Safe start-up procedures of isolated bi-directional DC-DC converter

This paper presents a safe start-up procedures of an isolated bi-directional DC-DC converter in buck and boost modes. This converter has been developed as a part of multifunctional up to 4 kW power supply system that uses a high voltage (450 V) DC-link. The isolated bi-directional DC-DC converter can charge 28 V batteries and supply auxiliary low voltage DC loads. Additionally, the isolated bidirectional converter can also draw power from the batteries or from truck´s engine driven alternator to keep maintain the high voltage DC-link. Modulation strategies, start-up procedures and control of this converter have been validated by using the Matlab SymPowerSystems Toolboxes and finally, they have been also experimentally verified.