Power factor correction circuit

• US 10,122,262 B1
• Filed: 07/05/2018
• Issued: 11/06/2018
• Est. Priority Date: 07/05/2018
• Status: Active Grant

• Current Assignee: NXP USA, Inc. (NXP Semiconductors NV)
• Original Assignee: NXP USA, Inc. (NXP Semiconductors NV)
• Inventors: Wang, Dechang, Zhang, Yangjie, Gao, Xiang, Wang, Lingling
• Primary Examiner(s): Nash, Gary
• Application Number:
  US16/028,234
• Time in Patent Office: 124 Days
• Field of Search: 31840026, 323358, 363 64, 363 76, 363 77, 363 84, 363 88- 90, 363 93, 363127
• CPC Class Codes: G05F 1/70 Regulating power factor; Regulating reactive current or power
• CPC Class Codes: H02J 50/10 using inductive coupling
• CPC Class Codes: H02M 1/4233 using a bridge converter comprising active switches
• CPC Class Codes: H02M 7/219 in a bridge configuration
• CPC Class Codes: Y02B 70/10 Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes
• CPC Class Codes: Y02P 80/10 Efficient use of energy, e.g. using compressed air or pressurized fluid as energy carrier

Abstract

A bridgeless power factor correction (PFC) circuit has first and second nodes, and first and second current paths connected between the first and second nodes. The first current path includes a first semiconductor device and a first switch element, and the second current path includes a second semiconductor device and a second switch element. One of the first and the second current paths further includes first and second sensing elements that are oppositely connected in series.

Claims

1. A bridgeless power factor correction (PFC) circuit, comprising:

a first node and a second node, wherein one of the first and second nodes is connected to a power supply, and the other of the first and second nodes is connected to the power supply through an inductor;

a first current path including a first semiconductor device and a first switch element, wherein the first current path is connected between the first and second nodes and configured to allow current to flow during a positive cycle of the power supply to charge the inductor; and

a second current path including a second semiconductor device and a second switch element, wherein the second current path is connected between the first and second nodes and configured to allow current to flow during a negative cycle of the power supply to charge the inductor,

wherein one of the first and the second current paths further comprises a first sensing element and a second sensing element, wherein the first and second sensing elements are oppositely connected in series.

2. The circuit of claim 1, wherein the first and second switch elements are configured to be controllable to conduct currents in the respective current paths.

3. The circuit of claim 1, wherein each of the first and the second semiconductor devices is one of a diode, a diode connected transistor, and a transistor.

4. The circuit of claim 1, wherein each of the first and second sensing elements is one of a current transformer and a Hall sensor.

5. The circuit of claim 1, wherein cathodes of the first and second sensing elements are connected together.

6. The circuit of claim 1, wherein the serial connection of the first and second sensing elements is connected between the semiconductor device and the switch element of the respective current path.

7. The circuit of claim 1, wherein the serial connection of the first and second sensing elements is connected between the switch element of the respective current path and one of the first and the second nodes.

8. A power converter circuit, comprising:

a first branch comprising a first current conduction element and a second current conduction element, wherein a first node is located between the first current conduction element and the second current conduction element, and is couplable to a first terminal of a power supply; and

a second branch connected in parallel with the first branch, wherein the second branch comprises a first switch element, a second switch element, a first sensing element, and a second sensing element, wherein a second node between the first switch element and the second switch element is couplable to a second terminal of the power supply through an inductor,

wherein the first and second sensing elements are oppositely connected, and a series connection of the first and second sensing elements is coupled between the second node and one of the first and second current conduction elements, and

wherein one of the first and second sensing elements samples current during a positive cycle of the power supply, while the other of the first and second sensing elements samples current during a negative cycle of the power supply.

9. The power converter circuit of claim 8, wherein each of the first and second current conduction elements is one of a diode, a diode connected transistor, and a transistor.

10. The power converter circuit of claim 8, wherein the first and the second switch elements are transistors that are controllable to be conductive to conduct currents to and/or from the second node.

11. The power converter circuit of claim 8, wherein each of the first and second sensing elements is one of a current transformer and a Hall sensor.

12. The power converter circuit of claim 8, wherein cathodes of the first and second sensing elements are connected to each other.

13. The power converter circuit of claim 8, wherein the first sensing element is a current transformer connected between the second node and the second sensing element, and the first sensing element comprises:

a first winding on a first side, wherein the first winding has two terminals providing a sensed current;

a second winding and a third winding on a second side, wherein each of the second and third windings has a terminal connected together, and another terminal connected together to the second sensing element.

14. The power converter circuit of claim 13, wherein the second sensing element is a current transformer connected between the first sensing element and the one of the first and second switch elements, and the second sensing element comprises:

a first winding on a first side, wherein the first winding has two terminals providing a sensed current;

a second winding and a third winding on a second side, wherein each of the second and third windings has a terminal connected in common, and another terminal connected together to the terminals of the second and third windings on the second side of the first sensing element.

15. A system having first and second output terminals, the system comprising:

a power supply having a first terminal and a second terminal;

an inductor having a first terminal coupled to the second terminal of the power supply, and a second terminal;

first and second conduction devices respectively coupled between the first terminal of the power supply and the first and second output terminals;

first and second switch devices respectively coupled between the second terminal of the inductor and the first and second output terminals; and

first and second current sensing devices connected in series between the second terminal of the inductor and one of the first and second output terminals,

wherein one of the first and second current sensing devices samples current through a respective one of the first or second switch devices during a first half cycle of the power supply, while the other of the first and second current sensing devices samples current through the one of the first or second switch devices during a second half cycle of the power supply.

16. The system of claim 15, wherein the first and second current sensing devices are coupled between the first switch device and the first output terminal.

17. The system of claim 15, wherein the first and second current sensing devices are coupled between the second terminal of the inductor and the second switch device.

18. The system of claim 15, wherein cathodes of the first and second current sensing devices are coupled to each other.

19. The system of claim 15, wherein each of the first and second current sensing devices is one of a current transformer and a Hall sensor.

20. The system of claim 15, wherein each of the first and second conduction devices is one of a diode, a diode-connected transistor, and a transistor.