High-voltage power converter
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.
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.
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.
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.
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.
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.
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.