WO2008067299A2

WO2008067299A2 - Method and system for isolating disturbances to the power distribution system

Info

Publication number: WO2008067299A2
Application number: PCT/US2007/085622
Authority: WO
Inventors: John Arthur Teselle; Douglas Martin Johns
Original assignee: Firstenergy Corp.
Priority date: 2006-11-27
Filing date: 2007-11-27
Publication date: 2008-06-05
Also published as: WO2008067299A3

Abstract

A method and system for isolating disturbances to an electric energy or power distribution system upon the occurrence of an initiating trigger. The electric energy or power distribution system is monitored for a fault condition and a loss of voltage. The initiating trigger is responding to and isolated to minimize the number of end users affected while further providing information t indicative of the location of the disturbance.

Description

METHOD AND SYSTEM FOR ISOLATING DISTURBANCES TO THE POWER

DISTRIBUTION SYSTEM

This invention claims priority to U.S. Serial No. 60/861,343 titled Method and

System for Isolating Disturbances to the Power Distribution System, filed November 27, 2006, which is hereby incorporated by reference.

I. Background of the Invention

A. Field of Invention

The present invention is directed generally to a method and system for protecting an electric-energy distribution system, and more specifically, to a method and system for monitoring the electric-energy distribution system for a fault condition and a loss of voltage, responding to isolate such a disturbance to minimize a number of customers affected by such a disturbance, and provided information indicative of a location of the disturbance.

B. Description of the Related Art

Traditionally, fault-isolation methods and systems have relied on circuit interrupters for disconnecting a problematic portion of an electric-energy distribution system from the remainder of the distribution system. Such systems include a tiered structure of protective measures to provide the distribution system with several layers of protection. An example of such a system includes a recloser upstream of a plurality of local switches to control the delivery of electric energy to those local switches. Thus, when the recloser is opened the transmission of electric energy to the local switches downstream of the open recloser is discontinued. Likewise, when one of the local switches is opened, the transmission of electric energy to local structures such as residential homes is discontinued. The further upstream a protective measure is in the distribution system, the more end users are affected when that protective measure is triggered.

Disturbances to the distribution system include a loss of voltage and a fault, which is considered to be an over-current condition where the current flowing through the distribution system exceeds a threshold level. One technique for isolating such disturbances requires each switching station along a branch of the distribution system to communicate when a disturbance anywhere in that branch is detected. The communication between the local switching stations causes each switching station along the affected branch to open, thereby disconnecting the consumers of the electric energy downstream from each such switching station to experience a loss of electric-energy service. The communication between the local switching stations causes all the switching stations along the affected branch to remain open until the cause of the disturbance has been located and rectified. However, because the transmission of electric energy is discontinued uniformly along the entire affected branch, the entire affected branch must be manually inspected to locate the cause of the disturbance.

Another technique for protecting the distribution system focuses its attention on the recloser upstream of the local switching stations. When a fault condition is detected, the recloser temporarily opens to isolate the downstream portion of the distribution system in which the fault condition was detected from the rest of the distribution system that lacks the fault condition. Upon opening for a brief moment, the recloser automatically closes again without intervention by an operator to restore the transmission of electric energy to the downstream portion of the distribution system. If the fault condition was temporary and is no longer present when the recloser is returned to the closed state, then the recloser remains closed and the distribution system returned to normal operating conditions. If the fault condition persists, however, the recloser temporarily opens and then closes following a brief delay for a second time. Again, if the fault has been cleared, the recloser remains closed, but if the fault remains, a third

::ODMA\PCDOCS\BROUSE\698606\1 O opening and closing of the recloser is performed. If, at this point the fault remains, the recloser remains open, but if the fault is cleared, the recloser remains closed.

When the recloser is left in the open state following the third attempt to clear the fault condition, each local switching station downstream of the open recloser is then opened, and the recloser returned to its closed state and reset. Thus, the conducting pathway is reestablished downstream to the local switching stations. Each local switching station not affected by the fault condition must then be manually reset by an operator, thereby isolating the fault to the local switching station(s) affected by the fault condition. But again, the uniform loss of power experience by all switching stations downstream of the open recloser requires an operator to manually locate the fault condition and isolate it at the affected switching stations.

Accordingly, there is a need in the art for a method and system for protecting an electrical-energy distribution system that minimizes the number of electricity consumers who experience a disruption in electric energy service. The method and system can also provide information indicative of a location of a fault condition and a loss of voltage.

II. Summary of the Invention

According to one embodiment of the invention, a method for isolating disturbances to a power distribution system may comprise the steps of:

(a) providing a first electric energy distribution network for distributing electric energy to a plurality of end users comprising: a first device, wherein the first device supplies electric energy generated from a generation facility to the first electric energy distribution network so as to establish an electrical connection; a second device, wherein the second device comprises a circuit breaker device that is operable to establish and break the electrical connection between the first device and the first electric energy distribution network, wherein the second device is

::ODMA\PCDOCS\BROUSE\698606\1 downstream from the first device and upstream from a plurality of circuit interrupting devices; the plurality of circuit interrupting devices, wherein the plurality of circuit interrupting devices are upstream from the plurality of end users and a third device; and, the third device, wherein the third device is a normal open point that interconnects the first electric energy distribution network to a second electric energy distribution network;

(b) monitoring the first electric energy distribution network for the occurrence of an initiating trigger; (c) detecting the occurrence of the initiating trigger within the first electric energy distribution network;

(d) detecting a device operational state of the first device, the second device, the third device, and the plurality of circuit interrupting devices;

(e) detecting whether a fault condition occurred downstream from the first device, the second device, the third device, or the plurality of circuit interrupting devices beginning with a normal open point of the second electric energy distribution network and progressing to the third device in the upstream direction;

(f) detecting the presence of a voltage across the first device, the second device, the third device, and the plurality of circuit interrupting devices; (g) populating a decision table with data indicative of the operational state, whether a fault condition has occurred, and whether there is a voltage present across the first device, the second device, the third device, and each of the plurality of circuit interrupting devices;

(h) analyzing the decision table to determine if an abnormal device operational state exists with respect to the first device, the second device, the third device, or at least one of the plurality of circuit interrupting devices, wherein upon determining the presence of an abnormal device operational state a first protection scheme is initiated with respect to the first electric energy distribution network and steps (d) - (h) are repeated until an abnormal device operation state is determined not to exist with respect to the first device, the second device, the third device, and the plurality of circuit interrupting devices;

::ODMA\PCDOCS\BROUSE\698606\1 A (i) analyzing the decision table to determine the presence of a fault condition exists with respect to the first device, the second device, the third device, or at least one of the plurality of circuit interrupting devices; wherein upon determining the presence of a fault condition the device immediately upstream from the fault condition is determined to be a faulted device and the faulted device and the device immediately downstream from the faulted device are opened;

(j) analyzing the decision table to determine the presence of a voltage across the first device, wherein the method is terminated if a voltage is determined to not be present across the first device; (k) analyzing the decision table to determine the presence of a voltage across the normal open point of the second electric energy distribution network, wherein the method is terminated if a voltage is determined to not be present across the normal open point of the second electric energy distribution network;

(1) analyzing the decision table to determine the presence of a voltage across each of the plurality of circuit interrupting devices;

(m) opening one of the plurality of circuit interrupting devices upon detecting that a voltage is not present across the respective plurality of circuit interrupting devices.

