Energy calculation methods in power distribution systems

• US 20040133370A1
• Filed: 09/15/2003
• Published: 07/08/2004
• Est. Priority Date: 01/06/2003
• Status: Active Grant

• Current Assignee: ABB Schweiz AG (ABB Limited)
• Original Assignee: General Electric Company
• Inventors: Premerlani, William James, Berkcan, Ertugrul, Papallo, Thomas F., Lavoie, Gregory P.
• Granted Patent: US 7,012,421 B2
• Time in Patent Office: Days
• US Class Current: 702/60
• CPC Class Codes: G06F 1/12 Synchronisation of different clock signals provided by a plurality of clock generators
• CPC Class Codes: H02H 1/0061 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 Class Codes: H02H 3/006 Calibration or setting of parameters
• CPC Class Codes: H02H 3/05 with means for increasing reliability, e.g. redundancy arrangements for logic circuits H03K19/003
• CPC Class Codes: H02J 13/00012 using an auxiliary transmission line
• CPC Class Codes: H02J 13/00016 using a wired telecommunication network or a data transmission bus
• CPC Class Codes: H02J 13/00018 using phone lines
• CPC Class Codes: H02J 13/0004 involved in a protection system
• CPC Class Codes: H02J 2310/64 The condition being economic, e.g. tariff based load management
• CPC Class Codes: H02J 3/0012 Contingency detection
• CPC Class Codes: H02J 3/00125 Transmission line or load transient problems, e.g. overvoltage, resonance or self-excitation of inductive loads H02J3/01 takes precedence
• CPC Class Codes: H02J 3/007 Arrangements for selectively connecting the load or loads to one or several among a plurality of power lines or power sources for providing uninterruptable power supply H02J9/00
• CPC Class Codes: Y02B 70/30 Systems integrating technologies related to power network operation and communication or information technologies for improving the carbon footprint of the management of residential or tertiary loads, i.e. smart grids as climate change mitigation technology in the buildings sector, including also the last stages of power distribution and the control, monitoring or operating management systems at local level
• CPC Class Codes: Y02B 70/3225 Demand response systems, e.g. load shedding, peak shaving
• CPC Class Codes: Y04S 20/221 General power management systems
• CPC Class Codes: Y04S 20/222 Demand response systems, e.g. load shedding, peak shaving
• CPC Class Codes: Y04S 50/10 Energy trading, including energy flowing from end-user application to grid

Abstract

A method of performing energy calculations in a power distribution system is provided. The method includes sampling a first voltage at a first module in the power distribution system; communicating the first voltage from the first module to a central controller; performing an energy calculation in the central controller based at least in part on the first voltage; and applying the energy calculation to a second module in the power distribution system. In some embodiments, the energy calculation is also based upon a second current from the second module.

Claims

1. A method of performing energy calculations in a power distribution system, said method comprising:

sampling a first voltage at a first module in the power distribution system;

communicating said first voltage from said first module to a central controller;

performing an energy calculation in said central controller based at least in part on said first voltage; and

applying said energy calculation to a second module in the power distribution system.

2. The method as in claim 1, further comprising:

sampling a second current at said second module;

communicating said second current from said second module to said central controller; and

performing said energy calculation in said central controller using said first voltage and said second current, said second current and said first voltage are for a predetermined time window.

3. The method as in claim 2, wherein said energy calculation is one selected from the group consisting of watts, watt-hours, varhours, vars, VA hours, VA, and power factor.

4. The method as in claim 1, further comprising determining a function of the power distribution system based at least in part on said energy calculation.

5. The method as in claim 4, wherein said function is selected from the group consisting of undervoltage detection, reverse power flow, low power factor, overvoltage, voltage imbalance, voltage relays, and power relays.

6. The method as in claim 1, further comprising sampling a third voltage at a third module in the power distribution system;

communicating said third voltage from said third module to said central controller;

controlling said central controller to perform said energy calculation based at least in part on said third voltage instead of said first voltage; and

applying said energy calculation to said second module.

7. The method as in claim 6, wherein said central controller is controlled to perform said energy calculation based at least in part on said third voltage instead of said first voltage in response to a condition of said power distribution system.

8. The method as in claim 7, wherein said condition is a switchover from said first module to said third module.

9. The method as in claim 1, further comprising accessing a sensor identifier resident on said central computer, said sensor identifier identifying a location of said first module.

10. A power distribution system comprising:

a main breaker for distributing power from a first power source to a power bus;

a first module in communication with said main breaker, said first module sampling a first voltage of said power at said main breaker;

a feeder-breaker for receiving said power from said power bus;

a second module in communication with said feeder-breaker; and

a central computer in communication with said first and second modules over a data network so that said central computer can determine an energy calculation of said second module based at least in part on said first voltage.

11. The system as in claim 10, wherein said second module comprises only a current sensor.

12. The system as in claim 10, wherein said second module samples a second current of said power at said feeder-breaker.

13. The system as in claim 12, wherein said first voltage and said second current are sampled at substantially the same time.

14. The system as in claim 12, wherein said central computer determine said energy calculation of said second module based at least in part on said first voltage and said second voltage.

15. The system as in claim 10, further comprising a voltage sensor source identifier resident on said central computer, said central computer determining a source of voltage for said energy calculation based on said voltage sensor source identifier.

16. A method of performing energy calculations in a power distribution system, said method comprising:

sending a first voltage indicative of a voltage at a first module in the power distribution system to a central computer;

performing an energy calculation in said central controller based at least in part on said first voltage; and

applying said energy calculation to a second module in the power distribution system.

17. The method as in claim 16, further comprising accessing a sensor identifier resident on said central computer, said sensor identifier identifying a location of said first module.

18. The method as in claim 17, further comprising sending a second current indicative of a current at said second module to said central computer and performing said energy calculation based at least in part on said first voltage and said second current.

19. The method as in claim 18, wherein said first voltage and said second current are sampled at substantially the same time.

20. The method as in claim 16, further comprising:

sending a third voltage indicative of a voltage at a third module in the power distribution system to a central computer;

performing said energy calculation in said central controller based at least in part on said third voltage instead of said first voltage; and

applying said energy calculation to said second module.

21. The method as in claim 20, wherein said central controller is controlled to perform said energy calculation based at least in part on said third voltage instead of said first voltage in response to a condition of said power distribution system.

22. The method as in claim 21, wherein said condition is a switchover from said first module to said third module.

23. A power distribution system comprising:

a first breaker for distributing power from a first power source to a power bus;

a first module in communication with said first breaker, said first module having a first current sensor for generating a first current signal of said power at said first breaker;

a second breaker for receiving said power from said power bus and distributing said power to a load;

a second module in communication with said second breaker, said second module having a second current sensor for generating a second current signal of said power at said second breaker; and

a central computer in communication with said first and second modules over a data network, said central computer having a first polarity parameter so that said central computer can compensate for a polarity of said power flowing through said first breaker to a first selected polarity, and said central computer having a second polarity parameter so that said central computer can compensate for a polarity of said power flowing through said second breaker to a second selected polarity.