Transient DC Bias Suppression Strategy for Dual Active Bridge DC/DC Converters Based on Adaptive Virtual Resistance Compensation

For dual active bridge (DAB) DC/DC converters, DC bias of the inductor current caused by the system parameters variation increases system losses, leads to core saturation, and even jeopardizes the safe and reliable operation. To solve it, a transient DC bias suppression strategy based on adaptive virtual resistance compensation is proposed in this paper. The transient mathematical model of a DAB converter with DC bias is built. On this basis, the phase shift is compensated to simulate the transient characteristic of real-resistance compensation, where the virtual resistance can be dynamically adjusted according to the DC bias. Thus, the transient DC bias can be suppressed without additional circuits, and the simulation results verify its feasibility and effectiveness.