Closed-loop efficiency modulation for use in AC powered applications

• US 8,134,848 B2
• Filed: 08/12/2009
• Issued: 03/13/2012
• Est. Priority Date: 08/12/2009
• Status: Active Grant

• Current Assignee: WSOU Investments, LLC (WSOU Holdings, LLC)
• Original Assignee: Alcatel-Lucent SA (Nokia Corporation)
• Inventors: Parrell, Michael W., Gryba, John S., Whittam, Simon P
• Primary Examiner(s): Nguyen, Matthew
• Application Number:
  US12/540,155
• Publication Number:
  US 20110038189A1
• Time in Patent Office: 944 Days
• Field of Search: 363 78- 81, 363/84, 363/89, 363/125, 363/127, 323/282, 323/283, 323/285
• US Class Current: 363/84
• CPC Class Codes: H02J 1/00 Circuit arrangements for dc mains or dc distribution networks
• CPC Class Codes: H02M 1/007 Plural converter units in cascade push-pull DC/DC converters with pre-regulator H02M3/3374; DC-AC converters following a DC-DC stage including a high frequency transformer H02M7/4807; DC-AC converters following a DC-DC conversion stage generating periodically varying voltages H02M7/4826
• CPC Class Codes: H02M 3/158 including plural semiconductor devices as final control devices for a single load
• CPC Class Codes: H02M 7/217 using semiconductor devices only

Abstract

A system and method for closed-loop efficiency modulation for an AC/DC power system is provided. A boost-buck converter and a DC/DC converter connected in series receive a rectified DC feed signal from a AC input signal and deliver a modified DC output to an active load. A controller receives power data at various stages of the system and uses that data to modify a series of trim voltages provided to the feedback inputs of the respective converters to modify each converters output voltage. The controller modifies each converter'"'"'s output voltage to maximize power efficiency while monitoring other data in the system to ensure the system is operating correctly and safely.

Claims

1. A closed-loop system to convert AC power to DC power, the system comprising:

a boost-buck converter unit to receive a first trim voltage and an externally generated first DC feed signal at a first DC voltage, and to generate a second DC feed signal having a second DC voltage based on said first DC voltage and said first trim voltage;

a DC/DC converter unit to receive a second trim voltage and said second DC feed signal, and to generate a DC output supply signal, having a DC output supply voltage based on said second DC voltage and said second trim voltage;

a bus connected to said DC/DC converter unit to carry said DC output supply signal to at least one external load;

a first power loss sensor to generate a first power loss data indicative of a power loss in said boost-buck converter unit, based on said first DC feed signal and said second DC feed signal;

a second power loss sensor to generate a second power loss data indicative of a power loss in said DC/DC converter unit, based on said second DC feed signal and said DC output supply signal; and

a controller to generate a system power efficiency data based on said first and second power loss data, and to generate said first and second trim voltages based on said system power efficiency data to power efficiency of said system.

2. The closed-loop system of claim 1,

wherein the first power loss sensor is configured to sense an amperage of the first DC feed signal and the value of said first DC feed voltage and wherein the first power loss sensor bases the first power loss dataset on the detected amperage of the first DC feed signal, value of said first DC feed voltage, amperage of the second DC feed signal and value of said second DC feed voltage;

and

wherein the second power loss sensor is configured to sense an amperage of the DC supply signal and the value of said DC supply signal voltage and wherein the second power loss sensor bases the second power loss dataset on the detected amperage of the DC supply signal, value of said DC supply signal voltage, amperage of the second DC feed signal and value of said second DC feed voltage.

3. The system of claim 2, further comprising:

a first trim voltage provider to provide the first trim voltage to the feedback input of the boost-buck converter based on a first trim voltage dataset generated by said controller; and

a second trim voltage provider to provide the second trim voltage to the feedback input of the DC/DC converter based on a second trim voltage dataset generated by said controller;

wherein each said trim voltage provider receives a respective trim voltage dataset from said controller.

4. The system of claim 2, further comprising:

an AC Feed Monitor to receive an AC input voltage and to generate said first DC feed signal at a first DC voltage, said AC Feed Monitor further configured to comprise the first power loss sensor and the first trim voltage provider; and

a BUS Feed monitor to receive the DC output supply signal, said BUS Feed Monitor further configured to comprise the second power loss sensor.

