Method and system for control power in remote DC power systems

• US 9,450,412 B2
• Filed: 12/22/2010
• Issued: 09/20/2016
• Est. Priority Date: 12/22/2010
• Status: Expired due to Fees

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Schroeder, Stefan, Sihler, Christof Martin, Rosado, Sebastian Pedro
• Primary Examiner(s): Barnie, Rexford
• Assistant Examiner(s): DHILLON, JAGDEEP S
• Application Number:
  US12/976,106
• Publication Number:
  US 20120161518A1
• Time in Patent Office: 2,099 Days
• Field of Search: 307/36, 307 1- 3, 307/125, 307/39, 307/44, 307/80, 307/82, 361/8, 290/40
• US Class Current: 1/1
• CPC Class Codes: H02J 11/00 Circuit arrangements for providing service supply to auxiliaries of stations in which electric power is generated, distributed or converted
• CPC Class Codes: H02J 3/01 Arrangements for reducing harmonics or ripples
• 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

A method and system for a control power supply system is provided. The control power supply system includes a first conductor configured to carry a direct current (DC) electrical current from a source to a load, a second conductor configured to carry the DC electrical current from the load to the source, a electrical device electrically coupled in series with at least one of the first and second conductor. The electrical device is configured to fail in a shorted condition such that failure of the electrical device maintains a direct current (DC) ring bus including the first and second conductor. The control power supply system also includes a control power circuit electrically coupled in parallel with at least a portion of the electrical device such that a DC voltage across at least a portion of the electrical device provides a DC voltage supply to the control power circuit.

Claims

1. A control power supply system comprising:

a first conductor configured to carry a direct current (DC) electrical current from a source to a load;

a second conductor configured to carry the DC electrical current from the load to the source;

an electrical device electrically coupled in series to at least one of said first and second conductor, said electrical device comprising a plurality of diodes coupled in series with at least one of said first conductor and said second conductor, wherein;

each diode of said plurality of diodes coupled in a forward bias direction with respect to a flow of the DC electrical current in said first conductor and said second conductor; and

said electrical device configured to only fail in a shorted condition such that failure of said electrical device maintains a DC ring bus comprising said first conductor and second conductor; and

a control power circuit electrically coupled in parallel with a portion of said electrical device such that a DC voltage across said portion of said electrical device provides a DC voltage supply to said control power circuit.

2. A control power supply system in accordance with claim 1, wherein said electrical device comprises at least one semiconductor device.

3. A control power supply system in accordance with claim 1, wherein said plurality of diodes comprises a press pack housing.

4. A control power supply system in accordance with claim 1, wherein said control power circuit comprises an active switching device to facilitate converting the DC voltage at a first level to a DC voltage at a second level different from the first level.

5. A control power supply system in accordance with claim 1, wherein said control power circuit comprises an active switching device controllable to operate at a voltage less than a forward voltage drop of said portion of said electrical device.

6. A control power supply system in accordance with claim 1, further comprising a capacitive voltage divider configured to supply start-up power to said control power circuit and a second auxiliary power supply configured to supply operating power to said control power circuit.

7. A control power supply system in accordance with claim 6, wherein said second auxiliary power supply is configured to harvest AC ripple from a switched DC converter.

8. A method of supplying control power supply from a direct current (DC) power cable, said method comprising:

transmitting a DC power current from a sending station to a load station located remotely from the sending station through a DC power cable;

dropping a DC voltage across one or more electrical devices, wherein the one or more electrical devices includes a plurality of diodes coupled in electrical series with the sending station and the load station through the DC power cable, the plurality of diodes further coupled in a forward bias direction with respect to a direction of flow of the DC power current through the DC power cable; and

generating a control power voltage using an active semiconductor switch coupled in electrical parallel with the one or more electrical devices.

9. A method in accordance with claim 8, further comprising:

filtering an AC ripple voltage from the DC power cable, the AC ripple voltage induced onto the DC power cable by a switching action of a plurality of electrical devices; and

transmitting the filtered AC ripple voltage to the control power supply.

10. A method in accordance with claim 8, further comprising supplying a startup power to the AC control power supply using a capacitive voltage divider.