Digitally-Controlled Power Factor Correction Circuits, Methods and Articles of Manufacture

• US 20130162224A1
• Filed: 12/22/2011
• Published: 06/27/2013
• Est. Priority Date: 12/22/2011
• Status: Active Grant

• Current Assignee: B/E Aerospace, Inc. (Raytheon Technologies Corporation d/b/a RTX)
• Original Assignee: B/E Aerospace, Inc. (Raytheon Technologies Corporation d/b/a RTX)
• Inventors: Eckel, David P., Walsh, Andrew B., Secilmis, Seckin K., Johannessen, Eric, Sam, Luis
• Granted Patent: US 9,496,782 B2
• Time in Patent Office: Days
• US Class Current: 323/205
• CPC Class Codes: H02M 1/42 Circuits or arrangements for compensating for or adjusting power factor in converters or inverters
• CPC Class Codes: H05B 45/355 Power factor correction [PFC]; Reactive power compensation
• CPC Class Codes: H05B 45/38 using boost topology
• CPC Class Codes: H05B 45/385 using flyback topology
• CPC Class Codes: Y02B 20/30 Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED]

Abstract

Digitally-controlled power factor correction circuits, methods, and articles of manufacture are disclosed. A disclosed power supply comprises a power factor correction circuit including a switch, an inductor having a first terminal connected to an input voltage, and a second terminal connected to the switch, a storage capacitor and a load, a value of the inductor selected to operate the power factor correction circuit in discontinuous conduction mode, and a controller programmed to operate the switch to increase a power factor of the power supply.

Claims

1. A power supply comprising a power factor correction circuit including:

a switch;

an inductor having a first terminal connected to an input voltage, and a second terminal connected to the switch, a storage capacitor and a load, a value of the inductor selected to operate the power factor correction circuit in discontinuous conduction mode; and

a controller programmed to operate the switch to increase a power factor of the power supply.

2. A power supply as defined in claim 1, wherein the inductor is selected to eliminate at least one of a zero-crossing detector or a current sensor.

3. A power supply as defined in claim 1, further comprising a diode connecting the inductor to the load and the storage capacitor.

4. A power supply as defined in claim 1, wherein the controller is programmed to periodically adjust a switching frequency of the switch to reduce electromagnetic interference.

5. A power supply as defined in claim 1, wherein the controller is programmed to operate the switch to spread electromagnetic interference across a range of frequencies.

6. A power supply as defined in claim 1, wherein the controller is selectively configurable to operate the power supply at two or more switching frequencies.

7. A power supply as defined in claim 1, wherein the controller is programmed to not change the operation of the switch while an output voltage of the power factor correction circuit is within a range of voltages that includes a target output voltage.

8. A power supply as defined in claim 7, wherein the controller is programmed to not change the operation of the switch to reduce at least one of an oscillation, an instability, or an electromagnetic interference.

9. A power supply as defined in claim 1, wherein the controller is programmed to decrease an output voltage of the power factor correction circuit at a faster rate than the output voltage is increased.

10. A power supply as defined in claim 1, wherein the controller is programmed to adjust a pulse width associated with an operation of the switch based on an output voltage of the power factor correction circuit.

11. A power supply as defined in claim 1, wherein the controller is programmed to discontinue operation of the switch when a supply voltage drops below a threshold.

12. A method of controlling a switch of a power factor correction circuit, the method comprising:

adjusting a pulse width associated with an operation of the switch based on an output voltage of the power factor correction circuit; and

deviating a switching frequency of the switch from a nominal switching frequency to reduce electromagnetic interference.

13. A method as defined in claim 12, further comprising periodically deviating the switching frequency by a pseudo-random amount.

14. A method as defined in claim 12, further comprising adjusting the nominal switching frequency to substantially correspond to an input voltage frequency.

15. A method as defined in claim 12, further comprising not adjusting the operation of the switch when an output voltage of the power factor correction circuit is within a range of voltages that includes a target output voltage.

16. A method as defined in claim 12, further comprising not adjusting the operation of the switch to reduce at least one of an oscillation, an instability, or an electromagnetic interference.

17. A method as defined in claim 12, further comprising decreasing an output voltage of the power factor correction circuit at a faster rate than the output voltage is increased.

18. A method as defined in claim 12, further comprising discontinuing the operation of the switch when an inadequate supply voltage condition is detected.

19. A tangible article of manufacture storing machine-readable instructions that, when executed, cause a machine to at least carry out the method of claim 12.

20. A power supply comprising:

a power source; and

a power factor correction circuit including;

a switch;

a transformer having a first side connected to the power source and the switch, and a second side connected to a storage capacitor and a load; and

a controller programmed to operate the switch to control a power factor of the power supply.

21. A power supply as defined in claim 20, wherein the controller is programmed to operate the switch without reference to a detected zero-crossing and without reference to a sensed current.

22. A power supply as defined in claim 20, wherein the controller is programmed to deviate a switching frequency of the switch from a nominal switching frequency by a pseudo-random amount to reduce electromagnetic interference.