Breaker control units and related systems and methods

Patent metadata

Field	Value
Publication number	US-12316112-B2
Application number	US-202217812041-A
Country	US
Kind code	B2
Filing date	Jul 12, 2022
Priority date	Jul 12, 2022
Publication date	May 27, 2025
Grant date	May 27, 2025

Abstract

Breaker control units (BCUs) may include an output to selectively cause a circuit breaker (CB) to open and close a circuit, a voltage input to monitor a voltage of at least one of a bus and a line, a processor to calculate a point-on-wave switching time, and a remote input configured to be coupled to a remote intelligent electronic device (IED) to receive commands to selectively open and close the CB at a specified optimal time. Electric power systems may include such BCUs. Methods of switching CBs may include monitoring at least one of a bus and a line with a BCU and controlling switching of the CB at a predetermined point-on-wave value with onboard electronics of the BCU. The methods may additionally include calculating a trapped charge and/or a residual flux with an IED and causing the BCU to switch the CB at a specific optimum point-on-wave value.

First claim

What is claimed is:

1. A distributed supervisory system to monitor an electric power system, the distributed supervisory system comprising:
a breaker control unit (BCU) configured, the BCU comprising:
a circuit breaker (CB) output;
an electrical parameter interface to monitor at least one electrical parameter of the electric power system;
a remote input;
wherein the BCU is configured:
to be located in a breaker cabinet, and
to coordinate switching of the CB through the CB output to correspond to a predetermined point-on-wave value at a time of switching based on a signal received via the remote input; and

an intelligent electronic device (IED) configured to communicate with the BCU via the remote input, the IED configured:
to calculate an estimate of at least one of trapped charge and residual flux,
generate the signal to cause the CB to switch at a specific point-on-wave value,
transmit the signal to the BCU via the remote input.

2. The distributed supervisory system of claim 1 , wherein the IED is further configured to monitor equipment of the electric power system.

3. The distributed supervisory system of claim 2 , wherein the IED is further configured to monitor at least one additional piece of equipment in the electric power system.

4. The distributed supervisory system of claim 1 , wherein the BCU is further configured to operate independently of the IED upon loss of communication between the IED and BCU to monitor the at least one of a bus and a line and to coordinate the switching of the CB to correspond to the predetermined point-on-wave value at the time of switching.

5. The distributed supervisory system of claim 1 , wherein the IED is configured to provide overriding instructions to the BCU to control the switching of the CB.

6. The distributed supervisory system of claim 1 , wherein the IED is configured to monitor voltage measurements of a transformer to determine a residual flux value of the transformer.

7. The distributed supervisory system of claim 6 , wherein the IED is configured to send a signal to the BCU to connect the transformer to the electric power system based at least in part on the calculated residual flux value and system voltage measurement prior to closing.

8. The distributed supervisory system of claim 1 , further comprising a current input configured to be coupled to a current transformer to monitor a current of at least one of a bus and a line of an electric power system.

9. The distributed supervisory system of claim 1 , further comprising a temperature input configured to receive temperature data relating to a temperature within the circuit breaker cabinet.

10. The distributed supervisory system of claim 1 , further comprising a pressure input configured to receive pressure data relating to a pressure within the circuit breaker cabinet.

11. The distributed supervisory system of claim 1 , wherein the breaker control unit is configured to perform point-on-wave switching of the CB without being coupled to or receiving any commands from an IED.

12. The distributed supervisory system of claim 1 , wherein the IED is remotely located from the BCU and the breaker cabinet.

13. A distributed supervisory system to monitor an electric power system, the distributed supervisory system comprising:
a breaker control unit (BCU) configured, the BCU comprising:
a circuit breaker (CB) output;
an electrical parameter interface to monitor at least one electrical parameter of the electric power system;
a remote input;
wherein the BCU is configured:
to be located in a breaker cabinet, and
to coordinate switching of the CB through the CB output to correspond to a predetermined point-on-wave value at a time of switching based on a signal received via the remote input; and

an intelligent electronic device (IED) configured to communicate with the BCU via the remote input, the IED configured:
to calculate an estimate of an amount of trapped charge of a power line based on voltage measurements of the power line and instruct the BCU to switch the CB at a time corresponding to a point-on-wave associated with the amount of trapped charge,
generate the signal to cause the CB to switch at a specific point-on-wave value,
transmit the signal to the BCU via the remote input.

14. A method of switching circuit breakers using a distributed supervisory system in an electric power system, the method comprising:
monitoring at least one of a bus and a line with a breaker control unit (BCU) located in a breaker cabinet and located proximate to a circuit breaker (CB);
controlling switching of the CB to correspond to a predetermined point-on-wave value at a time of switching with onboard electronics of the BCU; and
calculating an estimate of at least one of trapped charge and residual flux with an intelligent electronic device (IED) and causing the BCU to switch the CB at a specific point-on-wave value at the time of switching with the IED.

15. The method of claim 14 , further comprising monitoring equipment of an electric power system with the IED.

16. The method of claim 15 , further comprising monitoring at least one additional piece of equipment in the electric power system with the IED.

17. The method of claim 14 , further comprising calculating an amount of trapped charge of a power line based on voltage measurements of the power line with the IED and instructing the BCU to switch the CB at a time corresponding to a point-on-wave associated with the amount of trapped charge with the IED.

18. The method of claim 14 , further comprising monitoring voltage measurements of a transformer with the IED and determining a residual flux value of the transformer with the IED.

19. The method of claim 18 , further comprising sending a signal from the IED to the BCU to connect the transformer to the electric power system by switching the CB based at least in part on the calculated residual flux value and system voltage magnitude prior to closing.

Assignees

• Schweitzer Engineering Lab Inc

Inventors

• Chowdhury Ritwik
• Finney Dale S
• Fischer Normann

Classifications

• H02J13/12 Primary

  Monitoring network conditions, e.g. electrical magnitudes or operational status · CPC title

• H02J13/34 Primary

  the equipment being switches, relays or circuit breakers · CPC title

• H02H1/0061

  concerning transmission of signals (transmission of measured quantities or switching orders; sectionalised protection involving signal transmission between at least two stations H02H7/261; comparison of the voltage or current values at two spaced portions of a single system H02H3/28; transferring the output of a sensing member to another variable G01D5/00; electrical measuring arrangements using modulation of electromagnetic waves, e.g. light beams G01R15/24, G01R15/26) · CPC title

• H02H7/26

  Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured (locating faults in cables G01R31/08) · CPC title

• H02H3/021

  concerning the disconnection itself, e.g. at a particular instant, particularly at zero value of current, disconnection in a predetermined order (disconnection at zero value in general H03K17/18) · CPC title