Effect of Dead Band and Transient Actions on CTPS Modulation for DAB DC-DC Converter and Solutions

As the key part of the electric vehicle charger with the V2G functions, the isolated dual-active-bridge (DAB) DC-DC converter should possess good current characteristics. The cooperative triple-phase shift (CTPS) modulation for the DAB converter realizes the best inductor current performance. However, the dead band and transient actions deteriorate the actual performance of the CTPS. In this article, the effect is analyzed for the first time, and the analysis results indicate that both the dead band and transient actions cause the dc-bias inductor current and the dc-side flow back currents. The corresponding solutions to eliminate these effects are proposed accordingly. First, a phase shift compensation related to the dead time is added to the ideal phase shifts from CTPS to eliminate the effect of the dead band. Second, the relationship between the three phase shifts is recalculated considering the old values of the phase shifts to eliminate the transient dc-bias currents and flow back currents. The proposed solutions are validated in detail in an experimental way.