System for providing multiple power conversion operations

• US 6,803,677 B2
• Filed: 03/20/2002
• Issued: 10/12/2004
• Est. Priority Date: 03/20/2002
• Status: Active Grant

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Johnson, James P., Algrain, Marcelo C.
• Primary Examiner(s): TOATLEY, GREGORY J
• Application Number:
  US10/100,923
• Publication Number:
  US 20030178889A1
• Time in Patent Office: 937 Days
• Field of Search: 307/43, 307/44, 307/46
• US Class Current: 307/44
• CPC Class Codes: H02M 1/009 having two or more independently controlled outputs for DC-DC converter with intermediate AC H02M3/33561
• CPC Class Codes: H02M 3/33584 Bidirectional converters
• CPC Class Codes: H02M 5/12 for conversion of voltage or current amplitude only
• CPC Class Codes: H02M 7/48 using discharge tubes with control electrode or semiconductor devices with control electrode

Abstract

A system may be provided to perform multiple power conversion operations. The system may include a transformer interconnected between a high voltage DC bus and a low voltage DC bus, and an AC load connected to the transformer through an AC power supply line. The system may be configured to simultaneously provide power from the low voltage DC bus to the high voltage DC bus and the AC load, through the transformer. Further, the system may also be configured to simultaneously provide power from the high voltage DC bus to the low voltage DC bus and the AC load, through the transformer. And, the system may be configured to simultaneously provide power from a shore power source to the AC load, and, to the low voltage DC bus and high voltage DC bus through the transformer.

Claims

1. A method performed by a multi-function system including a high voltage DC bus, a low voltage DC bus, and a transformer connected between the high voltage DC bus and the low voltage DC bus, the method comprising:

selectively performing at least one of;

simultaneously providing power from the low voltage DC bus to the high voltage DC bus and an AC load through the transformer;

simultaneously providing power from the high voltage DC bus to the low voltage DC bus and the AC load through the transformer; and

simultaneously providing power from a shore power source to the AC load, and to the low voltage DC bus and high voltage DC bus through the transformer.

2. The method of claim 1, wherein simultaneously providing power from the high voltage DC bus to the low voltage DC bus and the AC load through the transformer includes:

providing a DC signal from the high voltage DC bus to an inverter circuit;

inverting the DC signal to produce an AC signal; and

providing the AC signal to the transformer.

3. The method of claim 2, wherein the AC signal is a high frequency AC signal.

4. The method of claim 2, wherein inverting the DC signal includes:

inverting the DC signal using sine triangle pulse width modulation to produce a high frequency AC signal.

5. The method of claim 1, wherein simultaneously providing power from the high voltage DC bus to the low voltage DC bus and the AC load through the transformer includes:

rectifying a high frequency AC signal received from the transformer to produce a DC signal;

filtering the DC signal;

providing the filtered DC signal to the low voltage DC bus;

filtering another high frequency AC signal received from the transformer; and

providing the filtered another AC signal to the AC load.

6. The method of claim 5, wherein providing the filtered another AC signal to the AC load includes:

providing power to at least one of a first AC load associated with a first AC voltage and a second AC load associated with a second AC voltage different than the first AC voltage.

7. The method of claim 6, wherein providing power to at least one of the first AC load and the second AC load includes:

providing power to at least one of the first AC load and the second AC load based on a position of a switch associated with the first AC load and a position of at least one other switch associated with the second AC load.

8. The method of claim 2, wherein the inverter circuit may operate as a rectifier circuit to rectify a second AC signal received from the transformer to provide a DC signal to the high voltage DC bus.

9. The method of claim 1, wherein simultaneously providing power from the low voltage DC bus to the high voltage DC bus and an AC load through the transformer includes:

providing a DC signal from the low voltage DC bus to a inverter circuit;

inverting the DC signal to produce an AC signal; and

providing the AC signal to the transformer.

10. The method of claim 9, wherein inverting the DC signal includes:

inverting the DC signal using sine triangle pulse width modulation to produce the AC signal.

