Patent Publication Number: US-11646603-B2

Title: Single phase fault isolation and restoration with loop avoidance for multiple tie-in devices

Description:
FIELD OF DISCLOSURE 
     Embodiments described herein relate to power distribution networks. More particularly, embodiments described herein relate to systems and methods for providing single phase fault isolation and restoration with loop avoidance in a power distribution network. 
     SUMMARY 
     Electric power distribution networks (sometimes referred to as “power distribution networks” or “distribution networks”) include fault monitoring equipment that identifies problems in the system and opens isolation devices to isolate the problems. Example problems with the distribution system include overcurrent faults, phase-to-phase faults, ground faults, etc. that may arise from various causes, such as equipment failure, weather-related damage to equipment, etc. Switching equipment is provided in the power distribution network to isolate the detected faults. In some instances, a fault may be detected by an isolation device that is not located closest to the fault. As a result, power may be interrupted for more customers than necessary. Various isolation devices attempt to reclose to restore power to non-affected portions of the power distribution network. Power distribution networks typically use three-phase transmission lines, and the isolation devices are controlled to isolate all three phases in response to a detected fault. Even in cases where a particular fault only involves one or two of the phases, power is interrupted for all customers on the affected transmission line. 
     Embodiments described herein provide, among other things, systems and methods for providing single phase fault isolation and restoration with loop avoidance in a power distribution network. 
     One embodiment includes a system for controlling a power distribution network providing power using a plurality of phases. The system includes an electronic processor configured to receive a first fault indication associated with a fault in the power distribution network from a first isolation device of a plurality of isolation devices. The electronic processor is configured to identify a first subset of the plurality of phases associated with the first fault indication and a second subset of the plurality of phases not associated with the first fault indication. The first subset and the second subset each include at least one member. The electronic processor is configured to identify a set of downstream isolation devices downstream of the fault. The electronic processor is configured to send a first open command to each member of the set of downstream isolation devices for each phase in the first subset. The electronic processor is configured to identify a plurality of tie-in isolation devices to be closed to restore power, each of the tie-in isolation devices being associated with one of the set of downstream isolation devices. Responsive to identifying a first potential loop configuration, for each of the plurality of tie-in devices, the electronic processor is configured to send a close command to the tie-in isolation device for each of the plurality of phases; and send a second open command to the associated downstream isolation device for each phase in the second subset. The electronic processor is configured to complete the sending of the close command and the second open command for each of the plurality of tie-in isolation devices prior to processing remaining ones of the plurality of tie-in isolation devices. 
     Another embodiment includes a method for controlling a power distribution network that provides power using a plurality of phases. The method includes receiving, via an electronic processor, a first fault indication associated with a fault in the power distribution network from a first isolation device of a plurality of isolation devices. The electronic processor identifies a first subset of the plurality of phases associated with the first fault indication and a second subset of the plurality of phases not associated with the first fault indication. The first subset and the second subset each include at least one member. The electronic processor identifies a set of downstream isolation devices downstream of the fault. The electronic processor sends a first open command to each member of the set of downstream isolation devices for each phase in the first subset. The electronic processor identifies a set of downstream isolation devices downstream of the fault. The electronic processor sends a first open command to each member of the set of downstream isolation devices for each phase in the first subset. The electronic processor identifies a plurality of tie-in isolation devices to be closed to restore power. Each of the tie-in isolation devices are associated with one of the set of downstream isolation devices. Responsive to identifying a first potential loop configuration, for each of the plurality of tie-in devices, the electronic processor sends a close command to the tie-in isolation device for each of the plurality of phases and sends a second open command to the associated downstream isolation device for each phase in the second subset. The electronic processor completes the sending of the close command and the second open command for each of the plurality of tie-in isolation devices prior to processing remaining ones of the plurality of tie-in isolation devices. 
     Other aspects of the disclosure will become apparent by consideration of the detailed description and accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a simplified block diagram of a system for controlling single phase fault isolation in a power distribution network, according to some embodiments. 
         FIG.  2    is a simplified diagram of a power distribution network, according to some embodiments. 
         FIG.  3    is a diagram of a switchgear system including an isolation device, according to some embodiments. 
         FIGS.  4 A- 4 F  are diagrams illustrating operation of the system of  FIG.  1    to handle a fault, according to some embodiments. 
         FIG.  5    is a flowchart of a method for operating the system of  FIG.  1    to handle a fault, according to some embodiments. 
         FIGS.  6 A- 6 E  are diagrams illustrating the operation of the system of  FIG.  1    to handle a loss of voltage fault, according to some embodiments. 
         FIG.  7    is a flowchart of a method for operating the system of  FIG.  1    to handle a loss of voltage fault, according to some embodiments. 
