Design of LLC converter as start-up power supply for automotive applications

This article deals with the design, simulation and practical realization of LLC converter as start-up power supply for automotive applications. The main topology of the power supply is realized as full-bridge resonant LLC converter in connection with two-phase interleaved PFC converter. Initially, the calculation of main circuit components is done. The main focus was given to the proper design of the transformer because high power levels are required. Transfer characteristic was modified in the way that required operational characteristics for the proposed application can be achieved. Consequently, the simulation verification of the operation is realized. At the end of the paper, a physical sample of the power supply is shown together with the verification of its operation within given operational regions.