11. The method of claim 9, wherein providing the AC signal to the transformer includes:

rectifying a high frequency AC signal provided by the transformer to produce a DC signal;

filtering the DC signal;

providing the filtered DC signal to the high voltage DC bus;

filtering another high frequency AC signal received from the transformer; and

providing the filtered another AC signal to the AC load.

12. The method of claim 11, wherein the AC load is positioned on the side of the transformer connected to the low voltage DC bus.

13. The method of claim 11, wherein providing the filtered another AC signal to the AC load includes:

providing power to at least one of a first AC load associated with a first voltage and a second AC load associated with a second voltage different from the first voltage.

14. The method of claim 13, wherein providing power to at least one of the first AC load and the second AC load includes:

providing power to at least one of the first AC load and second AC load based on a position of a switch associated with the first AC load and a position of at least one other switch associated with the second AC load.

15. The method of claim 10, wherein the inverter circuit may operate as a rectifier circuit to rectify a second AC signal received from the transformer to provide a DC signal to the low voltage DC bus.

16. The method of claim 1, wherein simultaneously providing power from a shore power source to the AC load, and to the low voltage DC bus and high voltage DC bus through the transformer includes:

providing power from a shore power source to the AC load;

providing power from the shore power source to the transformer; and

simultaneously providing power from the transformer to the high voltage DC bus and the low voltage DC bus.

17. The method of claim 16, wherein providing power to the AC load is performed simultaneously with providing power to the low voltage DC bus and the high voltage DC bus.

18. The method of claim 16, wherein simultaneously providing power from the transformer to the high voltage DC bus and the low voltage DC bus includes:

providing an AC signal received from the shore power source to a pre-regulator to produce a high frequency AC signal;

providing the high frequency AC signal to a low voltage side of the transformer;

rectifying a high voltage high frequency AC signal received from a high voltage side of the transformer to produce a high voltage DC signal; and

rectifying a low voltage high frequency AC signal received from the low voltage side of the transformer to produce a low voltage DC signal.

19. The method of claim 18, wherein rectifying a high voltage high frequency AC signal provided at a high voltage side of the transformer to produce a high voltage DC signal includes:

filtering the high voltage DC signal; and

providing the filtered high voltage DC signal to the high voltage DC bus.

20. The method of claim 18, wherein rectifying a low voltage high frequency AC signal provided at the low voltage side of the transformer to produce a low voltage DC signal includes:

filtering the low voltage DC signal; and

providing the filtered low voltage DC signal to the low voltage DC bus.

21. The method of claim 19, wherein providing the filtered high voltage DC signal to the high voltage DC bus includes:

providing the filtered high voltage DC signal to a chopper circuit; and

controlling power to the high voltage DC bus through the chopper circuit, wherein the chopper circuit may be configured to;

(i) block the high voltage DC signal from being provided to the high voltage DC bus,

(ii) restrict the amount of current associated with the high voltage DC signal provided to the high voltage DC bus, and

(iii) allow the high voltage DC signal to flow to the high voltage DC bus.

22. The method of claim 20, wherein providing the filtered low voltage DC signal to the low voltage DC bus includes:

providing the filtered low voltage DC signal to a chopper circuit; and

controlling power to the low voltage DC bus through the chopper circuit, wherein the chopper circuit may be configured to;

(i) block the low voltage DC signal from being provided to the low voltage DC bus,

(ii) restrict the amount of current associated with the low voltage DC signal provided to the low voltage DC bus, and

(iii) allow the low voltage DC signal to flow to the low voltage DC bus.

23. A system comprising:

a high voltage bus;

a low voltage bus;

a transformer disposed between the high voltage bus and low voltage bus;

a first inverter/rectifier circuit connected between the high voltage bus and a primary side of the transformer;

a second inverter/rectifier circuit interconnected between the low voltage bus and a secondary side of the transformer; and

an AC load connected to a tap positioned on the secondary side of the transformer,

wherein the system is configured to selectively provide power simultaneously to the high voltage bus through the first inverter/rectifier circuit and power to the AC load through the tap, selectively provide power simultaneously to the low voltage bus through the second inverter/rectifier circuit and power to the AC load through the tap, and selectively provide power simultaneously to the AC load from a shore power source and power to the low voltage bus through the second inverter/rectifier circuit and power to the high voltage bus through the first inverter/rectifier circuit.

