Novel Junction Temperature Optimized Operation of Dual Active Bridge Converter Using Extended-Phase-Shift Modulation Featuring SiC MOSFETs

This paper presents the operation of a dual active bridge (DAB) converter using extended-phase-shift (EPS) modulation with a focus on controlling the junction temperatures of the 1.2 kV silicon carbide (SiC) metal-oxide-semiconductor field-effect-transistor (MOSFET) half-bridge power modules. The peak-to-peak variations in the junction temperatures between subsequent operating points will be minimized, consequently softening the impact of junction temperature variations on the module's reliability. Though SiC MOSFETs exhibit several advantages, their packaging technology is still in the initial development phase, and the SiC devices have not reached the reliability levels of their traditional counterparts. Therefore, this scheme will be vital for applications that encounter frequent load/source variations, especially in the converters featuring SiC power devices. This paper discusses the benefit of such a control scheme with the help of the simulation results. It has been shown that using this proposed scheme, an average junction temperature variation of 18 degrees Celsius or less has been achieved for a wide load range apart from the maximum power point under constant voltage operation mode.