US 8,264,857 B2 · System and method for a power converter having a resonant circuit

Abstract

A direct current-direct current (DC/DC) converter operated in the resonant mode of operation for converting a direct input voltage into a direct output voltage with a bridge circuit located on the input side and incorporating switching elements, with a resonance circuit incorporating a resonance inductance and a resonance capacitance as well as with a high-frequency transformer for galvanic separation is disclosed, the transformer incorporates at least one primary winding and at least one secondary winding with at least two winding terminals each. The alternating current (AC) output of the bridge circuit is connected to the primary winding and a rectifier bridge with diodes to the secondary winding. A voltage boosting circuit array is connected downstream of the resonant circuit in such a manner that at least one additionally controllable switching element is contained, which is connected in parallel or in series to at least one additional diode or to at least one diode of the rectifier bridge on the secondary side, this array being connected in parallel to the high-frequency transformer so that the additional switching element short-circuits the resonance circuit in a triggered condition so that energy is stored in the resonance inductance and is delivered in the non-triggered condition.

Claims23

Dependent claims

A power converter comprising:

a plurality of input switches coupled to a DC input voltage;
a resonant circuit coupled to the plurality of input switches;
a transformer comprising a first winding coupled to the plurality of input switches;
a rectifier bridge comprising an input port coupled to a second winding of the transformer and an output port configured to be coupled to a load of the power converter;
and
a voltage booster circuit coupled in parallel with the second winding of the transformer and in parallel with the input port of the rectifier bridge, the voltage booster circuit comprising at least one switch configured to provide a low impedance path to the resonant circuit, between terminals of the input port of the rectifier bridge, and in parallel with the second winding of the transformer when the switch is closed,
wherein
the plurality of input switches are configured to charge the first winding and the resonant circuit to a first polarity during a first charge period,
the at least one switch is configured to be closed starting from a beginning of the first charge period until an end of a first portion of the first charge period, the first portion of the first charge period comprising a shorter duration than the first charge period.

6 more elements

A method of operating a power converter comprising a plurality of input switches coupled to a DC input voltage, a resonant circuit coupled to the plurality of input switches, a transformer comprising a first winding coupled to the plurality of switches, a rectifier bridge comprising an input port coupled to a second winding of the transformer and an output port configured to be coupled to a load of the power converter, and a voltage booster circuit coupled in parallel with the second winding of the transformer and in parallel with the input port of the rectifier bridge, the voltage booster circuit comprising at least one switch configured to provide a low impedance path to the resonant circuit, between terminals of the input port of the rectifier bridge, and in parallel with a second terminal of the second winding of the transformer when the at least one switch is closed, the method comprising:

charging the first winding and the resonant circuit according to a first polarity by coupling a first of the plurality of input switches to a first DC voltage during a first charge period;
and
closing the at least one switch at a beginning of a first portion of the first charge period and opening the at least one switch during a remaining portion of the first charge period.

Dependencies are inferred from the claim text.

System and method for a power converter having a resonant circuit

Life of this patent

System and method for a power converter having a resonant circuit

Life of this patent

Abstract

Claims23