Dual loop control for eliminating DC-bias in a DC-DC dual active bridge converter

In bi-directional dual active bridge (DAB) converters, non-ideal behavior of the system components can lead to dc bias in the converter which results in magnetic saturation of the high frequency transformer. This paper proposes adding an extra control loop to overcome this problem. A simulation model has been developed to compare the operation of the converter with ideal and non-ideal components. The results with the extra loop applied to eliminate dc offsets have been shown. Experimental results have been presented to support the simulation results.