         FIGS.  8 A- 8 D  are diagrams illustrating the operation of the system of  FIG.  1    to perform a fault restoration operation that avoids loop configurations, according to some embodiments. 
         FIG.  9    is a flowchart of a method for operating the system of  FIG.  1    to perform a fault restoration operation that avoids loop configurations, according to some embodiments. 
         FIGS.  10 A- 10 G  are diagrams illustrating the operation of the system of  FIG.  1    to perform a fault restoration operation that avoids loop configurations with multiple tie-in isolation devices, according to some embodiments. 
         FIG.  11    is a flowchart of a method for operating the system of  FIG.  1    to perform a fault restoration operation that avoids loop configurations with multiple tie-in isolation devices, according to some embodiments. 
         FIGS.  12 A- 12 G  are diagrams illustrating the operation of the system of  FIG.  1    to avoid loop configurations, according to some embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     One or more embodiments are described and illustrated in the following description and accompanying drawings. These embodiments are not limited to the specific details provided herein and may be modified in various ways. Furthermore, other embodiments may exist that are not described herein. Also, the functionality described herein as being performed by one component may be performed by multiple components in a distributed manner. Likewise, functionality performed by multiple components may be consolidated and performed by a single component. Similarly, a component described as performing particular functionality may also perform additional functionality not described herein. For example, a device or structure that is “configured” in a certain way is configured in at least that way, but may also be configured in ways that are not listed. Furthermore, some embodiments described herein may include one or more electronic processors configured to perform the described functionality by executing instructions stored in non-transitory, computer-readable medium. Similarly, embodiments described herein may be implemented as non-transitory, computer-readable medium storing instructions executable by one or more electronic processors to perform the described functionality. As used herein, “non-transitory computer-readable medium” comprises all computer-readable media but does not consist of a transitory, propagating signal. Accordingly, non-transitory computer-readable medium may include, for example, a hard disk, a CD-ROM, an optical storage device, a magnetic storage device, a ROM (Read Only Memory), a RAM (Random Access Memory), register memory, a processor cache, or any combination thereof. 
     Also, the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. For example, the use of “including,” “containing,” “comprising,” “having,” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. The terms “connected” and “coupled” are used broadly and encompass both direct and indirect connecting and coupling. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings and can include electrical connections or couplings, whether direct or indirect. In addition, electronic communications and notifications may be performed using wired connections, wireless connections, or a combination thereof and may be transmitted directly or through one or more intermediary devices over various types of networks, communication channels, and connections. Moreover, relational terms such as first and second, top and bottom, and the like may be used herein solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. 
       FIG.  1    illustrates a system  100  for controlling a power distribution network  105 , according to some embodiments. In the example shown, the system  100  includes a server  110  communicating with entities in the power distribution network  105  over one or more communication networks  115 . In some embodiments, the system  100  includes fewer, additional, or different components than illustrated in  FIG.  1   . For example, the system  100  may include multiple servers  110 . The communication network  115  employs one or more wired or wireless communication sub-networks or links. Portions of the communication network  115  may be implemented using a wide area network, such as the Internet, a local area network, such as a Bluetooth™ network or Wi-Fi, and combinations or derivatives thereof. In some embodiments, components of the system  100  communicate through one or more intermediary devices not illustrated in  FIG.  1   . 
     The server  110  is a computing device that may serve as a centralized resource for controlling entities in the power distribution network  105 . As illustrated in  FIG.  1   , the server  110  includes an electronic processor  120 , a memory  125 , and a communication interface  130 . The electronic processor  120 , the memory  125  and the communication interface  130  communicate wirelessly, over one or more communication lines or buses, or a combination thereof. The server  110  may include additional components than those illustrated in  FIG.  1    in various configurations. The server  110  may also perform additional functionality other than the functionality described herein. Also, the functionality described herein as being performed by the server  110  may be distributed among multiple devices, such as multiple servers included in a cloud service environment. 
     The electronic processor  120  includes a microprocessor, an application-specific integrated circuit (ASIC), or another suitable electronic device for processing data. The memory  125  includes a non-transitory computer-readable medium, such as read-only memory (ROM), random access memory (RAM) (for example, dynamic RAM (DRAM), synchronous DRAM (SDRAM), and the like), electrically erasable programmable read-only memory (EEPROM), flash memory, a hard disk, a secure digital (SD) card, another suitable memory device, or a combination thereof. The electronic processor  120  is configured to access and execute computer-readable instructions (“software”) stored in the memory  125 . The software may include firmware, one or more applications, program data, filters, rules, one or more program modules, and other executable instructions. For example, the software may include instructions and associated data for performing a set of functions, including the methods described herein. For example, as illustrated in  FIG.  1   , the memory  125  may store instructions for executing a fault location, isolation, and restoration (FLISR) unit  135  to control entities in the power distribution network  105 . 