According to another embodiment of the invention, a method for isolating disturbances to a power distribution system may comprise the steps of:

(a) providing a first electric energy distribution network for distributing electric energy to a plurality of end users comprising: a first device, wherein the first device supplies electric energy generated from a generation facility to the first electric energy distribution network so as to establish an electrical connection; a second device, wherein the second device comprises a circuit breaker device that is operable to establish and break the electrical connection between the first device and the first electric energy distribution network, wherein the second device is downstream from the first device and upstream from a plurality of circuit interrupting devices;

::ODMA\PCDOCS\BROUSE\698606\1 the plurality of circuit interrupting devices, wherein the plurality of circuit interrupting devices are upstream from the plurality of end users and a third device; and, the third device, wherein the third device is a normal open point that interconnects the first electric energy distribution network to a second electric energy distribution network; and, independently selecting the plurality of circuit interrupting devices from the group consisting of: a recloser, a sectionalizer, or a switch;

::ODMA\PCDOCS\BROUSE\698606\1 f. (i) analyzing the decision table to determine the presence of a fault condition exists with respect to the first device, the second device, the third device, or at least one of the plurality of circuit interrupting devices; wherein upon determining the presence of a fault condition the device immediately upstream from the fault condition is determined to be a faulted device and the faulted device and the device immediately downstream from the faulted device are opened;

::ODMA\PCDOCS\BROUSE\698606\1 the plurality of circuit interrupting devices, wherein the plurality of circuit interrupting devices are upstream from the plurality of end users and a third device; and, the third device, wherein the third device is a normal open point that interconnects the first electric energy distribution network to a second electric energy distribution network; and, operatively coupling the first device, the second device, the third device, and each of the plurality of circuit interrupting devices to communicate with a common control unit;

(b) monitoring the first electric energy distribution network for the occurrence of an initiating trigger;

(c) detecting the occurrence of the initiating trigger within the first electric energy distribution network;

(d) detecting a device operational state of the first device, the second device, the third device, and the plurality of circuit interrupting devices; (e) detecting whether a fault condition occurred downstream from the first device, the second device, the third device, or the plurality of circuit interrupting devices beginning with a normal open point of the second electric energy distribution network and progressing to the third device in the upstream direction;

(f) detecting the presence of a voltage across the first device, the second device, the third device, and the plurality of circuit interrupting devices;

(g) populating a decision table with data indicative of the operational state, whether a fault condition has occurred, and whether there is a voltage present across the first device, the second device, the third device, and each of the plurality of circuit interrupting devices; (h) analyzing the decision table to determine if an abnormal device operational state exists with respect to the first device, the second device, the third device, or at least one of the plurality of circuit interrupting devices, wherein upon determining the presence of an abnormal device operational state a first protection scheme is initiated with respect to the first electric energy distribution network and steps (d) - (h) are repeated until an abnormal device operation state is determined not to exist with respect

::ODMA\PCDOCS\BROUSE\698606\1 to the first device, the second device, the third device, and the plurality of circuit interrupting devices;

(i) analyzing the decision table to determine the presence of a fault condition exists with respect to the first device, the second device, the third device, or at least one of the plurality of circuit interrupting devices; wherein upon determining the presence of a fault condition the device immediately upstream from the fault condition is determined to be a faulted device and the faulted device and the device immediately downstream from the faulted device are opened;

(j) analyzing the decision table to determine the presence of a voltage across the first device, wherein the method is terminated if a voltage is determined to not be present across the first device;

(k) analyzing the decision table to determine the presence of a voltage across the normal open point of the second electric energy distribution network, wherein the method is terminated if a voltage is determined to not be present across the normal open point of the second electric energy distribution network;

::ODMA\PCDOCS\BROUSE\698606\1 downstream from the first device and upstream from a plurality of circuit interrupting devices; the plurality of circuit interrupting devices, wherein the plurality of circuit interrupting devices are upstream from the plurality of end users and a third device; and, the third device, wherein the third device is a normal open point that interconnects the first electric energy distribution network to a second electric energy distribution network; operatively coupling the first device, the second device, the third device, and each of the plurality of circuit interrupting devices to communicate with a common control unit; and, displaying the decision table on a display device, wherein the display device is operatively coupled to the control unit;

(h) analyzing the decision table to determine if an abnormal device operational state exists with respect to the first device, the second device, the third device, or at least one of the plurality of circuit interrupting devices, wherein upon determining the

::ODMA\PCDOCS\BROUSE\698606\1 10 presence of an abnormal device operational state a first protection scheme is initiated with respect to the first electric energy distribution network and steps (d) - (h) are repeated until an abnormal device operation state is determined not to exist with respect to the first device, the second device, the third device, and the plurality of circuit interrupting devices;

(a) providing a first electric energy distribution network for distributing electric energy to a plurality of end users comprising: a first device, wherein the first device supplies electric energy generated from a generation facility to the first electric energy distribution network so as to establish an electrical connection;

::ODMA\PCDOCS\BROUSE\698606\1 γ γ a second device, wherein the second device comprises a circuit breaker device that is operable to establish and break the electrical connection between the first device and the first electric energy distribution network, wherein the second device is downstream from the first device and upstream from a plurality of circuit interrupting devices; the plurality of circuit interrupting devices, wherein the plurality of circuit interrupting devices are upstream from the plurality of end users and a third device; and, the third device, wherein the third device is a normal open point that interconnects the first electric energy distribution network to a second electric energy distribution network; and, operatively coupling the first device, the second device, the third device, and each of the plurality of circuit interrupting devices to communicate with a plurality of control units, wherein the first device, the second device, the third device, and each of the plurality of circuit interrupting devices are coupled to a distinct control unit that comprises the plurality of control units, and each of the distinct control units are operatively coupled to communicate with the other distinct control units;

(g) populating a decision table with data indicative of the operational state, whether a fault condition has occurred, and whether there is a voltage present across the

::ODMA\PCDOCS\BROUSE\698606\1 γχ first device, the second device, the third device, and each of the plurality of circuit interrupting devices;

