Breaker design for power system resiliency

Patent metadata

Field	Value
Publication number	US-9825457-B2
Application number	US-201414210346-A
Country	US
Kind code	B2
Filing date	Mar 13, 2014
Priority date	Mar 13, 2013
Publication date	Nov 21, 2017
Grant date	Nov 21, 2017

Abstract

An autonomous breaker can apply a current through a high impedance source to a bus coupled to either end of a breaker in order to measure an impedance of the bus. The status of the bus can be determined from the measurement. Based on the determined status, a fault detection procedure can be selected and implemented to determine if a fault exists on the bus. When the fault detection procedure has been implemented and no fault has been detected, the breaker can close, and thus couple the bus to another bus.

First claim

What is claimed is:

1. A method, comprising:
energizing a first bus with a first AC power source;
energizing a second bus with a second AC power source;
applying, by a tie breaker system, a first current to the first energized bus coupled to a breaker between the first bus and the second bus while the breaker is open;
measuring, by the tie breaker system, a first impedance of the first energized bus after applying the first current to the first energized bus;
determining, by the tie breaker system, if a fault exists on the first energized bus based, at least in part, on the measured first impedance; and
coupling, by the tie breaker system, the first energized bus to the second energized bus when no fault exists on the first energized bus by synchronizing AC energy on the first energized bus with AC energy on the second energized bus and closing the breaker between the first energized bus and the second energized bus, wherein the step of synchronizing AC energy comprises providing signals to at least one of the first power source energizing the first energized bus and the second power source energizing the second energized bus.

2. The method of claim 1 , wherein applying a first current to a first bus comprises applying the first current through a transformer to the first bus.

3. The method of claim 1 , further comprising:
receiving a command, at a controller, to close the breaker before applying the first current; and
instructing, by a controller, a contactor to close or open after measuring a first impedance.

4. The method of claim 1 , wherein determining if a fault exists on the first bus comprises:
determining a fault detection procedure to implement based, in part, on the measured first impedance of the first bus; and
implementing the selected fault detection procedure.

5. The method of claim 1 , wherein applying the first current comprises applying the first current at a first frequency, and the method further comprising:
applying a second current at a second frequency; and
measuring a second impedance of the first bus after applying the second current to the first bus, wherein the step of determining if a fault exists on the bus comprises determining if a fault exists based, at least in part, on the measured first impedance and the measured second impedance.

6. The method of claim 1 , wherein the breaker comprises a tie breaker and the step of coupling the first bus to the second bus comprises coupling a generator to a load on a drilling vessel.

7. The method of claim 4 , wherein determining a fault detection procedure comprises:
processing the measured first impedance;
determining the status of the first bus after processing the measured impedance; and
selecting the fault detection procedure to implement based, in part, on the determined status of the first bus.

8. The method of claim 4 , wherein implementing the selected fault detection procedure comprises:
instructing a contactor to close or open;
applying a second current to the first bus;
measuring a second impedance of the first bus after applying the second current; and
determining whether a fault exists on the first bus based, in part, on the second impedance.

9. An apparatus, comprising:
a breaker coupled between a first bus and a second bus, wherein the first bus is energized with AC energy from a first AC power source and the second bus is energized with AC energy from a second AC power source;
a controller coupled to the breaker;
a synchronizer coupled to the first energized bus and an external power source on the second bus, wherein the synchronizer is configured to synchronize AC energy on the second energized bus with AC energy on the first energized bus, wherein the synchronizer is configured to provide signals to at least one of the first power source energizing the first energized bus and the second power source energizing the second energized bus to synchronize AC energy between the first energized bus and the second energized bus;
a first potential transformer coupled to a controller and the first bus; and
a second potential transformer coupled to the controller and the second bus, in which the controller is configured:
to apply a first current from the second energized bus to the first energized bus while the breaker is open;
to measure a first impedance of the first energized bus after applying the first current to the first energized bus;
to determine if a fault exists on the first bus based, at least in part, on the measured first impedance; and
when no fault is determined to exist, to activate the breaker and the synchronizer to synchronize and to couple the first energized bus to the second energized bus to supply AC energy from the second energized bus to the first energized bus.

10. The apparatus of claim 9 , in which the first potential transformer comprises a primary transformer and secondary transformers in a broken delta configuration.

11. The apparatus of claim 9 , further comprising:
a sensor for monitoring either a voltage, current, or both the voltage and current;
a first contactor coupled between the sensor and the first potential transformer; and
a second contactor coupled between the sensor and a second potential transformer.

12. The apparatus of claim 9 , further comprising a first fault sensor coupled to the first potential transformer and the controller and a second fault sensor coupled to the second potential transformer and the controller.

13. The apparatus of claim 9 , further comprising a first relay coupled to the first potential transformer and the controller and a second relay coupled to the second potential transformer and the controller.

14. The apparatus of claim 9 , further comprising an operator interface coupled to the controller, in which the controller is further configured to manage control commands received from the operator interface.

15. The apparatus of claim 14 , wherein the controller is further configured:
to apply a second current at a second frequency;
to measuring a second impedance of the first bus after applying the second current to the first bus; and
to determine if a fault exists on the bus based, at least in part, on the measured first impedance and the measured second impedance.

16. The apparatus of claim 14 , in which the operator interface comprises:
a sync and close switch to initiate the synchronizing of the external power source;
a sync and close cancel switch to cancel the synchronizing of the external power source;
a sync potentiometer to bias the external power source; and
a synchroscope to display the phase difference between unsynchronized sources.

17. An apparatus, comprising:
a breaker coupled to a first energized bus energized with AC energy from a first AC power source and a second energized bus energized with AC energy from a second AC power source;
means for applying a first current to the first energized bus; and
a controller coupled to the first current applying means, in which the controller is configured:
to determine if a fault exists on the first energized bus while the breaker is open; and
to couple the first energized bus to the second energized bus through the breaker when no fault exists on the first bus by synchronizing AC energy on the first energized bus with AC energy on the second energized bus and closing the breaker between the first energized bus and the second energized bus, wherein the step of synchronizing AC energy comprises providing signals to at least one of the first power source energizing the first energized bus and the second power source e

Assignees

• Transocean Sedco Forex Ventures Ltd
• Aspin Kemp & Ass Holding Corp
• Aspin Kemp & Ass

Inventors

• Bourgeau Edward Peter Kenneth
• Aspin Jason

Classifications

• H02H3/00

  Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection (specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems H02H7/00; systems for change-over to standby supply H02J9/00 ){; integrated protection (for motors H02H7/0822)} · CPC title

• H02H7/28

  for meshed systems · CPC title

• H02H3/04

  with warning or supervision in addition to disconnection, e.g. for indicating that protective apparatus has functioned {(watching of pilot wires H02H1/0084; protection of protective arrangements H02H7/008; indication of the state of electronic switches H03K17/18)} · CPC title

• H02H3/066

  Reconnection being a consequence of eliminating the fault which caused disconnection · CPC title

• H02J13/0006

  Electricity · mapped topic