INTERFACE ARRANGEMENT BETWEEN AC AND DC SYSTEMS FOR RELIABLE OPENING OF THE CIRCUIT BREAKER IN TIME

• US 20140268942A1
• Filed: 10/27/2011
• Published: 09/18/2014
• Est. Priority Date: 10/27/2011
• Status: Active Grant

• Current Assignee: Hitachi Energy Limited (Hitachi, Ltd.)
• Original Assignee: ABB Technology AG (ABB Limited)
• Inventors: Jiang Hfner, Ying
• Granted Patent: US 8,971,070 B2
• Time in Patent Office: Days
• US Class Current: 363/53
• CPC Class Codes: H02H 3/023 by short-circuiting
• CPC Class Codes: H02H 7/122 for inverters, i.e. dc/ac converters
• CPC Class Codes: H02H 7/125 for rectifiers
• CPC Class Codes: H02H 7/1255 responsive to internal faults, e.g. by monitoring ripple in output voltage
• CPC Class Codes: H02J 3/36 Arrangements for transfer of electric power between ac networks via a high-tension dc link
• 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

An interface arrangement for coupling between an AC system and a DC system. The arrangement includes a converter for conversion between AC and DC and having a DC side with a first and a second terminal for connection to the DC system and an AC side with a group of terminals for being coupled to the AC system, a transformer having a primary side with a first set of primary windings for being coupled to the AC system and a secondary side with a second set of secondary windings coupled to the converter, where the transformer is equipped with a third set of auxiliary windings and a short-circuiting device is connected between the third set of auxiliary windings and ground.

Claims

1-15. -15. (canceled)

16. Interface arrangement for coupling between an AC system and a DC system and comprising

a converter for conversion between AC and DC, said converter having a DC side with a first and a second terminal for connection to said DC system and an AC side with a group of terminals for being coupled to said AC system,

a transformer having a primary side with a first set of primary windings for being coupled to said AC system and a secondary side with a second set of secondary windings coupled to said converter, said transformer being equipped with a third set of auxiliary windings,

a short-circuiting device connected between said third set of auxiliary windings and ground, and

a fault detecting unit configured to detect a fault on one of the converter terminals and activate the short-circuiting device for short-circuiting the third set of auxiliary windings.

17. The arrangement according to claim 16, wherein the third set of auxiliary windings has fewer turns than the second set of secondary windings.

18. The arrangement according to claim 17, wherein the turns ratio between the second set of secondary windings and the third set of auxiliary windings is at least 10:

1.

19. The arrangement according to claim 16, wherein the short-circuiting device is configured to perform a short-circuiting within 40 ms after being activated.

20. The arrangement according to claim 16, wherein the short-circuiting device is connected to the third set of auxiliary windings in parallel with an auxiliary power supply system.

21. The arrangement according to claim 16, wherein the short-circuiting device is dimensioned to be operable at the voltage levels of the third set of auxiliary windings.

22. The arrangement according to claim 16, wherein the fault detecting unit is configured to detect a pole-to-ground fault on one of the DC terminals.

23. The arrangement according to claim 16, wherein the fault detecting unit is configured to detect a single-phase-to-ground fault on the group of terminals.

24. Arrangement according to claim 22, further comprising a further fault detecting unit configured to detect a single-phase-to ground fault on the group of terminals.

25. The arrangement according to claim 16, further comprising a circuit breaker between the primary side of the transformer and the AC system.

26. The arrangement according to claim 16, wherein the short-circuiting device is a high-speed switch.

27. The arrangement according to claim 16, wherein the short-circuiting device is an active crowbar.

28. The arrangement according to claim 16, wherein the converter is a voltage source converter.

29. The arrangement according to claim 28, wherein the voltage source converter is a cell-based multilevel voltage source converter.

30. The arrangement according to claim 16, wherein the converter is a current source converter.

31. The arrangement according to claim 17, wherein the short-circuiting device is configured to perform a short-circuiting within 40 ms after being activated.

32. The arrangement according to claim 18, wherein the short-circuiting device is configured to perform a short-circuiting within 40 ms after being activated.

33. The arrangement according to claim 17, wherein the short-circuiting device is connected to the third set of auxiliary windings in parallel with an auxiliary power supply system.

34. The arrangement according to claim 18, wherein the short-circuiting device is connected to the third set of auxiliary windings in parallel with an auxiliary power supply system.

35. The arrangement according to claim 19, wherein the short-circuiting device is connected to the third set of auxiliary windings in parallel with an auxiliary power supply system.