::ODMA\PCDOCS\BROUSE\698606\1 13 (a) providing a first electric energy distribution network for distributing electric energy to a plurality of end users comprising: a first device, wherein the first device supplies electric energy generated from a generation facility to the first electric energy distribution network so as to establish an electrical connection; a second device, wherein the second device comprises a circuit breaker device that is operable to establish and break the electrical connection between the first device and the first electric energy distribution network, wherein the second device is downstream from the first device and upstream from a plurality of circuit interrupting devices; the plurality of circuit interrupting devices, wherein the plurality of circuit interrupting devices are upstream from the plurality of end users and a third device; and, the third device, wherein the third device is a normal open point that interconnects the first electric energy distribution network to a second electric energy distribution network; operatively coupling the first device, the second device, the third device, and each of the plurality of circuit interrupting devices to communicate with a plurality of control units, wherein the first device, the second device, the third device, and each of the plurality of circuit interrupting devices are coupled to a distinct control unit that comprises the plurality of control units, and each of the distinct control units are operatively coupled to communicate with the other distinct control units; and, displaying the decision table on a plurality of display devices wherein each of the plurality of display devices corresponds to one of the plurality of control units;

(d) detecting a device operational state of the first device, the second device, the third device, and the plurality of circuit interrupting devices; (e) detecting whether a fault condition occurred downstream from the first device, the second device, the third device, or the plurality of circuit interrupting devices

::ODMA\PCDOCS\BROUSE\698606\1 J 4 beginning with a normal open point of the second electric energy distribution network and progressing to the third device in the upstream direction;

(k) analyzing the decision table to determine the presence of a voltage across the normal open point of the second electric energy distribution network, wherein the method is terminated if a voltage is determined to not be present across the normal open point of the second electric energy distribution network; (1) analyzing the decision table to determine the presence of a voltage across each of the plurality of circuit interrupting devices;

::ODMA\PCDOCS\BROUSE\698606\1 15 (m) opening one of the plurality of circuit interrupting devices upon detecting that a voltage is not present across the respective plurality of circuit interrupting devices.

(a) providing a first electric energy distribution network for distributing electric energy to a plurality of end users comprising: a first device, wherein the first device supplies electric energy generated from a generation facility to the first electric energy distribution network so as to establish an electrical connection; a second device, wherein the second device comprises a circuit breaker device that is operable to establish and break the electrical connection between the first device and the first electric energy distribution network, wherein the second device is downstream from the first device and upstream from a plurality of circuit interrupting devices; the plurality of circuit interrupting devices, wherein the plurality of circuit interrupting devices are upstream from the plurality of end users and a third device; and, the third device, wherein the third device is a normal open point that interconnects the first electric energy distribution network to a second electric energy distribution network; and, operatively coupling the first device, the second device, the third device, and each of the plurality of circuit interrupting devices to communicate with a control unit, wherein the control unit receives a signal transmitted by the first device, the second device, the third device, and each of the plurality of circuit interrupting devices from which the operational state of the respective device may at least be partially determined;

(c) detecting the occurrence of the initiating trigger within the first electric energy distribution network; (d) detecting a device operational state of the first device, the second device, the third device, and the plurality of circuit interrupting devices;

::ODMA\PCDOCS\BROUSE\698606\1 16 (e) detecting whether a fault condition occurred downstream from the first device, the second device, the third device, or the plurality of circuit interrupting devices beginning with a normal open point of the second electric energy distribution network and progressing to the third device in the upstream direction; (f) detecting the presence of a voltage across the first device, the second device, the third device, and the plurality of circuit interrupting devices;

(g) populating a decision table with data indicative of the operational state, whether a fault condition has occurred, and whether there is a voltage present across the first device, the second device, the third device, and each of the plurality of circuit interrupting devices;

(i) analyzing the decision table to determine the presence of a fault condition exists with respect to the first device, the second device, the third device, or at least one of the plurality of circuit interrupting devices; wherein upon determining the presence of a fault condition the device immediately upstream from the fault condition is determined to be a faulted device and the faulted device and the device immediately downstream from the faulted device are opened; (j) analyzing the decision table to determine the presence of a voltage across the first device, wherein the method is terminated if a voltage is determined to not be present across the first device;

::ODMA\PCDOCS\BROUSE\698606\1 17 (1) analyzing the decision table to determine the presence of a voltage across each of the plurality of circuit interrupting devices;

According to one embodiment of the invention, a method for isolating disturbances to a electric energy distribution system may comprise the steps of:

(a) distributing electrical energy throughout a first circuit, wherein the first circuit comprises an electric energy supply device, a circuit breaker device, and a plurality of circuit interrupting devices, wherein the circuit breaker device is located downstream from the electric energy supply device and upstream from the plurality of circuit interrupting devices;

(b) providing electrical energy to a plurality of end users, wherein at least one of the plurality of end users is located downstream from each of the plurality of circuit interrupting devices;

(c) populating a decision table with a first set of values indicative of the current operational status of the electric energy supply device, the circuit breaker device, and the plurality of circuit interrupting devices, wherein the first set of values are based on a first plurality of inputs received by a control unit prior to detecting the occurrence of an initiating trigger;

(d) detecting the occurrence of the initiating trigger within the first circuit;

(e) re-populating the decision table with a second set of values indicative of the current operational status of the electric energy supply device, the circuit breaker device, and the plurality of circuit interrupting devices, wherein the second set of values are based on a second plurality of inputs received by the control unit subsequent to detecting the occurrence of the initiating trigger;

(f) analyzing the second set of values to determine the location of the initiating trigger with respect to at least one of the plurality of circuit interrupting devices, the circuit breaker device, or the electric energy supply device.

::ODMA\PCDOCS\BROUSE\698606\1 18 According to one embodiment of the invention, a method for isolating disturbances to a electric energy distribution system may comprise the steps of:

(b) providing electrical energy to a plurality of end users, wherein at least one of the plurality of end users is located downstream from each of the plurality of circuit interrupting devices; and, monitoring the first circuit for the occurrence of the initiating trigger;

(a) distributing electrical energy throughout a first circuit, wherein the first circuit comprises an electric energy supply device, a circuit breaker device, and a plurality of circuit interrupting devices, wherein the circuit breaker device is located downstream

::ODMA\PCDOCS\BROUSE\698606\1 19 from the electric energy supply device and upstream from the plurality of circuit interrupting devices;

(b) providing electrical energy to a plurality of end users, wherein at least one of the plurality of end users is located downstream from each of the plurality of circuit interrupting devices; and, operatively coupling the electric energy supply device, the circuit breaker device, and the plurality of circuit interrupting devices to communicate with a common control unit;

(d) detecting the occurrence of the initiating trigger within the first circuit; (e) re-populating the decision table with a second set of values indicative of the current operational status of the electric energy supply device, the circuit breaker device, and the plurality of circuit interrupting devices, wherein the second set of values are based on a second plurality of inputs received by the control unit subsequent to detecting the occurrence of the initiating trigger; (f) analyzing the second set of values to determine the location of the initiating trigger with respect to at least one of the plurality of circuit interrupting devices, the circuit breaker device, or the electric energy supply device.

