System for monitoring and assessing electrical circuits and method of operation

• US 8,135,550 B2
• Filed: 12/09/2008
• Issued: 03/13/2012
• Est. Priority Date: 12/09/2008
• Status: Active Grant

• Current Assignee: Consolidated Edison Company of New York Incorporated (Consolidated Edison Incorporated), Softstuf, Inc.
• Original Assignee: Consolidated Edison Company of New York Incorporated (Consolidated Edison Incorporated), Softstuf, Inc.
• Inventors: Bose, Sanjay, Giuliante, Anthony T., Makki, Amir, Makki, Maria Rothweiler
• Primary Examiner(s): Raymond, Edward
• Assistant Examiner(s): SUAREZ, FELIX E
• Application Number:
  US12/331,043
• Publication Number:
  US 20100145641A1
• Time in Patent Office: 1,190 Days
• Field of Search: 702/58, 702/60, 702/62, 702/85, 702/117, 702/181, 702/182, 702/188, 702/57, 702/69, 376/259, 700/17
• US Class Current: 702/58
• CPC Class Codes: G01R 31/327 Testing of circuit interrupters, switches or circuit-breakers

Abstract

A system for collecting data and monitoring the operation of electrical circuits, such as branch circuits at a substation is provided. The system collects data from a plurality of sensors coupled to a plurality of electrical equipment associated with a circuit. The data from the sensors is collected and used to determine the activation of the electrical equipment, such as a protective relay for example. The data is further transformed to allow assessment of the circuit'"'"'s performance against desired parameters.

Claims

1. A method of identifying a relay, said method operable via a processor, said method comprising:

coupling a first plurality of sensors to a relay trip ladder, wherein each of said first plurality of sensors is associated with one of a plurality of relays;

collecting a first electrical data from said first plurality of sensors;

identifying a trip signal on said trip ladder;

determining a first relay of said plurality of relays from said first electrical data, wherein said first relay generated said trip signal;

coupling a second plurality of sensors to a secondary side of a current transformer, wherein each of said second plurality of sensors is associated with one of said plurality of relays;

collecting a second electrical data from said second plurality of sensors;

determining a second relay from said second electrical data, wherein said second relay detected an electrical anomaly; and

,

generating an exception report indicating said trip signal and said identified relay, said exception report including a time, duration and description of the exception.

2. The method of claim 1, further comprising the step of determining said second relay identified as generating said trip signal also detected an electrical anomaly.

3. The method of claim 2, further comprising the step of generating an exception report when said first relay did not detect an electrical anomaly.

4. The method of claim 2, further comprising the step of generating an exception report when said first relay identified as detecting an electrical anomaly did not generate a trip signal.

5. The method of claim 2 further comprising:

coupling a current sensor to a circuit breaker;

collecting a third electrical data from said current sensor; and

,

measuring the length of time from the initiation of said trip signal to the opening of a circuit breaker electrically coupled to said trip ladder.

6. The method of claim 1, further comprising:

determining if said trip signal is detected at different current levels by said first plurality of sensors; and

,

determining a third relay from said first electrical data, wherein said sensor from said first plurality of sensors associated with said third relay measured said trip signal at a different current level from said sensor of said first plurality of sensors that is associated with said first relay.

7. A method of identifying an activated relay in a protective relay cabinet, where said protective relay cabinet includes a first relay, a second relay and a third relay, each of said first relay, said second relay and said third relay being operably coupled to a circuit breaker by a trip ladder, said method operable via a processor, said method comprising:

coupling a first sensor to said trip ladder adjacent said first relay;

coupling a second sensor to said trip ladder adjacent said second relay;

coupling a third sensor to said trip ladder adjacent said third relay;

detecting a trip signal on said trip ladder;

determining which of said first sensor, said second sensor and said third sensor measured said trip signal;

determining said second relay generated said trip signal;

coupling a fourth sensor to a secondary connection of a first current transformer associated with said first relay;

coupling a fifth sensor to a secondary connection of a second current transformer associated with said second relay;

coupling a sixth sensor to a secondary connection of a third current transformer associated with said third relay;

detecting an electrical anomaly on said fourth sensor; and

,

determining if said second relay generated said trip signal;

generating an exception report if said fifth sensor measured an electrical anomaly and said second relay did not generate said trip signal said exception report including a time, duration and description of the exception.

