Power controller having active voltage balancing of a power supply

• US 9,444,320 B1
• Filed: 03/14/2013
• Issued: 09/13/2016
• Est. Priority Date: 04/16/2012
• Status: Active Grant

• Current Assignee: Fujifilm Healthcare Americas Corporation (Fujifilm Holdings Corporation)
• Original Assignee: Performance Controls, Inc. (Fujifilm Holdings Corporation)
• Inventors: Boodhansingh, Anthony J., Fenstermacher, Brian J., Weggel, Craig R., Yost, Donald A.
• Primary Examiner(s): GBLENDE, JEFFREY A
• Application Number:
  US13/828,743
• Time in Patent Office: 1,279 Days
• Field of Search: 363/34, 363/37, 363/65, 363 67- 72, 363/124, 363/125, 363/131
• US Class Current: 1/1
• CPC Class Codes: H02M 3/285 Single converters with a plurality of output stages connected in parallel parallel operation of a plurality of converters in dc distribution networks H02J1/10
• CPC Class Codes: H02M 3/33561 having more than one ouput with independent control
• CPC Class Codes: H02M 7/153 arranged for operation in parallel
• CPC Class Codes: H02M 7/487 Neutral point clamped inverters

Abstract

A power controller includes a plurality of power supply output circuits and a multi-level converter connected to the plurality of power supply output circuits to receive a plurality of sets of voltages. The multi-level converter is configured to supply power to a load from a plurality of output terminals. An observer module is operably coupled to the multi-level converter to selectively control multi-level converter common-mode voltage with respect to the plurality of power supply output terminals.

Claims

1. A single-phase power controller comprising:

a multi-level converter having a plurality of input terminals configured to connect to a power supply and receive a plurality of sets of voltages, the multi-level converter configured to supply single-phase power to a load from a plurality of converter output terminals;

an observer module operably coupled to the multi-level converter to selectively control multi-level converter common-mode voltage with respect to the plurality of power supply output terminals; and

a common mode control loop circuit configured to provide a common mode command signal, wherein the observer module is configured to selectively control use of the common mode command signal to control the multi-level converter common mode voltage on the converter output terminals based on the voltage across the multi-level converter output terminals.

4. The single-phase power controller of claim 1 wherein the observer module is configured to selectively control the multi-level converter common mode voltage on the converter output terminals based on the operating state of the power supply.

2. A single-phase power controller comprising:

a multi-level converter having a plurality of input terminals configured to connect to a power supply and receive a plurality of sets of voltages, the multi-level converter configured to supply single-phase power to a load from a plurality of converter output terminals;

an observer module operably coupled to the multi-level converter to selectively control multi-level converter common-mode voltage with respect to the plurality of power supply output terminals; and

a primary control loop configured to provide an output command signal and a common mode control loop circuit configured to provide a common mode command signal, wherein the observer module is configured to control the multi-level converter common mode voltage on the converter output terminals by selectively combining the output command signal and the common mode command signal.

20. The single-phase power controller of claim 2 wherein the observer module is configured to selectively control the multi-level converter common mode voltage on the converter output terminals based on the operating state of the power supply.

3. A single-phase power controller comprising:

a multi-level converter having a plurality of input terminals configured to connect to a power supply and receive a plurality of sets of voltages, the multi-level converter configured to supply single-phase power to a load from a plurality of converter output terminals; and

an observer module operably coupled to the multi-level converter to selectively control multi-level converter common-mode voltage with respect to the plurality of power supply output terminals, wherein the observer module is configured to selectively control the multi-level converter common mode voltage on the converter output terminals of the multi-level converter when a voltage across the converter output terminals exceeds a voltage across a pair of the plurality of output terminals.