::ODMA\PCDOCS\BROUSE\698606\1 20 (b) providing electrical energy to a plurality of end users, wherein at least one of the plurality of end users is located downstream from each of the plurality of circuit interrupting devices;

(c) populating a decision table with a first set of values indicative of the current operational status of the electric energy supply device, the circuit breaker device, and the plurality of circuit interrupting devices, wherein the first set of values are based on a first plurality of inputs received by a control unit prior to detecting the occurrence of an initiating trigger; and, displaying the decision table on a display device, wherein the display device is operatively coupled to communicate with the control unit;

According to one embodiment of the invention, a method for isolating disturbances to an electric energy distribution system may comprise the steps of:

(a) providing an electric distribution system comprising a first electric energy distribution circuit and a second electric energy distribution circuit, wherein the first electric energy distribution circuit and the second electric energy distribution circuit each comprise a plurality of electrical devices;

(b) detecting the occurrence of an initiating trigger within the first electric energy distribution circuit or the second electric energy distribution circuit;

(c) populating a first decision table and a second decision table with data indicative of the operation status of the plurality of electrical devices comprising the first

::ODMA\PCDOCS\BROUSE\698606\1 21 electric energy distribution circuit and the second electric energy distribution circuit respectively;

(d) analyzing the first decision table and the second decision table to determine the location of the initiating trigger.

(c) populating a first decision table and a second decision table with data indicative of the operation status of the plurality of electrical devices comprising the first electric energy distribution circuit and the second electric energy distribution circuit respectively; and, populating a first column of the first decision table and the second decision table with data at least partially based on a first signal transmitted from each electrical device comprising the first electric energy distribution circuit and the second electric energy distribution circuit respectively;

::ODMA\PCDOCS\BROUSE\698606\1 22 (b) detecting the occurrence of an initiating trigger within the first electric energy distribution circuit or the second electric energy distribution circuit;

(c) populating a first decision table and a second decision table with data indicative of the operation status of the plurality of electrical devices comprising the first electric energy distribution circuit and the second electric energy distribution circuit respectively; populating a first column of the first decision table and the second decision table with data at least partially based on a first signal transmitted from each electrical device comprising the first electric energy distribution circuit and the second electric energy distribution circuit respectively; and, restarting the method for isolating disturbances to an electric energy distribution system if the first column is populated with a first signal indicating that the respective electrical device is not operating properly;

(b) detecting the occurrence of an initiating trigger within the first electric energy distribution circuit or the second electric energy distribution circuit; (c) populating a first decision table and a second decision table with data indicative of the operation status of the plurality of electrical devices comprising the first electric energy distribution circuit and the second electric energy distribution circuit respectively; and, populating a second column of the first decision table and the second decision table with data indicative of the presence of a fault condition downstream from each of

::ODMA\PCDOCS\BROUSE\698606\1 23 the plurality of electrical devices comprising the first electric energy distribution circuit and the second electric energy distribution circuit respectively;

(c) populating a first decision table and a second decision table with data indicative of the operation status of the plurality of electrical devices comprising the first electric energy distribution circuit and the second electric energy distribution circuit respectively; populating a second column of the first decision table and the second decision table with data indicative of the presence of a fault condition downstream from each of the plurality of electrical devices comprising the first electric energy distribution circuit and the second electric energy distribution circuit respectively; and, analyzing the first decision table and the second decision table to determine the location of the initiating trigger, wherein the first decision table is analyzed beginning with a first normal point located within the second electric energy distribution circuit and then proceeding in an upstream direction, and the second decision table is analyzed beginning with a second normal point located with the first electric energy distribution circuit and then proceeding in an upstream direction, and the initiating trigger is a fault condition;

::ODMA\PCDOCS\BROUSE\698606\1 24 According to one embodiment of the invention, a method for isolating disturbances to an electric energy distribution system may comprise the steps of:

(c) populating a first decision table and a second decision table with data indicative of the operation status of the plurality of electrical devices comprising the first electric energy distribution circuit and the second electric energy distribution circuit respectively; and, populating a third column of the first decision table and the second decision table with data indicative of a voltage present with respect to each of the plurality of electrical devices comprising the first electric energy distribution circuit and the second electric energy distribution circuit respectively;

(c) populating a first decision table and a second decision table with data indicative of the operation status of the plurality of electrical devices comprising the first electric energy distribution circuit and the second electric energy distribution circuit respectively; and,

::ODMA\PCDOCS\BROUSE\698606\1 25 populating a third column of the first decision table and the second decision table with data indicative of a voltage present with respect to each of the plurality of electrical devices comprising the first electric energy distribution circuit and the second electric energy distribution circuit respectively; (d) analyzing the first decision table and the second decision table to determine the location of the initiating trigger; and, analyzing the first decision table and the second decision table to determine the location of the initiating trigger, wherein the first decision table is analyzed beginning with a first electric energy supply device located within the first electric energy distribution circuit followed by analyzing a first normal point located within the second electric energy distribution circuit and then proceeding in an upstream direction, and the second decision table is analyzed beginning with a second electric energy supply device located within the second electric energy distribution circuit followed by analyzing a second normal point located within the first electric energy distribution circuit and then proceeding in an upstream direction, and the initiating trigger is a loss of voltage condition.

One advantage of this invention is that upon the invention minimizes the number of end users who experience a disruption in electric service upon detection of an initiating trigger.

Still other benefits and advantages of the invention will become apparent to those skilled in the art to which it pertains upon a reading and understanding of the following detailed specification.

III. Brief Description of the Drawings

The invention may take physical form in certain parts and arrangement of parts, a preferred embodiment of which will be described in detail in this specification and illustrated in the accompanying drawings which form a part hereof and wherein:

::ODMA\PCDOCS\BROUSE\698606\1 26 FIGURE 1 shows a perspective schematic illustration of a generation facility, a transmission network, and a first electric energy distribution network according to an embodiment of the present invention; FIGURE 2 shows a schematic illustration of a first electric energy distribution network according to an embodiment of the present invention;

FIGURE 3 shows a schematic illustration of a first electric energy distribution network according to an embodiment of the present invention;

FIGURE 4 shows a decision table in accordance with an embodiment of the present invention;

FIGURE 5 a shows a partial flow diagram illustrating a method according to an embodiment of the present invention; and,

FIGURE 5b is a continuation of the flow diagram shown in FIGURE 5 a.

