Advanced Virtual Resistance Compensation for Transient DC Bias Suppression in Dual Active Bridge Converters

In dual active bridge (DAB) DC/DC converters, transient DC bias in the inductor current is produced due to variations in system parameters, leading to increased RMS value, core saturation, and potential instable operations. To mitigate this issue, we propose a transient DC suppression method based on advanced virtual resistance compensation (VRC). Small-signal analytical models are developed to characterize the proposed VRC-based approach. A compensation loop is then integrated into the control framework to enhance the DAB’s transient performance, dynamically adjusting the phase shift to emulate the transient behavior of real resistance compensation. Experimental results validate that the proposed method effectively suppresses the transient DC bias in the inductor current without introducing additional power loss or compromising power transmission capacity.