5. A power controller comprising:

a power supply having a plurality of power supply output circuits, each power supply output circuit configured to provide a set of voltages;

a primary control loop configured to provide an output command signal, wherein the output command comprises a first command signal related to a voltage at a first terminal of the plurality of output terminals and a second command signal related to a voltage at a second terminal of the plurality of output terminals;

a multi-level converter connected to the plurality of power supply output circuits to receive each associated set of voltages, the multi-level converter operably connected to the primary control loop and configured to supply power to a load from a plurality of multi-level converter output terminals based on the output command signal;

a common mode control loop configured to provide a common mode command signal based on an indication of a voltage imbalance between the sets of voltages of the plurality of power supply output circuits; and

an observer module operably coupled to the primary control loop to receive the first command signal and the second command signal, wherein the observer module is configured to selectively change the output command signal based on the first command signal and the second command signal, the observer module being further operably coupled to the multi-level converter to selectively change the output command based on the common mode command signal.

6. The power controller of claim 5 wherein the plurality of power supply output circuits comprise:

a first power supply output circuit configured to provide a first set of voltages to the multi-level converter, the first set of voltages comprising a first voltage and a second voltage, the second voltage being greater than the first voltage;

a second power supply output circuit configured to provide a second set of voltages to the multi-level converter, the second set of voltages being connected in series to the first voltage; and

a third power supply output circuit configured to provide a third set of voltages to the multi-level converter, the third set of voltages being connected in series to the second voltage.

7. The power controller of claim 6 wherein the common mode control loop is configured to provide the common mode command signal based on the second set of voltages and the third set of voltages.

8. The power controller of claim 6 wherein the common mode control loop is configured to provide the common mode command signal based on a current of the second power supply output circuit and a current of the third power supply output circuit.

9. The power controller of claim 6 wherein the common mode control loop is configured to provide the common mode command signal based on a common mode voltage across the plurality of multi-level converter output terminals.

10. The power controller of claim 6 wherein the observer module is configured to selectively change the output command signal when the second power supply output circuit provides the second set of voltages to the load by means of the multi-level converter and the third power supply output circuit provides the third set of voltages to the load by means of the multi-level converter.

11. The power controller of claim 6 wherein the observer module is configured to selectively change the output command signal based on presence of current in at least one of the second power supply output circuit and the third power supply output circuit.

12. The power controller of claim 6 wherein the observer module is configured to selectively change the output command signal when voltage across the output terminals exceeds a voltage across the first set of voltages.

13. The power controller of claim 6 wherein the observer module selectively controls the multi-level converter common mode voltage on the converter output terminals based on current through the multi-level converter output terminals.

14. The power controller of claim 6 wherein the observer module is configured to selectively change the output command signal based on at least one of a derivative of the second set of voltages and a derivative of the third set of voltages.

15. The power controller of claim 6 wherein the power supply comprises a controller operably connected to a converter configured to drive each of the power supply output circuits.

16. The power controller of claim 6 wherein the power supply comprises:

a first controller operably connected to a first converter to drive the first power supply output circuit; and

a second controller operably connected to a second converter to drive each of the second and third power supply output circuits.

17. The power controller of claim 6 wherein the power supply comprises:

a first controller operably connected to a first converter comprising the first power supply output circuit; and

a second controller operably connected to a second converter and a third converter, the second converter comprising the second power supply output circuit and the third converter comprising the third power supply output circuit.

19. The power controller of claim 5 wherein the power controller is a single-phase power controller and the multi-level converter is configured to supply single-phase power from the output terminals.

18. A method of supplying single-phase power to a load using a multi-level converter wherein the load is connected across the multi-level converter output terminals of the multi-level converter, the method comprising:

supplying an output command signal to the multi-level converter, the output command signal being indicative of a desired single-phase voltage across the output terminals;

supplying a plurality of sets of voltages to input terminals of the multi-level converter;

when the desired voltage across the converter output terminals does not exceed a selected voltage, supplying power to the multi-level converter via only of one of the sets of voltages; and

when the desired voltage across the converter output terminals exceeds the selected voltage,

supplying power to the multi-level converter via each of the sets of voltages; and

changing the output command signal provided to the multi-level converter based on a voltage imbalance between two of the sets of voltages and to control multi-level converter common-mode voltage with respect to the plurality of power supply output terminals and to control common mode voltage on the converter output terminals of the multi-level converter.