IV. Detailed Description of the Invention

Referring now to the drawings wherein the showings are for purposes of illustrating embodiments of the invention only and not for purposes of limiting the same, FIGURE 1 shows a schematic illustration of a first electric energy distribution network 10, also referred to as Circuit 1, according to one embodiment of the present invention. Furthest upstream in first electric energy distribution network 10 is an electric energy supply device 12, labeled Device 01. The electric energy supply device 12 may supply electric energy conducted from a power plant or generation facility 1 to the first electric energy distribution network 10. Generally, the generation facility 1 comprises an electrical generator device 3, such as a steam or gas turbine, a nuclear reactor, or a hydroelectric dam apparatus, that generates electric energy. The electric energy may then enter a transmission substation 4 located at the generation facility 1. The transmission substation 4 may utilize step-up transformers (not shown) to transform the voltage of the electric energy from the electrical generator device 3 up to extremely high voltages that may range from about 155,000 volts to about 765,000 volts. The electric energy may then be transmitted across a transmission grid or network 2 to be at least partially

::ODMA\PCDOCS\BROUSE\698606\1 27 received by the first electric energy distribution network 10 as is well known in the art. Due to the generation facility 1 being the source of the electric energy, the electric energy supply device 12 is considered to be the furthermost "upstream" component in the first electric energy distribution network 10.

With reference now to FIGURES 1 and 2, in one embodiment of the invention, the electric energy may be distributed throughout the first electric energy distribution network 10 by passing first through the electric energy supply device 12 prior to being transmitted "downstream" through the various other components comprising the first electric energy distribution network 10 as described below. The electric energy supply device 12 may comprise a power substation having step-down transformers 12a to step transmission voltages down to distribution voltages that may be less than about 10,000 volts. Additionally, the electric supply device 12 may comprise a bus device 12b for splitting or distributing the electric energy in multiple directions. The upstream and downstream directions relative to the electric energy supply device 12, are indicated by arrows 11 and 13, respectively (as shown in FIGURE 2). Further, devices positioned downstream from the electric energy supply device 12 may be referred to as being upstream or downstream relative to other devices comprising the first electric energy distribution network 10 based on the relative electrical position of the devices with respect to the electric energy supply device 12 and a respective load or end user to which the electric energy is to be ultimately supplied. For example, Device 05 can be considered downstream of Device 04 in the first electric energy distribution network 10 under normal operating conditions because Device 05 is further along the conductive path away from the generation facility 1, and therefore the electric energy supply device 12, (i.e., downstream) than Device 04.

With reference now to FIGURES 1-2, in one embodiment of the invention, the first electric energy distribution network 10 may comprise the electric supply device 12 (Device 01) and a circuit breaker device 14, (labeled as Device 02). The circuit breaker device 14 (Device 02) may comprise a conventional circuit breaker, a switch, or a combination of circuit breakers and switches. The circuit breaker device 14 may detect

::ODMA\PCDOCS\BROUSE\698606\1 28 current overload conditions and may be operable to establish and break the electrical connection between the electric supply device 12 (Device 01) and the other components of the first electric energy distribution network 10 that are located downstream from the electric energy supply device 12 and the circuit breaker device 14. For example, in one embodiment of the invention, the circuit breaker device 14 may be closed to conduct electric from the electric energy supply device 12 (Device 01) to one or more downstream devices. Under normal operating conditions, the opening of the circuit breaker device 14 (Device 02) may isolate all of the downstream devices in the electric energy distribution network 10 (Circuit 1), i.e., Device 03 through Device 09, from the electric energy supply device 12 (Device 01).

With reference now to FIGURES 1-2, the first electric energy distribution network 10 may comprise the electric supply device 12, the circuit breaker device 14, and a plurality of circuit interrupter devices 16. In one embodiment of the invention, the plurality of circuit interrupter devices 16 may comprise a first circuit interrupter device 18, a second circuit interrupter device 20, a third circuit interrupter device 22, a fourth circuit interrupter device 24, a fifth circuit interrupter device 26, and a sixth circuit interrupter device 28 (also referred to as Device 03 through Device 08). The plurality of circuit interrupter devices 16 may each allow electric energy to be distributed in a downstream direction with respect to the particular circuit interrupter device to a plurality of end users 19, 21, 23, 25, 27, 29 respectively. Each of the plurality of circuit interrupter devices 16 may be independently selected from the group consisting of a recloser, sectionalizer, switch, or any other type of circuit interrupter device. Alternatively, any or all of the plurality of circuit interrupter devices 16 may comprise a plurality of circuit interrupter devices operatively coupled to each other.

A recloser (also referred to as an auto-recloser) is a pole-mounted circuit interrupter device that is sensitive to fault conditions and that is operatively coupled to, and in electrical communication with, overhead distribution lines conducting electric energy. A fault condition may comprise an overcurrent or undercurrent condition in the distribution lines, typically caused when an undesirable conductive pathway is

::ODMA\PCDOCS\BROUSE\698606\1 29 established between a distribution line and ground or another conductive member. Overhead distribution lines may be subject to transient fault conditions. The transient fault condition may be an overcurrent condition of short duration that may be caused by lightening strikes, wind-borne debris, or animals such as squirrels climbing on or across the distribution line. When the recloser senses a fault condition, it automatically opens (i.e., establishes an open circuit), thereby isolating any downstream devices. After a predetermined period, the recloser closes, without manual operator intervention, to reestablish the closed circuit. If the recloser senses or detects that a fault condition is still present, the recloser will once again open and close thereby repeating the process. If the recloser senses or detects that a fault condition is still present after a predetermined number of re-closings or "shots," the recloser will remain open, thereby interrupting the flow of electric energy until the recloser is reset manually. Only devices and end users downstream of an open recloser will experience an interruption of electric energy service.

A sectionalizer is another device designed to protect the supply of electric energy from an outage condition when the flow of electric energy is interrupted. A sectionalizer may be used in conjunction with other circuit interrupter devices such as a circuit breaker or a recloser. The sectionalizer may be a pole-mounted device attached to overhead distribution lines that is sensitive to interruptions of current flow in those overhead distribution lines. The sectionalizer may act as a type of bypass switch for sections of a distribution network experiencing a fault condition. Upon a circuit breaker device or a recloser opening, thereby preventing the electric energy from being distributed downstream from the open device, the sectionalizer may allow the electric energy to be distributed along a parallel conductive pathway that allows the electric energy to be bypass the section of the distribution network experiencing the fault condition while still being distributed to other portions of the network. The sectionalizer may, therefore, serve to isolate a section of the distribution line affected by an abnormal current level while allowing the remainder of the circuit to remain energized.

