High-voltage power converter

• US 9,374,014 B2
• Filed: 11/27/2012
• Issued: 06/21/2016
• Est. Priority Date: 05/27/2010
• Status: Active Grant

• Current Assignee: Vestas Wind Systems A/S
• Original Assignee: Vestas Wind Systems A/S
• Inventors: Kjr, Philip Carne
• Primary Examiner(s): Fureman, Jared
• Assistant Examiner(s): Pham, Duc M
• Application Number:
  US13/686,579
• Publication Number:
  US 20130181532A1
• Time in Patent Office: 1,302 Days
• Field of Search: 307/77
• US Class Current: 1/1
• CPC Class Codes: H02M 1/34 Snubber circuits
• CPC Class Codes: H02M 1/342 Active non-dissipative snubbers
• CPC Class Codes: H02M 5/4585 having a rectifier with controlled elements
• CPC Class Codes: H02M 7/4835 comprising two or more cells, each including a switchable capacitor, the capacitors having a nominal charge voltage which corresponds to a given fraction of the input voltage, and the capacitors being selectively connected in series to determine the instantaneous output voltage
• CPC Class Codes: H02M 7/4837 Flying capacitor converters
• CPC Class Codes: H02M 7/487 Neutral point clamped inverters
• CPC Class Codes: H02M 7/523 with LC-resonance circuit in the main circuit
• CPC Class Codes: H02M 7/5387 in a bridge configuration
• 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

The present invention relates to a high-voltage power converter comprising a number of controllable switching valves, each switching valve comprising a plurality of series connected switching units, the high-voltage power converter further comprising a resonance circuit comprising a link inductor and a link capacitor, and a plurality of clamping circuits connected in series, each clamping circuit comprising a clamping capacitor and a clamping switching unit.

Claims

1. A high-voltage power converter comprising:

a direct current (DC) link;

one or more controllable switching valves, each switching valve comprising a plurality of series-connected switching units;

a plurality of series-connected clamping circuits connected between the DC link and the one or more controllable switching valves, each clamping circuit comprising a respective clamping capacitor, a respective link inductor and a respective clamping switching unit; and

a resonance circuit coupled with the DC link and with the one or more controllable switching valves, the resonance circuit comprising a resonant link inductor and a link capacitor, wherein the resonant link inductor is formed using a series connection of the link inductors of the plurality of series-connected clamping circuits.

2. A high-voltage power converter according to claim 1, wherein the power converter is adapted to generate power voltage levels between 10 and 50 kV.

3. A high-voltage power converter according to claim 1, wherein at least one of the series-connected switching units comprises a transistor and a diode coupled in an anti-parallel connection.

4. A high-voltage power converter according to claim 1, wherein at least one of the series-connected switching units comprises a thyristor and a diode coupled in an anti-parallel connection.

5. A high-voltage power converter according to claim 1, wherein the one or more switching valves comprises series-connected first and second switching units, wherein the first switching unit comprises a transistor and a diode coupled in an anti-parallel connection, and wherein the second switching unit comprises a thyristor and a diode coupled in an anti-parallel connection.

6. A high-voltage power converter according to claim 1, wherein the link capacitor is formed by a plurality of distributed link capacitors.

7. A high-voltage power converter according to claim 6, wherein at least one of the series-connected switching units comprises one of the plurality of distributed link capacitors.

8. A high-voltage power converter according to claim 7 wherein each of the series-connected switching units comprises a respective one of the plurality of distributed link capacitors.

9. A high-voltage power converter according to claim 1, further comprising a plurality of series-connected energy dissipating circuits.

10. A high-voltage power converter according to claim 9, wherein each of the series-connected energy dissipating circuits comprises a chopper switch and a dump load.

13. A high-voltage power converter according to claim 1, wherein each clamping circuit comprises the link inductor in parallel with a series connection of the clamp capacitor and the clamp switching unit, wherein the clamp switching unit comprises a semiconductor power transistor with an anti-parallel connected diode.

14. A high-voltage power converter according to claim 1, wherein the clamp switching units corresponding to the plurality of series-connected clamping unit circuits are arranged to be operated independently of each other.

11. A high-voltage wind turbine generator comprising a high-voltage power converter comprising:

a direct current (DC) link;

one or more controllable switching valves, each switching valve comprising a plurality of series-connected switching units;

a plurality of series-connected clamping circuits connected between the DC link and the one or more controllable switching valves, each clamping circuit comprising a respective clamping capacitor, a respective link inductor and a respective clamping switching unit; and

a resonance circuit coupled with the DC link and with the one or more controllable switching valves, the resonance circuit comprising a resonant link inductor and a link capacitor, wherein the resonant link inductor is formed using a series connection of the link inductors of the plurality of series-connected clamping circuits.

15. A high-voltage wind turbine generator according to claim 11, wherein the high-voltage power converter further comprises a plurality of series-connected energy dissipating circuits.

16. A high-voltage wind turbine generator according to claim 15, wherein each of the series-connected energy dissipating circuits comprises a chopper switch and a dump load.

12. A wind power plant comprising a plurality of high-voltage wind turbine generators, each high-voltage wind turbine generator comprising a high-voltage power converter comprising:

a direct current (DC) link;

one or more controllable switching valves, each switching valve comprising a plurality of series-connected switching units;

a plurality of series-connected clamping circuits connected between the DC link and the one or more controllable switching valves, each clamping circuit comprising a respective clamping capacitor, a respective link inductor and a respective clamping switching unit; and

a resonance circuit coupled with the DC link and with the one or more controllable switching valves, the resonance circuit comprising a resonant link inductor and a link capacitor, wherein the resonant link inductor is formed using a series connection of the link inductors of the plurality of series-connected clamping circuits.

17. A wind power plant according to claim 12, wherein the high-voltage power converters further comprise a plurality of series-connected energy dissipating circuits.

18. A wind power plant according to claim 17, wherein each of the series-connected energy dissipating circuits comprises a chopper switch and a dump load.