DC Short Circuit Fault Analysis of a Triple Active Bridge Converter for Fault Ride-Through Capability

This paper presents the analysis of a triple active bridge (TAB) converter during a DC short circuit fault (SCF). An understanding of the converter operating during SCF is required to design the converter for fault ride-through capability. The analysis is done by evaluating the inductor currents of a TAB converter during rated conditions and during SCF conditions. The analysis aids the design of magnetic components, thermal requirements, and device selection of a converter. The analytical model based on generalized harmonic approximation (GHA) is developed to derive the fault current magnitudes. The impact of different power transfer inductances and different powersharing operating modes of a TAB converter are analyzed in detail for the SCF study. Extensive simulations are carried out in PLECS to demonstrate the operation of TAB converter during SCF. Experimental results on a laboratory prototype are provided for a wide range of operating conditions to validate the results from the analytical model and switching simulations.