PLANT FOR TRANSMITTING ELECTRIC POWER

• US 20110080758A1
• Filed: 06/10/2008
• Published: 04/07/2011
• Est. Priority Date: 06/10/2008
• Status: Abandoned Application

• Current Assignee: ABB Technology AG (ABB Limited)
• Original Assignee: ABB Technology AG (ABB Limited)
• Inventors: Asplund, Gunnar
• Application Number:
  US12/997,160
• Publication Number:
  US 20110080758A1
• Time in Patent Office: Days
• US Class Current: 363/35
• CPC Class Codes: H02J 3/36 Arrangements for transfer of electric power between ac networks via a high-tension dc link
• CPC Class Codes: H02M 5/4505 having a rectifier with controlled elements
• CPC Class Codes: H02M 5/458 using semiconductor devices only
• 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 7/797 using semiconductor devices only
• CPC Class Codes: Y02E 60/60 Arrangements for transfer of electric power between AC networks or generators via a high voltage DC link [HVCD]

Abstract

A plant for transmitting electric power comprises a direct voltage network for High Voltage Direct Current and at least one alternating voltage network connected thereto through a station. The station comprises at least one Voltage Source Converter adapted to convert direct voltage into alternating voltage and conversely. In the direct voltage network at least one parallel connection of at least one semiconductor device of turn-off type and a resistor is connected in series with a direct voltage line of the direct voltage network.

Claims

1-10. -10. (canceled)

11. A plant for transmitting electric power comprising a direct voltage network for High Voltage Direct Current and at least one alternating voltage network connected thereto through a station, in which the station is configured to perform transmitting of electric power between the direct voltage network and the alternating voltage network and comprises at least one Voltage Source Converter connected to a first and a second direct voltage line of the direct voltage network and adapted to convert direct voltage into alternating voltage and conversely, each direct voltage line connected to said Voltage Source Converter being further connected in series with a corresponding parallel element combination for limiting a fault current in case of a dc-side short circuit, each parallel element combination comprising at least one semiconductor device of turn-off type, said plant also comprising an apparatus adapted to turn said at least one semiconductor device of said parallel element combinations off when the current therethrough exceeds a predetermined level and, when the current in the direct voltage network exceeds a predetermined level, to start to alternatingly turn said at least one semiconductor device of said parallel element combinations off and on with a frequency in the kHZ range adapted for adjusting the current in the direct voltage network to not exceed a maximum level, wherein each parallel element combination comprises a resistor in parallel with the semiconductor device.

12. The plant according to claim 11, wherein the resistance of the resistor at room temperature is 10 Ω

-100 Ω

.

13. The plant according to claim 11, wherein the element combination comprises a surge diverter connected in parallel with said semiconductor device and resistor.

14. The plant according to claim 13, wherein the voltage rating of said surge diverter is lower than the voltage blocking capacity of said at least one semiconductor device of said parallel element combination.

15. The plant according to claim 11, wherein said apparatus is adapted to carry out turning on and turning off of said at least one semiconductor device with a frequency in the region of the frequency by which semiconductor devices of said Voltage Source Converter are turned on and turned off.

16. The plant according to claim 11, wherein at least one semiconductor device of turn-off type is an IGBT (Insulated Gate Bipolar Transistor), an IGCT (Integrated Gate Commutated Thyristor) or a GTO (Gate Turn-Off Thyristor).

17. The plant according to claim 11, wherein it is configured to have a direct voltage across poles of said direct voltage network being 1 kV to 1200 kV, 10 kV to 1200 kV or 100 kV to 1200 kV.

18. The plant according to claim 11, wherein at least one Voltage Source Converter of said station is of the type having at least one phase leg, which connects to opposite poles of a direct voltage side of the converter and comprises a series connection of switching cells, each said switching cell having on one hand at least two semiconductor assemblies having each a semiconductor device of turn-off type and a free-wheeling diode connected in anti-parallel therewith and on the other at least one energy storing capacitor, a mid point of said series connection forming a phase output being configured to be connected to an alternating voltage side of the converter, each said switching cell being configured to obtain two switching states by control of said semiconductor devices of each switching cell, namely a first switching state and a second switching state, in which the voltage across said at least one energy storing capacitor and a zero voltage, respectively, is applied across the terminals of the switching cell, for obtaining a determined alternating voltage on said phase output.

19. The plant according to claim 12, wherein the element combination comprises a surge diverter connected in parallel with said semiconductor device and resistor.

20. The plant according to claim 12, wherein said apparatus is adapted to carry out turning on and turning off of said at least one semiconductor device with a frequency in the region of the frequency by which semiconductor devices of said Voltage Source Converter are turned on and turned off.

21. The plant according to claim 13, wherein said apparatus is adapted to carry out turning on and turning off of said at least one semiconductor device with a frequency in the region of the frequency by which semiconductor devices of said Voltage Source Converter are turned on and turned off.

22. The plant according to claim 14, wherein said apparatus is adapted to carry out turning on and turning off of said at least one semiconductor device with a frequency in the region of the frequency by which semiconductor devices of said Voltage Source Converter are turned on and turned off.

23. The plant according to claim 12, wherein at least one semiconductor device of turn-off type is an IGBT (Insulated Gate Bipolar Transistor), an IGCT (Integrated Gate Commutated Thyristor) or a GTO (Gate Turn-Off Thyristor).

27. The plant according to claim 12, wherein it is configured to have a direct voltage across poles of said direct voltage network being 1 kV to 1200 kV, 10 kV to 1200 kV or 100 kV to 1200 kV.

28. The plant according to claim 13, wherein it is configured to have a direct voltage across poles of said direct voltage network being 1 kV to 1200 kV, 10 kV to 1200 kV or 100 kV to 1200 kV.

29. The plant according to claim 14, wherein it is configured to have a direct voltage across poles of said direct voltage network being 1 kV to 1200 kV, 10 kV to 1200 kV or 100 kV to 1200 kV.

30. The plant according to claim 11, wherein the resistance of the resistor at room temperature is 20 Ω

-50 Ω

.

24. The plant according to clam 13, wherein at least one semiconductor device of turn-off type is an IGBT (Insulated Gate Bipolar Transistor), an IGCT (Integrated Gate Commutated Thyristor) or a GTO (Gate Turn-Off Thyristor).

25. The plant according to clam 14, wherein at least one semiconductor device of turn-off type is an IGBT (Insulated Gate Bipolar Transistor), an IGCT (Integrated Gate Commutated Thyristor) or a GTO (Gate Turn-Off Thyristor).

26. The plant according to clam 15, wherein at least one semiconductor device of turn-off type is an IGBT (Insulated Gate Bipolar Transistor), an IGCT (Integrated Gate Commutated Thyristor) or a GTO (Gate Turn-Off Thyristor).