A switch is a general term used herein to refer to any other device for making, breaking or changing connections within an electric circuit. The plurality of circuit

::ODMA\PCDOCS\BROUSE\698606\1 30 interrupting devices 16 may be considered to be local switching devices in order to clearly describe the present invention. Each of the plurality of circuit interrupting devices 16 may operate to isolate a local portion of the first electric energy distribution network 10 located downstream from the circuit breaker device 14.

The first electric energy distribution network 10 may comprise a normal open point 30 (also referred to as Device 09). The normal open point 30 may allow for the interconnecting of two or more electric energy distribution networks that may together comprise separate components of a common electric energy distribution network. The normal open point 30 (Device 09) may comprise a connecting point that may function as a "bridge" during an interruption of the flow of electric energy from the electric energy supply device 12 of the first electric energy distribution network 10. In one embodiment of the invention, the normal open point 30 may comprise a switchgear or a transformer. Thus, in the event that the supply of electric energy from the electric energy supply device 12 (Device 01) in the first electric energy distribution network 10 (Circuit 1) is interrupted, electric energy can be supplied by the normal open point 30 (Device 09). In such cases, the upstream directions and the downstream directions, shown in FIGURE 2 by arrows 11', 13' respectively, are reversed. Therefore, the upstream direction may be considered to be in the direction toward the device supplying electric energy.

With reference now to FIGURE 3, is a schematic illustration of a second electric energy distribution network 40 according to one embodiment of the present invention is shown. The second electric energy distribution network 40 may be considered to be analogous to the first electric energy distribution network 10 for purposes of describing the present invention. The first electric distribution network 10 (Circuit 1) and the second electric distribution network 40 (Circuit 2) may be considered to be interconnected, meaning that Device 09 of Circuit 1 corresponds to Device 10' of Circuit 2, and Device 10 of Circuit 1 corresponds to Device 09' of Circuit 2. In other words, Circuit 1 starts at the Device 01, the supply, and ends with the Normal Open point 30 of Device 09. Device 10 is shown in FIGURE 2 as the Normal Open point 30' of Device 09' of Circuit 2 in FIGURE 3.

::ODMA\PCDOCS\BROUSE\698606\1 31 According to one embodiment of the invention, each device comprising the first electric distribution network 10 and each device comprising the second electric distribution network 40 may be operatively coupled to communicate with a first control unit 32 and a second control unit 34 respectively. The control units 32, 34 may each comprise a single conventional computer that includes many of the features commonly included in a conventional personal computer. Each device comprising the first electric distribution network 10 and each device comprising the second electric distribution network 40 may be operatively coupled to communicate with their respective common control unit 32, 34. The control units 32, 34 may be located at a central or main location within the respective electric energy distribution network 10, 40. According to another embodiment of the invention, the control units 32, 34 may comprise a plurality of conventional computers wherein each device is operatively coupled to communicate with a separate control unit. The separate control units may be operatively coupled to communicate with each other and may allow an operator to affect changes within the respective electric energy distribution network. The components of the control units 32, 34 may operate according to commands contained in computer-executable instructions, or software, stored in a computer-accessible memory operatively coupled via a data bus with the control units 32,34. The control units 32, 34 may be adapted to carry out the method steps described herein that are to be performed in response to the execution of the computer-executable instructions.

With reference now to FIGURES 2 and 4, a decision table 45 including the devices comprising the first electric energy distribution network 10 and the normal open point 30' of the second electric energy distribution network 40. In practice, a decision table such as that shown in FIGURE 4 can be created for each circuit comprising any specific electric energy distribution network. And, although a particular definition of zeros and ones has been shown to represent various conditions of the first electric energy distribution network 10, the present invention can utilize any combination that can serve to distinguish between such various conditions. The decision table 45 may be electronic,

::ODMA\PCDOCS\BROUSE\698606\1 32 and may be displayed by a display device that is operatively coupled to the control device 32, 34.

The method of the present invention and the analysis of the data in the decision table 45 shown in FIGURE 4 will also be described with reference to the flow diagram of FIGURES 5a and 5b. In FIGURES 5a and 5b, the method of isolating a disturbance to the first electric energy distribution system 10 may begin with the occurrence of an initiating trigger. An initiating trigger can be a fault condition occurring within the first electric energy distribution system 10 (Circuit 1), a loss of voltage within the first electric energy distribution system 10 (Circuit 1), or a combination thereof. In one embodiment of the invention, the specific circuit within an electric energy distribution system in which an initiating trigger has been detected dictates the decision table that will be analyzed to locate and isolate the disturbance to the electric energy distribution system. For example, if the initiating trigger was detected in the first electric energy distribution system 10 (Circuit 1), then the Circuit 1 decision table, decision table 45, which is shown in FIGURE 4, is analyzed by the control unit 32 as described below.

With reference now to FIGURES 4, 5a, 5b, once an initiating trigger has been detected, the decision table 45 of FIGURE 4 is populated at step 50 with data indicative of the current operational status of each device comprising the first electric energy distribution network 10 (Circuit 1). In one embodiment of the invention, the step of populating the decision table 45 may include populating an "Abnormal Operation" column 46, a "Fault" column 47, and a "Has Voltage" column 48. The Abnormal Operation column 46 is populated with a zero (0) based on a signal transmitted for each device comprising the first electric energy distribution network 10 (Circuit 1) that is operating properly. For example, if a repair crew is servicing a line downstream of Device 05, the repair crew would manually disconnect the downstream distribution line from the electric energy distribution system by opening Device 05. In response, the Abnormal Operation column 46 would be populated with a one (1) for Device 05, indicating that Device 05 is not operating normally, or is not in its normal, closed, position, which is indicated in the "Normal Condition" column 44. If, at step 54 in

::ODMA\PCDOCS\BROUSE\698606\1 33 FIGURE 5 a it is determined that any of the devices comprising the first electric energy distribution network 10 (Circuit 1) are not operating normally, as indicated by a one (1) in the Abnormal Operation column 46, then the method restarts and protection of the electric energy distribution system 10 reverts to any protection scheme until it is determined at step 54 that all devices are operating normally. In one embodiment of the invention, the electric energy distribution system 10 may revert to any protection scheme that comprises utilizing a sectionalizer to isolate the device while still distributing the electric energy to the remaining portions of the electric energy distribution network 10.

