Electrical transmission or interconnection systems – Conductor arrangements or structure
Reexamination Certificate
1998-06-23
2001-07-10
Fleming, Fritz (Department: 2836)
Electrical transmission or interconnection systems
Conductor arrangements or structure
C361S731000
Reexamination Certificate
active
06259173
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to protective relays. More particularly, the present invention relates to protective relays which include interchangeable parts.
BACKGROUND OF THE INVENTION
Protective relay devices are necessary elements of an electrical power distribution system, as they provide a variety of protection and control functions. Protective relays monitor conditions in the power distribution system and operate circuit breakers in response to the detection of adverse conditions, thereby protecting various segments and components of the power distribution system from damage.
Older protective relays were analog devices, which have been largely replaced by digital protective relays. Digital protective relays include digital processing circuitry which can be programmed to provide a wider variety of protection and control functions than were available with analog relay devices.
Typically, digital protective relays include relay processing circuitry to perform various protective control functions. The relay processing circuitry can be implemented by various configurations of input/output (I/O) circuits, current transformers, voltage transformers, etc. These configurations are generally fixed within the protective relay unit, making it relatively difficult and time-consuming to repair or replace the relay processing circuitry or portions thereof.
U.S. Pat. No. 4,742,428 to Conrad discloses a protective relay which includes an operating unit that can be withdrawn from an insulating housing through an opening in the front of the housing. The withdrawability of the protective relay circuitry allows for routine testing, maintenance, and replacement of the internal relay circuitry with minimal disruption of the power distribution system. However, the Conrad protective relay includes otherwise conventional relay circuitry which is fixed in location within the withdrawable operating unit.
It would be desirable for a protective relay device to allow relatively easy replacement or repair of relay processing circuitry.
SUMMARY OF THE INVENTION
The present invention overcomes the above-described problems, and achieves additional advantages, by providing for a protective relay in which the relay processing circuitry is implemented in the form of removable and replaceable modules, each of which performs a specified function. Each module includes a main control board having basic circuitry required for all intended module functions, and also includes removable and replaceable submodules which include specialized circuitry for performing specific functions. The modules can include a power supply module, a CPU module, and at least one digital signal processing module. The submodules can include I/O cards and voltage or current transformer cards. According to the exemplary embodiments disclosed below, the present invention allows the functions of a protective relay to be changed by replacement of one or more modules or one or more submodules.
REFERENCES:
patent: Re. 34064 (1992-09-01), Tury et al.
patent: 5021764 (1991-06-01), Mabee
patent: 5042133 (1991-08-01), Peterson et al.
patent: 5065135 (1991-11-01), Leigh-Monstevens et al.
patent: 5207613 (1993-05-01), Ferchau et al.
patent: 5237484 (1993-08-01), Ferchau et al.
patent: 5243522 (1993-09-01), Salzmann
patent: 5289363 (1994-02-01), Ferchau et al.
patent: 5751536 (1998-05-01), Haddad et al.
patent: 5752047 (1998-05-01), Darty et al.
patent: 5811878 (1998-09-01), Harmoinen et al.
patent: 5841634 (1998-11-01), Visser
patent: 5978220 (1999-11-01), Frey et al.
patent: 6014705 (2000-01-01), Koenck et al.
Dias Clive
Pozzuoli Marzio
Duncan Kevin T.
Fleming Fritz
General Electric Company
Horton Carl B.
Hunton & Williams
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