Energy monitoring system for a plurality of local stations with snapshot polling from a central station

• US 5,315,531 A
• Filed: 07/15/1992
• Issued: 05/24/1994
• Est. Priority Date: 08/15/1991
• Status: Expired due to Term

• Current Assignee: Eaton Corp. (Wisconsin) (Eaton Corporation PLC.)
• Original Assignee: Westinghouse Electric Corporation (Paramount Global (f/k/a ViacomCBS Inc.))
• Inventors: Elms, Robert T., Engel, Joseph C., Kenny, Thomas J., Oravetz, David M., Klancher, Frank
• Primary Examiner(s): Harvey, Jack B.
• Assistant Examiner(s): Buroker, Brian M.
• Application Number:
  US07/915,171
• Time in Patent Office: 678 Days
• Field of Search: 364/483, 364/492, 364/550, 364/464.04, 324/114, 324/115, 324/116, 324/103 R, 324/142, 340/310 R, 340/310 A, 340/870.02, 340/870.03, 361/412, 361/413, 361/364, 361/331
• US Class Current: 702/62
• CPC Class Codes: G01R 21/133 by using digital technique

Abstract

A PC computer monitors the energy, power, voltage, and current consumed at a plurality of local stations placed behind the electrical meter of the utility company for individual billing of the local users, a bidirectional communication line being used therebetween. A command from the PC computer causes at each station the power, voltage, current and totalized energy to be stored, and thereafter the PC computer derives individually the results for separate estimations and central billing.

Claims

1. An electrical monitoring system for use on an AC line, comprising:

a circuit breaker installed on said AC line;

a backpack unit mounted on said circuit breaker and having an opening through which said AC line is passed and wherein said backpack unit further has mounted therein transducer means cooperating with said AC line for deriving analog signals representative of AC line current and voltage, analog to digital means for converting said analog signals to digital signals, and processing means for computing electrical measurements from said digital signals;

a remote monitoring device for retrieving said computed electrical measurements; and

bi-directional digital communication means linking said backpack unit and said remote monitoring device for establishing a data highway therebetween.

2. The monitoring system of claim 1, wherein said transducer means comprises a current transducer inductively coupled with said AC line and a voltage metering device connected to said AC line.

3. The monitoring system of claim 2, further comprising a PC board mounted in said backpack unit having an opening around which is mounted said current transducer and wherein said AC line is passed through said opening and through said current transducer.

4. The monitoring system of claim 3, wherein said analog to digital means and said processing means are integrated in a CMOS monolithic circuit.

5. The monitoring system of claim 4, further comprising a second PC board mounted in said backpack unit on which said CMOS monolithic circuit is mounted.

6. The monitoring system of claim 3, wherein said circuit breaker has a female terminal into which said AC line is inserted and wherein said backpack unit has a stab cooperating with said female terminal for mounting said backpack unit on said circuit breaker, said stab providing the connection between said AC line and said voltage metering device.

7. The monitoring system of claim 6, wherein at least one of said computed electrical measurements is a value representative of an RMS current value associated with said AC line.

8. The monitoring system of claim 6, wherein at least one of said computed electrical measurements is a value representative of an RMS voltage value associated with said AC line.

9. The monitoring system of claim 6, wherein at least one of said computed electrical measurements is a set of values representative of power values associated with said AC line.

10. The monitoring system of claim 6, wherein at least one of said computed electrical measurements is a value representative of an energy value associated with said AC line.

11. An electrical monitoring system for use behind a collective electrical meter having a plurality of AC lines associated therewith, said electrical monitoring system comprising:

a plurality of circuit breakers wherein each of said AC lines has installed thereon one of said plurality of circuit breakers;

a plurality of backpack units individually mounted on each of said circuit breakers, each of said backpack units having an opening through which said AC line passes, so that a backpack unit mounts to a circuit breaker and an AC line passes through the backpack unit and connects to the circuit breaker, and wherein each of said backpack units further has transducer means cooperating with said AC line for deriving analog signals representative of AC line current and voltage, analog to digital means for converting said analog signals to digital signals, processing means for computing electrical measurements from said digital signals, and storage means for saving said electrical measurements;

a remote monitoring device for retrieving said electrical measurements from each of said plurality of backpack units; and

bi-directional digital communication means linking said remote monitoring device to each of said plurality of backpack units for establishing a data highway therebetween.

12. The monitoring system of claim 11, wherein said bi-directional communication means is used at regular successive intervals by said remote monitoring device to initially and simultaneously address and command each of said plurality of backpack units to store said electrical measurements whereby said remote monitoring device may address and poll each of said plurality of backpack units individually to retrieve said stored electrical measurements.

13. The monitoring system of claim 12, wherein said transducer means comprises a current transducer inductively coupled with said AC line and a voltage metering device connected to said AC line.

14. The monitoring system of claim 13, wherein each of said plurality of backpack units further has a PC board mounted therein having an opening around which is mounted said current transducer and wherein said AC line passes through said opening and through said current transducer.

15. The monitoring system of claim 14, wherein said analog to digital means and said processing means are integrated in a CMOS monolithic circuit.

16. The monitoring system of claim 15, wherein each of said plurality of backpack units further has a second PC board on which said CMOS monolithic circuit is mounted.

17. The monitoring system of claim 14, wherein each of said plurality of circuit breakers has a female terminal into which said AC line is connected and wherein each of said backpack units has a stab cooperating with said female terminal for mounting said backpack unit on said circuit breaker and wherein said stab provides the connection between said AC line and said voltage metering device.

18. The monitoring system of claim 17, wherein at least one of said electrical measurements is a value representative of an RMS current value associated with the individual AC line to which said backpack unit is connected.

19. The monitoring system of claim 17, wherein at least one of said electrical measurements is a value representative of an RMS voltage value associated with the individual AC line to which said backpack unit is connected.

20. The monitoring system of claim 17, wherein at least one of said electrical measurements is a set of values representative of power values associated with the individual AC line to which said backpack unit is connected.

21. The monitoring system of claim 17, wherein at least one of said electrical measurements is a value representative of an energy consumption associated with the individual AC line to which said backpack unit is connected.