If at step 54 it is determined that all devices comprising the first electric energy distribution network 10 (Circuit 1) are operating normally, then the method includes a scan of the Fault column 47 beginning with the normal open point 30' of the second electric energy distribution system 40 (Device 10) and progressing in the upstream direction toward the electric energy supply device 12 (Device 01) of the first electric energy distribution network 10 at step 58. According to one embodiment of the invention, a zero (0) in the Fault Column 47 in FIGURE 4 may be used indicate no fault and a one (1) may be used to indicate the presence of a fault condition, but the present invention can utilize any definitions to differentiate between a fault and no fault chosen with sound judgment by a person of ordinary skill in the art. If, at step 62 it is determined that a fault condition has been detected by observing a one (1) in the Fault column 47 at a device, such as Device 05 for example, then Device 05 and the immediately downstream device, Device 06 in the present example, will be opened at step 66.

If no fault is detected at step 62, then it is determined at step 70 whether voltage is present at the electric energy supply device 12 (Device 01). If there is not a voltage detected across the electric energy supply device 12, i.e., a zero is detected for Device 01, then the isolation method of the present invention is terminated due to a circuit- wide loss of supply voltage. If, however, at step 70 it is determined that the supply voltage is present, then it is determined at step 74 whether voltage is present at Device 10. If not, the method is terminated. But if so, the Has Voltage column 48 for Circuit 1 is scanned

::ODMA\PCDOCS\BROUSE\698606\1 34 beginning with the normal open point 30 (Device 09) and continuing in an upstream direction at step 78.

The scan at step 78 may be attempting to detect a state change, i.e., a change from a zero (0) at one device to a one (1) at the immediately upstream device with respect to the immediately downstream device. If such a state change is detected at step 82, then the device for which a zero (0) was detected in the Has Voltage column 48 is opened at step 86, and the method completed.

Although the number of devices comprising the first electric energy distribution network 10 (Circuit 1) and the second electric energy distribution network 40 (Circuit 2) is described herein and shown in the FIGURES to consist often (10) devices, the first electric energy distribution network 10 (Circuit 1) and the second electric energy distribution network 40 (Circuit 2) may comprise any number of devices chosen with sound judgment by one of ordinary skill in the art.

The embodiments have been described, hereinabove. It will be apparent to those skilled in the art that the above methods and apparatuses may incorporate changes and modifications without departing from the general scope of this invention. It is intended to include all such modifications and alterations in so far as they come within the scope of the appended claims or the equivalents thereof.

Having thus described the invention, it is now claimed:

::ODMA\PCDOCS\BROUSE\698606\1 35

Claims

I/WE CLAIM:

1. A method for isolating disturbances to a power distribution system characterized by: (a) providing a first electric energy distribution network (10) for distributing electric energy to a plurality of end users comprising: a first device (12), wherein the first device (12) supplies electric energy generated from a generation facility (1) to the first electric energy distribution network (10) so as to establish an electrical connection; a second device (14), wherein the second device (14) comprises a circuit breaker device (14) that is operable to establish and break the electrical connection between the first device (12) and the first electric energy distribution network (10), wherein the second device (14) is downstream from the first device (12) and upstream from a plurality of circuit interrupting devices (16); the plurality of circuit interrupting devices (16), wherein the plurality of circuit interrupting devices (16) are upstream from the plurality of end users and a third device (30); and, the third device (30), wherein the third device (30) is a normal open point that interconnects the first electric energy distribution network (10) to a second electric energy distribution network (40);

(b) monitoring the first electric energy distribution network (10) for the occurrence of an initiating trigger;

(c) detecting the occurrence of the initiating trigger within the first electric energy distribution network (10); (d) detecting a device operational state of the first device (12), the second device

(14), the third device (30), and the plurality of circuit interrupting devices (16);

(e) detecting whether a fault condition occurred downstream from the first device (12), the second device (14), the third device (30), or the plurality of circuit interrupting devices (16) beginning with a normal open point (30') of the second electric energy distribution network (40) and progressing to the third device (30) in the upstream direction;

::ODMA\PCDOCS\BROUSE\698606\1 36 (f) detecting the presence of a voltage across the first device (12), the second device (14), the third device (30), and the plurality of circuit interrupting devices (16);

(g) populating a decision table (45) with data indicative of the operational state, whether a fault condition has occurred, and whether there is a voltage present across the first device (12), the second device (14), the third device (30), and each of the plurality of circuit interrupting devices (16);

(h) analyzing the decision table (45) to determine if an abnormal device operational state exists with respect to the first device (12), the second device (14), the third device (30), or at least one of the plurality of circuit interrupting devices (16), wherein upon determining the presence of an abnormal device operational state a first protection scheme is initiated with respect to the first electric energy distribution network (10) and steps (d) - (h) are repeated until an abnormal device operation state is determined not to exist with respect to the first device (12), the second device (14), the third device (30), and the plurality of circuit interrupting devices (16); (i) analyzing the decision table (45) to determine the presence of a fault condition exists with respect to the first device (12), the second device (14), the third device (30), or at least one of the plurality of circuit interrupting devices (16); wherein upon determining the presence of a fault condition the device immediately upstream from the fault condition is determined to be a faulted device and the faulted device and the device immediately downstream from the faulted device are opened;

(j) analyzing the decision table (45) to determine the presence of a voltage across the first device (12), wherein the method is terminated if a voltage is determined to not be present across the first device (12);

(k) analyzing the decision table (45) to determine the presence of a voltage across the normal open point of the second electric energy distribution network, wherein the method is terminated if a voltage is determined to not be present across the normal open point (30') of the second electric energy distribution network (40);

(1) analyzing the decision table to determine the presence of a voltage across each of the plurality of circuit interrupting devices (16);

::ODMA\PCDOCS\BROUSE\698606\1 37 (m) opening one of the plurality of circuit interrupting devices (16) upon detecting that a voltage is not present across the respective plurality of circuit interrupting devices (16).

2. The method of claim 1, wherein step (a) is further characterized by: independently selecting the plurality of circuit interrupting devices (16) from the group consisting of: a recloser, a sectionalizer, or a switch.

3. The method of claim 1, wherein step (a) is further characterized by: operatively coupling the first device (12), the second device (14), the third device

(30), and each of the plurality of circuit interrupting devices (16) to communicate with a common control unit (32).

4. The method of claim 3, wherein the step of operatively coupling the first device (12), the second device (14), the third device (30), and each of the plurality of circuit interrupting devices (16) to communicate with a control unit (32), is further characterized by: displaying the decision table (45) on a display device, wherein the display device is operatively coupled to the control unit.

