Optimal Strategy of Triple Phase Shift Transient DC Bias for Dual Active Bridge DC-DC Converter

Under the traditional phase shift control, dual active bridge DC-DC converter (DAB) has a transient bias on the inductance current when the phase shift ratio changes suddenly, which leads to increase in the current stress of switch tubes and even unidirectional saturation of the transformer. All those will affect the stable operation of the converter. This paper focuses on quantifying the transient DC bias model on the control of triple phase shift when phase shift ratios change, and then the strategy proposed by the paper can eliminate the DC bias within one switching period and reduce current stress and response time by adjusting the drive signal during the transient transition process. Finally, the proposed strategy is verified by simulation results from Matlab/Simulink software