Apparatus for resonant converters

摘要

A converter comprises a bridge and a resonant tank coupled between the bridge and an isolation transformer. The converter is configured such that the converter operates at a first constant-gain resonant frequency during a normal operation condition wherein a voltage gain of the converter is essentially insensitive to an output load change and the converter operates at a minimum-gain damping frequency during an abnormal operation condition wherein a voltage gain of the converter is approximately equal to zero.

主权项

1. A converter comprising:
a bridge including at least two switches coupled between an input voltage source and an isolation transformer; a resonant tank coupled to the bridge comprising five resonant components, wherein:
the five resonant components are configured to provide:
a first constant-gain resonant frequency, and wherein a voltage gain of the converter is essentially insensitive to an output load change when the converter operates at the first constant-gain resonant frequency;a minimum-gain damping frequency, and wherein a ratio of the minimum-gain damping frequency to the first constant-gain resonant frequency is in a range from about one and half to three and a voltage gain of the converter is approximately equal to zero when the converter operates at the minimum-gain damping frequency; anda second constant-gain resonant frequency, and wherein the second constant-gain resonant frequency is higher than the minimum-gain damping frequency; and a secondary rectifier coupled to the isolation transformer comprising at least two switches, wherein a dead time is placed between a first gate signal of a first switch of the secondary rectifier and a second gate signal of a second switch of the secondary rectifier.