Comparison of multi-port converter topologies with bidirectional energy flow for automotive energy net applications

Three-port converters with bidirectional energy flow have been investigated for the 14V/42V automotive energy net. The three-port converters are designed to interlink the two energy nets and a double-layer capacitor to relieve the battery from current stress and to stabilize the energy net voltages. The investigated converter topologies include a three-port converter that requires only three MOSFETS as switching devices. Analyses of the converter topologies have been performed and a prototype converter of the most promising converter, the three-switch topology, has been built and tested to prove theoretical predictions. Measurements are in good correlations with results from the analyses.