5. The method of claim 1, wherein step (a) is further characterized by: operatively coupling the first device (12), the second device (14), the third device

(30), and each of the plurality of circuit interrupting devices (16) to communicate with a plurality control units (32), wherein the first device (12), the second device (14), the third device (30), and each of the plurality of circuit interrupting devices (16) are each coupled to a distinct control unit (32) that comprises the plurality of control units (32), and each of the distinct control units (32) are operatively coupled to communicate with the other distinct control units (32).

6. The method of claim 5, wherein the step of, operatively coupling the first device (12), the second device (14), the third device (30), and each of the plurality of

::ODMA\PCDOCS\BROUSE\698606\1 38 circuit interrupting devices (16) to communicate with a plurality control units (32), wherein the first device (12), the second device (14), the third device (30), and each of the plurality of circuit interrupting devices (16) are each coupled to a distinct control unit (32) that comprises the plurality of control units (32), and each of the distinct control units (32) are operatively coupled to communicate with the other distinct control units (32), is further characterized by: displaying the decision table (45) on a plurality of display devices wherein each of the plurality of display devices corresponds to one of the plurality of control units (32).

7. The method of claim 1, wherein step (b) is further characterized by: operatively coupling the first device (12), the second device (14), the third device (30), and each of the plurality of circuit interrupting devices (16) to communicate with a control unit (32), wherein the control unit (32) receives a signal transmitted by the first device (12), the second device (14), the third device (30), and each of the plurality of circuit interrupting devices (16) from which the operational state of the respective device may at least be partially determined.

8. A method for isolating disturbances to a electric energy distribution system characterized by: (a) distributing electrical energy throughout a first circuit (10), wherein the first circuit (10) comprises an electric energy supply device (12), a circuit breaker device (14), and a plurality of circuit interrupting devices (16), wherein the circuit breaker device (14) is located downstream from the electric energy supply device (12) and upstream from the plurality of circuit interrupting devices (16); (b) providing electrical energy to a plurality of end users, wherein at least one of the plurality of end users is located downstream from each of the plurality of circuit interrupting devices (16);

(c) populating a decision table (45) with a first set of values indicative of the current operational status of the electric energy supply device (12) , the circuit breaker device (14), and the plurality of circuit interrupting devices (16), wherein the first set of

::ODMA\PCDOCS\BROUSE\698606\1 39 values are based on a first plurality of inputs received by a control unit (32) prior to detecting the occurrence of an initiating trigger;

(d) detecting the occurrence of the initiating trigger within the first circuit (10);

(e) re-populating the decision table (45) with a second set of values indicative of the current operational status of the electric energy supply device (12) , the circuit breaker device (14), and the plurality of circuit interrupting devices (16), wherein the second set of values are based on a second plurality of inputs received by the control unit (32) subsequent to detecting the occurrence of the initiating trigger;

(f) analyzing the second set of values to determine the location of the initiating trigger with respect to at least one of the plurality of circuit interrupting devices (16), the circuit breaker device (14), or the electric energy supply device (12).

9. The method of claim 8,wherein step (b) is further characterized by: monitoring the first circuit (10) for the occurrence of the initiating trigger.

10. The method of claim 8, wherein step (b) is further characterized by: operatively coupling the electric energy supply device (12) , the circuit breaker device (14), and the plurality of circuit interrupting devices (16) to communicate with a common control unit (32).

11. The method of claim 8, wherein step (b) is further characterized by: operatively coupling the electric energy supply device (12) , the circuit breaker device (14), and the plurality of circuit interrupting devices (16) to communicate with a plurality of control units (32).

12. The method of claim 8, wherein step (c) is further characterized by: displaying the decision table (45) on a display device, wherein the display device is operatively coupled to communicate with the control unit (32).

13. A method for isolating disturbances to an electric energy distribution system characterized by:

::ODMA\PCDOCS\BROUSE\698606\1 40 (a) providing an electric distribution system comprising a first electric energy distribution circuit (10) and a second electric energy distribution circuit (40), wherein the first electric energy distribution circuit (10) and the second electric energy distribution circuit (40) each comprise a plurality of electrical devices; (b) detecting the occurrence of an initiating trigger within the first electric energy distribution circuit (10) or the second electric energy distribution circuit (40);

(c) populating a first decision table (45) and a second decision table (45) with data indicative of the operation status of the plurality of electrical devices comprising the first electric energy distribution circuit (10) and the second electric energy distribution circuit (40) respectively;

(d) analyzing the first decision table (45) and the second decision table (45) to determine the location of the initiating trigger.

14. The method of claim 13, wherein step (c) is further characterized by: populating a first column (46) of the first decision table (45) and the second decision table (45) with data at least partially based on a first signal transmitted from each electrical device comprising the first electric energy distribution circuit (10) and the second electric energy distribution circuit (40) respectively.

15. The method of claim 14, wherein step (d) is further characterized by: restarting the method for isolating disturbances to an electric energy distribution system if the first column (46) is populated with a first signal indicating that the respective electrical device is not operating properly.

16. The method of claim 13, wherein step (c) is further characterized by: populating a second column (47) of the first decision table (45) and the second decision table (45) with data indicative of the presence of a fault condition downstream from each of the plurality of electrical devices comprising the first electric energy distribution circuit (10) and the second electric energy distribution circuit (40) respectively.

::ODMA\PCDOCS\BROUSE\698606\1 4 J

17. The method of claim 16, wherein step (d) is further characterized by: analyzing the first decision table (45) and the second decision table (45) to determine the location of the initiating trigger, wherein the first decision table (45) is analyzed beginning with a first normal point (30') located within the second electric energy distribution circuit (40) and then proceeding in an upstream direction, and the second decision table (45) is analyzed beginning with a second normal point (30) located within the first electric energy distribution circuit (10) and then proceeding in an upstream direction, and the initiating trigger is a fault condition.

18. The method of claim 13, wherein step (c) is further characterized by: populating a third column (48) of the first decision table (45) and the second decision table (45) with data indicative of a voltage present with respect to each of the plurality of electrical devices comprising the first electric energy distribution circuit (10) and the second electric energy distribution circuit (40) respectively.

19. The method of claim 18, wherein step (d) is further characterized by: analyzing the first decision table (45) and the second decision table (45) to determine the location of the initiating trigger, wherein the first decision table (45) is analyzed beginning with a first electric energy supply device (12) located within the first electric energy distribution circuit (10) followed by analyzing a first normal point (30') located within the second electric energy distribution circuit (40) and then proceeding in an upstream direction, and the second decision table (45) is analyzed beginning with a second electric energy supply device (12') located within the second electric energy distribution circuit (40) followed by analyzing a second normal point (30) located within the first electric energy distribution circuit (10) and then proceeding in an upstream direction, and the initiating trigger is a loss of voltage condition.

::ODMA\PCDOCS\BROUSE\698606\1 42