DC/DC-converter for modular coupling of 48 V battery packs to a high voltage DC bus

A DC/DC dual active bridge converter for connecting modular low voltage battery packs to a high voltage DC bus is presented. It enables easy scalability of the power output. The converter topology allows the use of zero voltage switching which enables a reduction of the switching losses. But in some operation points this feature is lost. To maximize the efficiency of the converter a variable frequency modulation scheme was developed. The experimental results show an improvement of the efficiency curve.