System and Method for Estimating Input Power for a Power Processing Circuit

• US 20080315852A1
• Filed: 12/13/2007
• Published: 12/25/2008
• Est. Priority Date: 06/19/2007
• Status: Active Grant

• Current Assignee: Flextronics International USA Incorporated (Flex, Ltd.)
• Original Assignee: Flextronics International USA Incorporated (Flex, Ltd.)
• Inventors: Gugle, Prashant, Jayaraman, Chandrasekaran
• Granted Patent: US 7,906,941 B2
• Time in Patent Office: Days
• US Class Current: 323/285
• CPC Class Codes: G01R 21/133 by using digital technique
• CPC Class Codes: H02M 1/4225 using a non-isolated boost converter
• CPC Class Codes: H02M 3/156 with automatic control of output voltage or current, e.g. switching regulators
• 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

Abstract

A controller for a power processing circuit and a related method of operating the same. In one embodiment, the controller includes a multiplier configured to produce a product of an input current and an input voltage of the power processing circuit. The controller also includes a low-pass filter configured to produce an input power estimate of an input power to the power processing circuit as a function of the product of the input current and the input voltage. In another embodiment, the controller is a power-factor controller and includes a voltage loop compensator configured to produce a voltage compensation signal as a function of an output voltage of the power processing circuit. The controller also includes an input power estimator configured to produce an input power estimate of an input power to the power processing circuit as a function of the voltage compensation signal.

Claims

1. A controller for use with a power processing circuit, comprising:

a voltage loop compensator configured to produce a voltage compensation signal as a function of an output voltage of said power processing circuit; and

an input power estimator configured to produce an input power estimate of an input power to said power processing circuit as a function of said voltage compensation signal.

2. The controller as recited in claim 1 wherein said input power estimator employs a linear relationship to produce said input power estimate.

3. The controller as recited in claim 1 wherein said input power estimator comprises a digital circuit.

4. The controller as recited in claim 3 wherein said output voltage is a scaled, digitized output voltage subtracted from a reference output voltage.

5. The controller as recited in claim 1 wherein said input power estimate is provided to an external system through a communications means.

6. The controller as recited in claim 1 further comprising a pulse width modulator configured to produce a signal to control a duty cycle of a boost power switch in a boost power stage of said power processing circuit.

7. The controller as recited in claim 1 wherein said voltage loop compensator produces said voltage compensation signal as a function of a first error signal derived from a scaled, digitized output voltage subtracted from a reference output voltage, said controller, further comprising:

a multiplier configured to produce a time-dependent current reference signal as a function of a voltage feed-forward signal derived from a scaled, digitized input voltage of said power processing circuit via a feedback circuit and said voltage compensation signal;

a summer configured to produce a second error signal as a function of a current feedback signal derived from a scaled, digitized inductor current of a boost power stage of said power processing circuit and said time-dependent current reference signal;

a current loop compensator configured to produce a current compensation signal from said second error signal; and

a pulse width modulator configured to produce a signal to control a duty cycle of a boost power switch in said boost power stage of said power processing circuit as a function of said current compensation signal.

8. A method of operating a controller of a power processing circuit, comprising:

producing a voltage compensation signal as a function of an output voltage of said power processing circuit with a voltage loop compensator; and

producing an input power estimate of an input power to said power processing circuit as a function of said voltage compensation signal with an input power estimator.

9. The method as recited in claim 8 wherein said input power estimator employs a linear relationship to produce said input power estimate.

10. The method as recited in claim 8 wherein said input power estimator comprises a digital circuit.

11. The method as recited in claim 8 wherein said output voltage is a scaled, digitized output voltage subtracted from a reference output voltage.

12. The method as recited in claim 8 wherein said input power estimate is provided to an external system through a communications means.

13. The method as recited in claim 8 further comprising producing a signal to control a duty cycle of a boost power switch in a boost power stage of said power processing circuit.

14. The method as recited in claim 8 wherein said voltage loop compensator produces said voltage compensation signal as a function of a first error signal derived from a scaled, digitized output voltage subtracted from a reference output voltage, said method, further comprising:

producing a time-dependent current reference signal as a function of a voltage feed-forward signal derived from a scaled, digitized input voltage of said power processing circuit and said voltage compensation signal;

producing a second error signal as a function of a current feedback signal derived from a scaled, digitized inductor current of a boost power stage of said power processing circuit and said time-dependent current reference signal;

producing a current compensation signal from said second error signal; and

producing a signal to control a duty cycle of a boost power switch in said boost power stage of said power processing circuit as a function of said current compensation signal.

15. A power converter, comprising:

a boost power stage including a boost power switch configured to receive an input power with an input current and input voltage and produce an output voltage; and

a controller, including;

a voltage loop compensator configured to produce a voltage compensation signal as a function of said output voltage, and

an input power estimator configured to produce an input power estimate of said input power as a function of said voltage compensation signal.

16. The power converter as recited in claim 15 wherein said input power estimator employs a linear relationship to produce said input power estimate.

17. The power converter as recited in claim 15 wherein said input power estimator comprises a digital circuit.

18. The power converter as recited in claim 15 wherein said output voltage is a scaled, digitized output voltage subtracted from a reference output voltage.

19. The power converter as recited in claim 15 wherein said input power estimate is provided to an external system through a communications means.

20. The power converter as recited in claim 15 wherein voltage loop compensator produces said voltage compensation signal as a function of a first error signal derived from a scaled, digitized output voltage subtracted from a reference output voltage, said controller, further including:

a multiplier configured to produce a time-dependent current reference signal as a function of a voltage feed-forward signal derived from a scaled, digitized input voltage via a feedback circuit and said voltage compensation signal′

a summer configured to produce a second error signal as a function of a current feedback signal derived from a scaled, digitized inductor current of said boost power stage and said time-dependent current reference signal;

a current loop compensator configured to produce a current compensation signal from said second error signal; and

a pulse width modulator configured to produce a signal to control a duty cycle of said boost power switch as a function of said current compensation signal.