Distributed protection system for power distribution systems

• US 20050273207A1
• Filed: 08/15/2005
• Published: 12/08/2005
• Est. Priority Date: 02/25/2002
• Status: Active Grant

• Current Assignee: ABB Schweiz AG (ABB Limited)
• Original Assignee: General Electric Company
• Inventors: Dougherty, John J.
• Granted Patent: US 7,532,955 B2
• Time in Patent Office: Days
• US Class Current: 700/292
• CPC Class Codes: G06F 1/12 Synchronisation of different clock signals provided by a plurality of clock generators
• CPC Class Codes: H01H 2300/03 Application domotique, e.g. for house automation, bus connected switches, sensors, loads or intelligent wiring
• 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: H02H 7/263 involving transmissions of measured values comparison of currents or voltages using pilot wires H02H3/30
• CPC Class Codes: H02J 13/00001 characterised by the display of information or by user interaction, e.g. supervisory control and data acquisition systems [SCADA] or graphical user interfaces [GUI]
• CPC Class Codes: H02J 13/00004 characterised by the power network being locally controlled
• CPC Class Codes: H02J 13/00007 using the power network as support for the transmission
• CPC Class Codes: H02J 13/00009 using pulsed signals
• 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 13/00028 involving the use of Internet protocols
• CPC Class Codes: H02J 13/00036 the elements or equipment being or involving switches, relays or circuit breakers circuits for indication of single switches H01H9/167
• CPC Class Codes: H02J 13/0004 involved in a protection system
• CPC Class Codes: H02J 2203/20 Simulating, e g planning, reliability check, modelling or computer assisted design [CAD]
• CPC Class Codes: H02J 2310/12 The local stationary network supplying a household or a building
• 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 3/007 : 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: Y02B 90/20 : Smart grids as enabling technology in buildings sector smart grids supporting the management or operation of end-user stationary applications in general, or like technologies with no associated climate change mitigation effect Y04S20/00
• CPC Class Codes: Y04S 20/14 : Protecting elements, switches, relays or circuit breakers
• CPC Class Codes: Y04S 20/20 : End-user application control systems
• 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 40/121 : using the power network as support for the transmission
• CPC Class Codes: Y04S 40/124 : using wired telecommunication networks or data transmission busses
• CPC Class Codes: Y04S 50/10 : Energy trading, including energy flowing from end-user application to grid

Abstract

There is disclosed a protection system for a power distribution system having a plurality of breakers arranged in a hierarchy. The protection system has a network and a breaker coupled to the power distribution system. A module is coupled to the network and the breaker is at a first level in the hierarchy. The module samples an electrical condition of the power distribution system at the breaker and monitors the electrical condition for a predetermined trip condition. The module, upon detection of the predetermined trip condition, trips said breaker if the first level is a lowest level of the hierarchy, but monitors the network for a notification message if the first level is not the lowest level of the hierarchy.

Claims

1. A protection system for a power distribution system having a plurality of breakers arranged in a hierarchy, the protection system comprising:

a network;

a first breaker of said plurality of breakers coupled to the power distribution system; and

a first module coupled to said network and said first breaker at a first level in the hierarchy, said first module sampling an electrical condition of the power distribution system at said breaker and monitoring said electrical condition for a predetermined trip condition,

wherein said first module, upon detection of said predetermined trip condition, trips said first breaker if said first level is a lowest level of the hierarchy, but monitors said network for a first notification message if said first level is not said lowest level of the hierarchy.

2. The protection system of claim 1, wherein said first notification message is generated by a second module.

3. The protection system of claim 2, wherein if a second breaker coupled to said second module is at higher level of the hierarchy than said first breaker coupled to said first module and if said first module detects said first notification message, said first module trips said first breaker.

4. The protection system of claim 3, wherein said first module generates a trip message after said first module trips said first breaker.

5. The protection system of claim 1, wherein said first module, upon detecting said predetermined trip condition, generates a second notification of trip condition message for said network.

6. The protection system of claim 2, wherein if said second breaker is at a lower level of the hierarchy than said first breaker, said first module monitors for a third notification of trip condition message from said network.

7. The protection system of claim 6, wherein said first module monitors for said third notification of trip condition during a first time interval.

8. The protection system of claim 7, wherein said first module places a trip message on said network and trips said breaker if a trip condition is detected at an expiration of said first time interval.

