High power factor isolated buck-type power factor correction converter
First Claim
1. A power converter comprising a single-stage isolated buck-type converter including an isolation transformer, the isolation transformer including a first secondary winding coupled in series with a first rectifier circuit, and a second secondary winding coupled in series with a series combination of a second rectifier circuit and a semiconductor switch, wherein the semiconductor switch is configured to turn on and off based on a parameter of an AC voltage input to the power converter, and to adjust a functional turns ratio of the isolation transformer.
4 Assignments
0 Petitions
Accused Products
Abstract
A regulated power factor corrected power supply apparatus is provided. The apparatus includes an input rectifier circuit for receiving an input AC voltage and outputting a full-wave rectified DC voltage. A single-stage isolated buck-type converter is coupled with the input circuit. The converter circuit comprises an isolated buck-type converter circuit including an isolation transformer. An output rectifier and semiconductor tap switch are coupled to a secondary winding of the isolation transformer. The tap switch couples a larger portion of the secondary winding to an output bulk capacitor during the portions of the input sinewave half-cycle, which are low in amplitude. The tap switch enables the single-stage isolation buck-type converter to operate over a much larger portion of the input sinewave, but also allows the converter to operate at high-efficiency over the majority of the input sinewave.
-
Citations
41 Claims
- 1. A power converter comprising a single-stage isolated buck-type converter including an isolation transformer, the isolation transformer including a first secondary winding coupled in series with a first rectifier circuit, and a second secondary winding coupled in series with a series combination of a second rectifier circuit and a semiconductor switch, wherein the semiconductor switch is configured to turn on and off based on a parameter of an AC voltage input to the power converter, and to adjust a functional turns ratio of the isolation transformer.
-
14. A power converter comprising:
-
a. a first rectifier circuit configured to receive an input AC voltage and to output a full-wave rectified DC voltage; b. a single-stage isolated buck-type converter configured to receive the full-wave rectified DC voltage as input, wherein the single-stage isolated buck-type converter includes an isolation transformer comprising a first secondary winding and a second secondary winding; c. a second rectifier circuit coupled to the first secondary winding; d. a third rectifier circuit coupled to the second secondary winding; e. a tap switch coupled to an output of the third rectifier circuit, wherein the tap switch is configured to adjust a functional turns ratio of the isolation transformer; and f. a bulk capacitor coupled to an output of the second rectifier circuit and the third rectifier circuit, wherein a voltage across the bulk capacitor is a DC voltage output of the power converter. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 40)
-
-
27. A power converter comprising:
-
a. a first rectifier circuit configured to receive an input AC voltage and to output a full-wave rectified DC voltage; b. a first single-stage isolated buck-type converter coupled to the first rectifier including a first isolation transformer having a first primary winding and a first secondary winding, wherein the first primary winding is coupled to the first rectifier circuit and is configured to receive the full-wave rectified DC voltage; c. a second single-stage isolated buck-type converter including a second isolation transformer having a second primary winding and a second secondary winding, wherein the second primary winding is coupled to the first rectifier circuit and is configured to receive the full-wave rectified DC voltage, further wherein when the full-wave rectified DC voltage is above a reference level both the first single-stage isolated buck-type converter and the second single-stage isolated buck-type converter are configured to operate, and when the full-wave rectified DC voltage is below the reference level the first single-stage isolated buck-type converter is configured to operate and the second single-stage isolated buck-type converter is shorted to be inoperable; d. a second rectifier circuit coupled to the first secondary winding of the first isolation transformer; e. a third rectifier circuit coupled to the second secondary winding of the second isolation transformer; and f. a bulk capacitor coupled to an output of the second rectifier circuit and an output of the third rectifier circuit, wherein a voltage across the bulk capacitor is a DC voltage output of the power converter. - View Dependent Claims (28, 29, 30, 31, 32, 33, 41)
-
- 34. A method of operating a power converter comprising changing a functional turns ratio of a single-stage isolated buck-type converter isolation transformer in response to a magnitude of an AC input voltage such that when the magnitude of the AC input voltage is less than a reference level, the functional turns ratio is a first ratio, and when the magnitude of the AC input voltage is equal to or greater than the reference level, the functional turns ratio is a second ratio less than the first ratio, and a DC output voltage from the single-stage isolated buck-type converter divided by the functional turns ratio is greater in magnitude than the magnitude of the AC input voltage.
Specification