Light Load Efficiency Improvements in Dual Active Bridge Converters via Dead time Control

Abstract

Many converters suffer from poor efficiency at light loads even though much of their lifetime is spent at lightly loaded conditions. During normal operation, the dual active bridge (DAB) family of converters loses soft switching at low power levels, leading to poor light-load efficiency. In this paper a control approach for DAB converter is investigated that enhances their light-load efficiency via dead time control. A model is developed that captures the relationship between output power and dead time, and is used to formulate a control approach for light-load operation. Experimental results from a prototype converter validate the proposed approach.