HIGH VOLTAGE DC BREAKER APPARATUS

• US 20130038975A1
• Filed: 05/11/2010
• Published: 02/14/2013
• Est. Priority Date: 05/11/2010
• Status: Active Grant

• Current Assignee: Hitachi Energy Limited (Hitachi, Ltd.)
• Original Assignee: ABB Technology AG (ABB Limited)
• Inventors: Asplund, Gunnar, Hfner, Jurgen
• Granted Patent: US 9,208,979 B2
• Time in Patent Office: Days
• US Class Current: 361/93.9
• CPC Class Codes: H01H 2009/543 third parallel branch comprising an energy absorber, e.g. MOV, PTC, Zener
• CPC Class Codes: H01H 2009/544 the static switching means being an insulated gate bipolar transistor, e.g. IGBT, Darlington configuration of FET and bipolar transistor
• CPC Class Codes: H01H 33/596 for interrupting dc
• CPC Class Codes: H01H 9/548 Electromechanical and static switch connected in series
• CPC Class Codes: H02H 3/025 Disconnection after limiting, e.g. when limiting is not sufficient or for facilitating disconnection
• CPC Class Codes: H02H 3/08 responsive to excess current responsive to abnormal temperature caused by excess current H02H5/04
• CPC Class Codes: H02H 9/025 Current limitation using field effect transistors
• 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 high voltage DC breaker apparatus configured to break a fault current occurring in a high voltage DC conductor includes a current limiting arrangement having at least one section with at least one semiconductor device of turn-off type and at least one arrester connected in parallel therewith, and a mechanical DC breaker connected in series with the current limiting arrangement and including a mechanical switch. The mechanical DC breaker is configured to enable breaking of a fault current in said DC conductor once said semiconductor devices of said arrangement have been turned off.

Claims

1. A high voltage DC breaker apparatus configured to break a fault current occurring in a high voltage DC conductor, said apparatus comprising

a current limiting arrangement having at least one section with at least one semiconductor device of turn-off type and at least one arrester connected in parallel therewith, said at least one section is connected in series with said DC conductor,

means configured to detect occurrence of a fault current in said DC conductor, and

a unit configured to control breaking of said fault current upon detection of occurrence thereof, said control including turning off all semiconductor devices of said arrangement,

wherein the apparatus further comprises a mechanical DC breaker connected in series with said current limiting arrangement and including a mechanical switch, and that said mechanical DC breaker is configured to enable breaking of a fault current in said DC conductor once said semiconductor devices of said arrangement have been turned off.

2. An apparatus according to claim 1, wherein the protective voltage level of said arrangement defined by said at least one arrester is a DC voltage intended for a said DC conductor with respect to ground ±

10%.

3. An apparatus according to claim 1, wherein each said at least one section has a plurality of said semiconductor devices connected in series and jointly controllable through said control unit.

4. An apparatus according to claim 1, wherein said arrangement comprises a plurality of said sections individually controllable by said control unit by controlling said at least one semiconductor device thereof.

5. An apparatus according to claim 1, wherein said mechanical DC breaker comprises, connected in parallel with said mechanical switch, at least one module having at least one semiconductor device of turn-off type and at least one arrester connected in parallel therewith, and that said control unit is configured to control breaking of a said fault current by controlling the mechanical DC breaker in the following order:

turning on the semiconductor devices of said at least one module, opening said mechanical switch for commutating the fault current to flow through the semiconductor devices last mentioned and turning these semiconductor devices off.

6. An apparatus according to claim 5, wherein the protective voltage level of the arrester of said at least one module of the mechanical DC breaker is 30-80% of the DC voltage intended for a said DC conductor with respect to ground.

7. An apparatus according to claim 5, wherein said at least one module of said mechanical DC breaker has a plurality of semiconductor devices connected in series and jointly controllable through said control unit.

8. An apparatus according to claim 5, wherein said mechanical DC breaker comprises a plurality of said modules.

9. An apparatus according to claim 1, wherein said mechanical DC breaker has a series connection of an inductance and a capacitance connected in parallel with said mechanical switch, and that the control unit is configured to control breaking of said fault current by opening said mechanical switch.

10. An apparatus according to claim 1, wherein said at least one section of said current limiting arrangement has a resistor connected in parallel with each arrester of said arrangement, and that the protective voltage level of said mechanical DC breaker is 100%-200% of the DC voltage intended for a said DC conductor.

11. An apparatus according to claim 1, wherein said semiconductor device/devices is/are an IGBT/IGBT:

s, a GTO/GTO;

s or an IGCT/IGCT;

s.

12. An apparatus according to claim 1, wherein it is configured to break a fault current occurring in a high voltage DC conductor intended to be on a voltage level of ≧

10 kV, 10 kV-1000 kV, 100 kV-1000 kV or 300 kV-1000 kV with respect to ground.

13. An apparatus according to claim 1, wherein it is configured to be connected to a said high voltage DC conductor in an AC/DC converter station.

14. An apparatus according to claim 1, wherein it is configured to be arranged in a DC grid for protecting equipment connected thereto.

15. A plant for transmitting electric power through High Voltage Direct Current, wherein it is provided with a DC breaker apparatus according to claim 1.

16. A method for controlling a high voltage DC breaker apparatus according to claim 1 so as to break a fault current detected in said high voltage DC conductor, wherein it comprises the steps:

a) turning the semiconductor devices of said current limiting arrangement off, and

b) controlling said mechanical DC breaker to break the fault current.

17. A method according to claim 16, wherein it is applied on an apparatus in which said mechanical DC breaker comprises, connected in parallel with said mechanical switch, at least one module having at least one semiconductor device of turn-off type and at least one arrester connected in parallel therewith,

and that step b) includes the following sub steps:

c) turning the semiconductor devices of said at least one module of the mechanical DC breaker on,

d) opening said mechanical switch for commutating the current flowing through said mechanical switch to flow through said semiconductor devices last mentioned, and

e) turning said semiconductor devices of said module of the mechanical DC breaker off for breaking said fault current.

18. An apparatus according to claim 2, wherein each said at least one section has a plurality of said semiconductor devices connected in series and jointly controllable through said control unit.

19. An apparatus according to claim 2, wherein said arrangement comprises a plurality of said sections individually controllable by said control unit by controlling said at least one semiconductor device thereof.

20. An apparatus according to claim 3, wherein said arrangement comprises a plurality of said sections individually controllable by said control unit by controlling said at least one semiconductor device thereof.