Multilevel converters for intelligent high-voltage transformers

• US 20070223258A1
• Filed: 02/08/2007
• Published: 09/27/2007
• Est. Priority Date: 11/25/2003
• Status: Abandoned Application

• Current Assignee: Electric Power Research Institute Incorporated
• Original Assignee: Electric Power Research Institute Incorporated
• Inventors: Lai, Jih-Sheng, Maitra, Arindam, Goodman, Frank
• Application Number:
  US11/705,081
• Publication Number:
  US 20070223258A1
• Time in Patent Office: Days
• US Class Current: 363/37
• CPC Class Codes: H02J 3/01 Arrangements for reducing harmonics or ripples
• CPC Class Codes: H02J 3/32 using batteries with converting means
• CPC Class Codes: H02M 5/293 using semiconductor devices only
• CPC Class Codes: H02M 5/4585 having a rectifier with controlled elements
• CPC Class Codes: H02M 7/487 Neutral point clamped inverters
• CPC Class Codes: H02M 7/797 using semiconductor devices only
• CPC Class Codes: Y02E 40/40 Arrangements for reducing harmonics

Abstract

A power conversion device includes a switched AC-to-DC converter circuit coupled to a device input and a switched DC-to-AC converter circuit coupled to the switched AC-to-DC converter circuit and a device output. The switched AC-to-DC converter circuit and the switched DC-to-AC converter circuit are configurable for multi-level step-up and/or step-down conversion.

Claims

1. A power conversion device, comprising:

a switched AC-to-DC converter circuit coupled to a device input; and

a switched DC-to-AC converter circuit coupled to the switched AC-to-DC converter circuit and a device output,

wherein the switched AC-to-DC converter circuit and the switched DC-to-AC converter circuit are configurable for multi-level step-up or step-down conversion.

2. The device of claim 1, wherein the switched AC-to-DC converter circuit is configured to output a DC voltage that is larger than a peak voltage of signals at the device input.

3. The device of claim 1, further comprising a filter coupled to the device input, wherein the filter is configured to provide substantially sinusoidal input signals.

4. The device of claim 1, wherein switched DC-to-AC converter circuit is configured to utilize duty-cycle modulation.

5. The device of claim 1, further comprising a filter coupled to the device output, wherein the filter is configured to provide substantially sinusoidal output signals.

6. The device of claim 5, wherein the switched DC-to-AC converter circuit is configured such that signals between the switched DC-to-AC converter circuit and the filter are pulse-width modulated.

7. The device of claim 1, further comprising an energy storage device coupled between the switched AC-to-DC converter circuit and the switched DC-to-AC converter circuit to mitigate voltage disturbances.

8. The device of claim 7, wherein the energy storage device includes a number of storage devices equal to a number of conversion levels for signals at the device input and the device output.

9. The device of claim 1, wherein the switched AC-to-DC converter circuit and the switched DC-to-AC converter circuit have 11 conversion levels.

10. The device of claim 1, wherein the switched AC-to-DC converter circuit may be configured to adjust a first number of conversion levels of signals at the device input and the switched DC-to-AC converter circuit may be configured to adjust a second number of conversion levels of signals at the device output.

11. The device of claim 1, wherein the switched AC-to-DC converter circuit includes a first plurality of configurable semiconductor switches and the switched DC-to-AC converter circuit includes a second plurality of configurable semiconductor switches.

12. The device of claim 11, wherein the first plurality of configurable semiconductor switches and the second plurality of configurable semiconductor switches include silicon insulated-gate bipolar transistors (IGBT).

13. The device of claim 11, wherein a first number of configurable semiconductor switches in the first plurality of configurable semiconductor switches is selected based on a voltage level of signals at the device input and a voltage limit of the first plurality configurable semiconductor switches, and a second number of configurable semiconductor switches in the second plurality of configurable semiconductor switches is selected based on a voltage level of signals at the device output and a voltage limit of the second plurality configurable semiconductor switches.

14. The device of claim 11, wherein a first number of configurable semiconductor switches in the first plurality of configurable semiconductor switches is selected from a group consisting of 2(N₁−

1), 4(N₁−

1), and 6(N₁−

1), where N₁ is a number of conversion levels of the signals at the device input, and wherein a second number of configurable semiconductor switches in the second plurality of configurable semiconductor switches is selected from a group consisting of 2(N_O−

1), 4(N_O−

1), and 6(N_O−

1), where N_O is a number of conversion levels of the signals at the device output.

15. The device of claim 1, wherein the switched AC-to-DC converter circuit is configured to receive signals having a voltage level of substantially 345 kV and the switched DC-to-AC converter circuit is configured to receive signals having a voltage level of substantially 220 kV.

16. The device of claim 1, wherein the device is configurable for bidirectional power flow.

17. The device of claim 1, wherein a frequency of signals at the device output is configurable.

18. The device of claim 1, wherein the switched AC-to-DC converter circuit is configurable to receive signals at the device input having 3-phases separated by substantially 120°

.

19. The device of claim 1, wherein the switched DC-to-AC converter circuit is configurable to output signals at the device output having 3-phases separated by substantially 120°

.

20. The device of claim 1, wherein the switched AC-to-DC converter circuit is configured to receive signals at the device input having 3-phases separated by substantially 120°

.

21. The device of claim 1, wherein the switched DC-to-AC converter circuit is configured to output signals at the device output having 3-phases separated by substantially 120°

.