8. The method of claim 7 further comprising determining if said first sensor detected said trip signal at a current level that was larger than said second sensor.

9. A system of assessing an electrical circuit on an electrical utility network, said system comprising a processor configured to perform a method, said method comprising:

collecting a first data set of a first electrical parameter current during a first time period representing a first electrical parameter on a portion of said electrical utility network;

collecting a second data set of said first electrical parameter during a second first time period representing a second electrical parameter on a portion of said electrical utility network;

creating with said processor a graphical plot of said first data set and said second data set;

comparing with said processor a characteristic of said graphical plot to a threshold parameter;

determining that said threshold parameter has been violated by said characteristic.

10. The system of claim 9 further comprising the step of initiating an action when said threshold parameter has been violated.

11. The system of claim 10 further comprising the step of overlaying said second data set on said first data set.

12. The system of claim 11 wherein said characteristic is a percentage of the area of the first data set that is visible.

13. The system of claim 11 wherein said threshold is a rating parameter for the circuit.

14. The system of claim 13 wherein said characteristic is a percentage of a peak current to said rating parameter.

15. The system of claim 11 wherein said threshold parameter is violated if said second data set is positioned radially outward of said first data set.

16. The system of claim 15 wherein said first data set is real power data and said second data set is reactive power data.

17. The system of claim 12 further comprising:

collecting a third data set representing a third electrical parameter;

collecting a fourth data set representing a fourth electrical parameter;

creating a polar plot of said first data set, said second data set, said third data set and said fourth data set, wherein said second data set overlays said first data set, said third data set and said fourth data set; and

,

wherein said second data set is an average of said first data set, said third data set and said fourth data set.

18. The system of claim 17 wherein said first data set is a first electrical phase current, said third data set is a second electrical phase current, and said fourth data set is a third electrical phase current.

19. A system of assessing an electrical circuit on an electrical utility network, said system having a processor configured to perform a method, said method comprising:

collecting a first data set representing a first electrical parameter on a portion of said electrical utility network;

collecting a second data set representing a second electrical parameter on said portion of said electrical utility network;

collecting a third data set representing a third electrical parameter on said portion of said electrical utility network;

storing on a tangible storage medium said first data set, said second data set and said third data set;

generating with said processor a polar plot of said stored first data set, said stored second data set, and said stored third data set;

comparing with said processor a characteristic of said polar plot to a threshold parameter;

transmitting an alarm signal with said processor if said threshold parameter has been violated by said characteristic.

20. The system of claim 19 further comprising:

calculating a fourth data set by averaging said stored first data set, said stored second data set and said stored third data set; and

,

overlaying said fourth data set on said polar plot.

21. The system of claim 20 wherein said threshold parameter is a percentage of an area of said fourth data set that covers said stored first data set, said stored second data set and said stored third data set on said polar plot.

22. The system of claim 20 further comprising the step of generating a rating line on said polar plot.

23. The system of claim 22 wherein said threshold parameter is a percentage of a peak current from said fourth data set to said rating line.

24. The system of claim 23 wherein said first electrical parameter represents electrical current from a first electrical phase, said second electrical parameter represents electrical current from a second electrical phase, and said third electrical parameter represents electrical current from a third phase.

25. A system for assessing an electrical circuit on an electrical utility network, said system comprising:

a first sensor measuring a first electrical parameter of said electrical circuit on a portion of said electrical utility network;

a second sensor measuring a second electrical parameter of said electrical circuit on a portion of said electrical utility network;

a data storage device operably coupled to store data received from said first sensor and said second sensor; and

,

a controller responsive to executable computer instructions when executed on the controller for generating a polar plot of said stored data, said controller further responsive to executable instructions to compare a characteristic of said polar plot to a threshold parameter, determining if said threshold parameter has been exceeded and transmitting an alarm signal in response to said threshold parameter.

26. The system of claim 25 wherein:

said controller is further responsive to calculate an average of said stored data and said characteristic is determined from said calculated average; and

,

said first electrical parameter is an electrical current for a first phase of said electrical circuit and said second electrical parameter is an electrical current for a second phase of said electrical circuit.

27. The system of claim 25 wherein:

said characteristic is a relative position of said stored data from said first sensor to a position of said stored data from said second sensor;

said first electrical parameter is real power flowing through said electrical circuit; and

,

said second electrical parameter is reactive power flowing through said electrical circuit.