5. The system of claim 4, further comprising:

a series of opto-isolators to connect the controller to components of said system of which the controller does not share a common electrical ground.

6. The system of claim 5, further comprising:

a Digital Power Manager comprising said second trim voltage provider, said Digital Power Manager connected to said controller by one of said opto-isolators.

7. The closed-loop system of claim 1, wherein the boost-buck converter unit is a non-isolated single-ended primary inductor converter (SEPIC).

8. The closed-loop system of claim 1, wherein the DC/DC converter unit is selected from a group consisting of a flyback converter, push-pull converter, and forward converter.

9. A system of maximizing power efficiency in an AC/DC power conversion system, the system comprising:

a first generating means to generate a first trim dataset to provide a first trim voltage to a first DC/DC conversion means through a second generating means, and a second trim dataset to provide a second trim voltage to a second DC/DC conversion means through a third generating means;

a second generating means to generate the first trim voltage based on said first trim dataset;

a third generating means to generate the second trim voltage based on said second trim dataset;

a first sensing means to sense a first DC feed signal into the input and a second DC feed signal from the output of said first DC/DC conversion means and to create a first power loss dataset indicative of power loss in said first DC/DC conversion means;

a second sensing means to sense the second DC feed signal into the input and a DC output supply signal from the output of said second DC/DC conversion means and to create a second power loss dataset indicative of power loss in said second DC/DC conversion means; and

a controlling means, said controlling means comprised to;

receive said first and second power loss datasets from said first and second sensing means;

calculate a first power efficiency dataset of said system based on said first and second power loss datasets;

modify at least one of the first and second trim voltage datasets to a new value to produce a second power efficiency dataset;

compare said first and second power efficiency datasets;

determine when a termination condition has occurred; and

halt further modification once said termination condition has occurred.

10. A method of maximizing power efficiency in an AC/DC power conversion system, the method comprising:

i. generating, by a controller, a first trim dataset to provide a first trim voltage to a boost-buck converter through a first trim voltage provider, and a second trim dataset to provide a second trim voltage to a DC/DC converter through a second trim voltage provider;

ii. generating, by said first trim voltage provider, said first trim voltage based on said first trim voltage dataset;

iii. generating, by said second trim voltage provider, a second trim voltage based on said second trim voltage dataset;

iv. creating, by a first power loss sensor, a first power loss dataset indicative of a power loss in said boost-buck converter unit, based on a first DC feed signal into the input and a second DC feed signal from the output of said boost-buck converter unit;

v. creating, by a second power loss sensor, a second power loss dataset indicative of a power loss in a DC/DC converter unit, based on said second DC feed signal into the input and a DC output supply signal from the output of said DC/DC converter unit;

vi. receiving, by said controller, said first and second power loss datasets from said first and second power loss sensors;

vii. calculating, by said controller, a first power efficiency dataset of said system based on said first and second power loss datasets;

viii. modifying, by said controller, at least one of the first and second trim voltage datasets to a new value and repeating steps ii. through vii. to produce a second power efficiency dataset

ix. comparing, by said controller, said first and second power efficiency datasets; and

x. repeating steps viii. and ix. until the controller determines a termination condition has occurred.

11. The method of claim 10,

wherein the first power loss sensor creates the first power loss dataset by detecting amperages of the first and second DC feed signals, and the values of first and second DC feed voltages;

and

wherein the second power loss sensor creates the second power loss dataset by detecting amperages of the second DC feed signal and the DC output supply signal and the values of the second DC feed voltage and a DC output supply signal voltage.

12. The method of claim 10,

wherein an AC Feed Monitor is configured to comprise the first power loss sensor and the first trim voltage;

and

wherein a BUS Feed Monitor is configured to comprise the second power loss sensor.

13. The method of claim 10, further comprising:

receiving, by a series of opto-isolators, said first and second power loss datasets; and

sending, from the series of opto-isolators to the controller, said first and second power loss datasets.

14. The method of claim 13, wherein a Digital Power Manager comprises the second trim voltage provider, wherein the Digital Power Manager receives said first trim voltage dataset from the controller through an opto-isolator.

15. The method of claim 10, wherein the boost-buck converter is a non-isolated single-ended primary inductor converter (SEPIC).

16. The method of claim 10, wherein the DC/DC converter is selected from a group consisting of a flyback converter, push-pull converter, and forward converter.