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US 8,804,376 B2Granted
DC/DC converter with selectable coupling ratio and power inverter using the same
AssigneeCyber Power Systems, Inc.
InventorsYuchih Lin, Shao-Chung Chen
Life of this patent
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Abstract
The DC/DC converter has a full bridge circuit, a transformer and a rectifying unit. The full bridge circuit is connected to a source DC voltage. The transformer is connected to full bridge circuit and receives the source DC. The transformer has a stationary winding and at least one selectable winding connected in series. If the source DC voltage is lower than a threshold value, the switch is turned on to increase the coupling ratio of the transformer. Therefore, the transformer converts the source DC to a DC voltage in a required voltage level.
Claims8
A DC/DC converter with selectable coupling ratio, characterized in that the DC/DC converter comprises:
- a full bridge circuit having four power transistors to form two input terminals and two output terminals, wherein the two input terminals are adapted to connect to a source DC voltage;
- a transformer comprising
- a primary side having a primary winding connected to the two output terminals of the full bridge circuit;
- a secondary side having M secondary windings that include a stationary winding and multiple selectable windings, wherein M≧2, and each of the secondary windings has a first end and a second end;
- a rectifying unit formed by P diodes, wherein P=2M+2, every two of the diodes are connected in series at a node to form a branch, and all the branches are connected in parallel;
- the first end and the second end of the stationary winding connected to the two nodes of two of the branches respectively;
- the first ends of the multiple selectable windings connected, through multiple switches respectively, to the nodes of other branches that are not connected to the stationary winding;
- wherein one of the multiple switches of the selectable windings is selected based on a magnitude of the source DC voltage and turned on so that a coupling ratio of the transformer is changed to produce a DC voltage with a required voltage level at the secondary side of the transformer.
5 more elements
A DC/DC converter with selectable coupling ratio comprising:
- a full bridge circuit having four power transistors to form two input terminals and two output terminals, wherein the two input terminals are adapted to connect to a source DC voltage;
- a transformer comprising a primary side and a secondary side, wherein the primary side has a primary winding, and the secondary side has
- a stationary winding having two ends;
- and
- a selectable winding having two ends, wherein one of the two ends is connected to a switch, the other end is connected to the stationary winding in series;
- a rectifying unit formed by six diodes, wherein every two of the diodes are connected in series at a node to form a first branch, a second branch and a third branch, and all the branches are connected in parallel;
- the switch connected to the selectable winding is further connected to the node of the first branch;
- the two ends of the stationary winding are connected to the nodes of the second branch and the third branch respectively;
- the switch is controlled to turn on to connect the stationary winding and the selectable winding in series and to increase a coupling ratio of the transformer when the source DC voltage is smaller than a threshold value.
6 more elements
A power inverter comprising:
- a full bridge circuit having four power transistors to form two input terminals and two output terminals, wherein the two input terminals are adapted to connect to a source DC voltage;
- a transformer comprising
- a primary side having a primary winding connected to the two output terminals of the full bridge circuit;
- a secondary side having M secondary windings that include a stationary winding and multiple selectable windings, wherein M≧2, and each of the secondary windings has a first end and a second end;
- a rectifying unit formed by P diodes, wherein P=2M+2, every two of the diodes are connected in series at a node to form a branch, and all the branches are connected in parallel;
- the first end and the second end of the stationary winding connected to two nodes of two of the branches respectively;
- the first ends of the multiple selectable windings connected, through multiple switches respectively, to the nodes of the branches that are not connected to the stationary winding;
- wherein one of the multiple switches is selected and turned on based on a voltage level of the source DC voltage so that a coupling ratio of the transformer is changed to produce a DC voltage required at the secondary side, and the DC voltage is further rectified by the rectifying unit to generate a rectified DC voltage;
- a DC/AC converter connected to the rectifying unit and converting the rectified DC voltage to an AC voltage required.
6 more elements
Dependencies are inferred from the claim text.