Power supply device having improved power conversion efficiency in light load conditions

摘要

There is provided a phase shift full bridge (PSFB) type power supply device controlling a switching on time of lagging leg switches according to a load state. The power supply device includes a power supply unit supplying preset DC power by switching input power using a full bridge by a phase shift method; and a control unit controlling a switching time of a switch of the full bridge according to a load state in which the DC power is received from the power supply unit.

主权项

1. A power supply device, comprising:
a power supply unit supplying preset DC power by switching input power using a full bridge by a phase shift method; and a control unit controlling a switching time of a switch of the full bridge according to a load state in which the DC power is received from the power supply unit; wherein the switch of the full bridge of the power supply unit includes:
first and second leading leg switches; andfirst and second lagging leg switches; wherein the control unit maintains a switching on time of at least one of the first and second lagging leg switches as before, in the case that the load current is above a predetermined load current; and wherein the control unit delays a switching on time of at least one of the first and second lagging leg switches, in the case that the load current is below the predetermined load current; wherein the switching on time is a point in time of switching on the first or second lagging leg.