is 10 A. Thanks to the single-stage IBI-LLC topology (Interleaved Boost-Integrated LLC), an efficiency of up to 97 percent is achieved at 230 V at the input and up to 93 percent at 115 V.
Due to the fully DSP-based regulation, the OBC can be individually adapted to the respective operating conditions. Communication takes place via the standardized CAN bus. For three-phase supply, up to three GaN chargers can be tied together.