Bidirectional flyback DC-DC converter for hybrid electric vehicle: Utility, working and PSPICE computer model

There is a trend in the automotive industry to replace more engine driven mechanical and hydraulic loads with electrical loads, due to higher efficiency, safety requirement and driver´s comfort. All of these new functions require the application of power electronics, by making use of dc/dc (conventional low power loads), dc/ac (air conditioning systems) and ac/dc (battery charging) converters. This paper first introduces the advance power system for hybrid electric vehicles (HEVs). The role of bidirectional dc-dc converter in the architecture is, then, explained. Out of several bidirectional dc-dc converter, flyback configuration is selected as it provides isolation between high voltage and low voltage side. Its working is also explained. Finally, a PSPICE model of the converter is proposed and results obtained for forward and backward conduction are reported.