24. The system of claim 23, wherein the first inverter/rectifier circuit is configured to:

rectify AC signals provided by the transformer to produce DC signals that are provided to the high voltage bus; and

invert DC signals provided from the high voltage bus to produce AC signals that are provided to the primary side of the transformer.

25. The system of claim 23, wherein the second inverter/rectifier circuit is configured to:

rectify AC signals provided by the transformer to produce DC signals that are provided to the low voltage bus; and

invert DC signals provided from the low voltage bus to produce AC signals that are provided to the primary side of the transformer.

26. The system of claim 23, wherein when the system simultaneously provides power to the high voltage bus through the first inverter/rectifier circuit and power to the AC load through the tap, the second inverter/rectifier circuit operates as an inverter to provide AC signals to the transformer from DC signals provided by the low voltage bus, and the first inverter/rectifier circuit operates as a rectifier to produce DC signals from AC signals provided by the transformer on its primary side.

27. The system of claim 26, wherein the AC signals provided to the transformer are sine triangle pulse modulated high frequency AC signals, and the system further includes:

a filter for filtering a high frequency component associated with the DC signals.

28. The system of claim 26, wherein the transformer provides high frequency AC signals to the tap, and the system further includes:

a filter for filtering a high frequency component associated with the high frequency AC signals provided to the tap.

29. The system of claim 23, wherein when the system simultaneously provides power to the low voltage bus through the second inverter/rectifier circuit and power to the AC load through the tap, the first inverter/rectifier circuit operates as an inverter to provide AC signals to the transformer from DC signals provided from the high voltage bus, and the second inverter/rectifier circuit operates as a rectifier to produce DC signals from AC signals provided by the transformer on its secondary side.

30. The system of claim 23, wherein when the system simultaneously provides power to the AC load from a shore power source and power to the low voltage bus through the second inverter/rectifier circuit and power to the high voltage bus through the first inverter/rectifier circuit, the second inverter/rectifier circuit operates as a rectifier to provide high voltage DC signals to the high voltage bus from high voltage AC signals provided by the transformer, and the second inverter/rectifier circuit operates as a rectifier to provide low voltage DC signals to the low voltage bus from low voltage AC signals provided by the transformer.

31. A system for providing multiple power conversion operations, comprising:

a transformer interconnected between a high voltage DC bus and a low voltage DC bus;

an AC load connected to the transformer through an AC power supply line,

wherein the system is configured to selectively;

(i) provide power simultaneously from the low voltage DC bus to the high voltage DC bus and the AC load, through the transformer,

(ii) provide power simultaneously from the high voltage DC bus to the low voltage DC bus and the AC load, through the transformer, and

(iii) provide power simultaneously from a shore power source to the AC load, and, to the low voltage DC bus and high voltage DC bus through the transformer.

32. A system for performing multiple power conversion operations, comprising:

means for simultaneously providing power from a low voltage DC bus to a high voltage DC bus and an AC load through a transformer connected between the high voltage DC bus and the low voltage DC bus;

means for simultaneously providing power from the high voltage DC bus to the low voltage DC bus and the AC load through the transformer; and

means for simultaneously providing power from a shore power source to the AC loads, and to the low voltage DC bus and high voltage DC bus through the transformer.

33. A method performed by a multi-function system including a high voltage DC bus, a low voltage DC bus, and a transformer connected between the high voltage DC bus and the low voltage DC bus, the method comprising:

selectively providing power simultaneously from the low voltage DC bus to the high voltage DC bus and an AC load through the transformer;

selectively providing power simultaneously from the high voltage DC bus to the low voltage DC bus and the AC load through the transformer; and

selectively providing power simultaneously from a shore power source to the AC load, and to the low voltage DC bus and high voltage DC bus through the transformer.