9. The protection system of claim 7, wherein said first module extends said first time interval to a second time interval if said third notification of trip condition message is received during said first time interval.

10. The protection system of claim 9, wherein said first module places a trip message on said network and trips said breaker if a trip condition is detected at an expiration of said second time interval.

11. A method for protecting a power distribution system having a plurality of breakers arranged in a hierarchy, comprising:

sampling an electrical condition of the power distribution system at a first breaker of the plurality of breakers by a first module;

detecting a trip condition by said first module based on said electrical condition;

determining whether a level of said first breaker is a lowest level in the hierarchy;

tripping said first breaker by said first breaker if said level is the lowest level; and

monitoring for a notification message if said level is not the lowest level.

12. The method of claim 11, further comprising generating said notification of trip condition message by a second module.

13. The method of claim 11, further comprising transmitting a second notification message on a network by said first module if a trip condition is detected.

14. The method of claim 11, further comprising:

employing a current differentiator to compare a plurality of breaker currents which source or feed current to a common power bus or device in the power distribution hierarchy; and

determining when a vector summation of said currents of said plurality of breakers do not match.

15. The method of claim 14, further comprising generating a phaselet as a function of said sampling of said electrical condition.

16. The method of claim 15, further comprising tripping at a main breaker in the hierarchy of breakers.

17. The method of claim 15, further comprising employing phaselet information for a communication of a breaker current from a first breaker to a second breaker over a network.

18. The method of claim 17, wherein said communication is a sub-cycle communication.

19. The method of claim 14, further comprising operating a designated source breaker when currents of said plurality of breakers do not match.

20. A storage medium for use with a power distribution system having a plurality of breakers arranged in a hierarchy, comprising:

instructions for sampling an electrical condition of the power distribution system at a breaker by a first module;

instructions for detecting a trip condition by said first module based on said electrical condition;

instructions for determining whether a level of a first breakers of the hierarchy of breakers is a lowest level in the hierarchy;

instructions for tripping said first breaker by said first module if said level is the lowest level; and

instructions for monitoring for a notification message if said level is not the lowest level.

21. The storage medium of claim 20, further comprising instructions for generating a phaselet as a function of said sampling of said electrical condition.

22. The storage medium of claim 20, further comprising instructions for conveying said phaselet to a network for high level functions.

23. The storage medium of claim 20, further comprising instructions for generating said notification message by a second module.

24. A protection system for a power distribution system having a plurality of breakers arranged in a hierarchy, the protection system comprising:

a network;

a first breaker of said plurality of breakers coupled to the power distribution system; and

a first module coupled to said network and said first breaker at a first level in the hierarchy, said first module sampling an electrical condition of the power distribution system at said breaker and monitoring said electrical condition and said network for a control condition, said first module further broadcasting said electrical condition on said network to a second module;

wherein said first module, upon detection of said control condition, performs an action selected from the group consisting of an opening or a closing of said first breaker.

25. The system of claim 24, wherein said control condition is a demand request.

26. The system of claim 24, wherein said control condition employs a boolean combination of breaker electrical condition and other breaker electrical conditions broadcast on the network.

27. The system of claim 26, wherein said control condition is programmed by selected from the group consisting of programmed locally or programmed over said network.

28. The system of claim 24, wherein said control condition employs a boolean combination of system electrical conditions and discrete and analog user inputs, said boolean combination broadcast on the network from a plurality of network-connected modules.

29. A protection system for a power distribution system having a plurality of breakers arranged in a hierarchy, the protection system comprising:

a network;

a plurality of modules coupled to said network and said plurality of breakers, wherein said plurality of modules sample and store a plurality of raw samples indicative of a power distribution system status;

wherein said raw samples are time-tagged via a synchronization message received over said network; and

a circular buffer module memory that stores said plurality of time-tagged raw samples, wherein said circular buffer module memory stops storing said plurality of raw samples after a local or system event, said local or system event having an associated event time,

wherein said circular buffer module memory stores said event time and a corresponding event description in said circular buffer module memory, and wherein said circular buffer circular buffer module memory maintains said time-tagged raw samples, said event description, and said event time.

30. The system of claim 30, wherein said raw samples are converted to a plurality of metering values, said metering values are time tagged, and said time tagged metering values are stored for future access in said circular buffer module memory.

31. The system of claim 31, wherein said plurality of modules communicate over said network to a Human Machine Interface by transferring information in said time tagged circular buffers and said metering information in said circular buffer module memory.