     The communication interface  130  allows the server  110  to communicate with devices external to the server  110 . For example, as illustrated in  FIG.  1   , the server  110  may communicate with entities in the power distribution network  105 . The communication interface  130  may include a port for receiving a wired connection to an external device (for example, a universal serial bus (USB) cable and the like), a transceiver for establishing a wireless connection to an external device (for example, over one or more communication networks  115 , such as the Internet, local area network (LAN), a wide area network (WAN), and the like), or a combination thereof. 
       FIG.  2    is a simplified diagram of the power distribution network  105 , according to some embodiments. In the example shown, the power distribution network  105  comprises sources, S 1 -S 3 , and isolation devices R 1 -R 14 . The sources S 1 -S 3  and isolation devices R 1 -R 14  are connected by transmission lines  200 . In general, the isolation devices R 1 -R 14  serve to segment the power distribution network  105  so that power is provided via a single source S 1 -S 3  and to isolate portions of the power distribution network  105  in response to identified faults. The isolation devices R 1 -R 14  may also be referred to as reclosers. Open transmission lines  200  are illustrated with dashed lines. An open diamond is used in the figures and placed adjacent an isolation device  305  (as noted, also illustrated in some cases as R 1 -R 14 ) isolating the transmission line  200  from a power source. In general, only one source S 1 -S 3  feeds a section of the power distribution network  105 . Certain isolation devices R 1 -R 14  are designated as tie-in isolation devices that allow a different source S 1 -S 3  to be tied into a section normally fed by a different source S 1 -S 3 . For example, the source S 2  feeds the transmission lines  200  associated with the isolation devices R 5 , R 14 , R 13 , R 12 . The isolation device R 12  is in an open state, and is a tie-in isolation device that may be closed to provide power from one of the other sources S 1 , S 3 . Similarly, isolation devices R 7 , R 9  are tie-in isolation devices associated with the source S 1 .  FIG.  2    illustrates the normal operating configuration of the power distribution network  105  with no faults. 
       FIG.  3    is a diagram of a switchgear system  300  including an isolation device  305 , according to some embodiments. As noted, the isolation device  305  may also be referred to as a recloser. Each of the isolation devices R 1 -R 14  in  FIG.  2    may be configured in a manner that is the same as or similar to the configuration of the isolation device  305 . In the example provided in  FIG.  3   , the isolation device  305  receives high voltage electrical power via a line connection  310  and delivers the high voltage electrical power via a load connection  315 . An interrupting mechanism  320  (for example, a vacuum interrupter) is electrically coupled between the line connection  310  and the load connection  315  to selectively interrupt current flow therebetween. The switchgear system  300  also includes a junction board  325  that is electrically coupled to the isolation device  305 . A controller  330  is electrically coupled to the junction board  325  via a control cable  335 . In  FIG.  3   , only one phase of the isolation device  305  is illustrated. For ease of description, the other two phases of the three-phase isolation device  305  are not shown or described in detail. However, the other two phases of the three-phase isolation device  305  may include similar components as shown in  FIG.  3   . For example, each of the other two phases may include an interrupting medium, line and load connections, and a junction board. The controller  330  may be connected to control all the junction boards  325 . 
     The isolation device  305  automatically tests the electrical line to identify a fault condition, and automatically opens the line if a fault is detected. In some embodiments, the isolation device  305  opens all three-phases in response to detecting a fault, for example, an overcurrent fault. The isolation device  305  may operate in a recloser mode or a one-shot mode. 
     In the recloser mode, the isolation device  305  determines whether the fault condition was only temporary and has resolved and automatically resets to close the line and restore electric power. Many trouble conditions on high voltage lines are temporary (for example, lightning, windblown tree branches, windblown transmission lines, animals, etc.), and will, by their nature, remove themselves from the transmission line if the power is shut off before permanent damage occurs. The isolation device  305  senses when trouble occurs and automatically opens to remove power. After a short delay, which may be recognized as or materialize as a lightbulb flicker, for example, the isolation device  305  recloses to restore power. However, if the trouble condition is still present, the isolation device  305  opens again. If the trouble condition persists for a predetermined number of times (for example, three), the isolation device  305  locks open and sends a fault notification via the controller  330  to a centralized controller, for example the server  110  of  FIG.  1    executing the FLISR unit  135 . Examples of long-lasting or permanent problem conditions include damaged or down transmission lines, and physical equipment failure or damage. 
     In the one-shot mode, the automatic recloser functionality of the isolation device  305  is disabled. If a fault condition is identified, the isolation device  305  locks open and sends a fault indication via the controller  330  without attempting to reclose. 
     Referring to  FIGS.  4 A- 4 F  and  FIG.  5   , the operation of the system of  FIG.  1    is illustrated for a fault.  FIGS.  4 A- 4 F  are diagrams illustrating the operation of the system of  FIG.  1    for a fault in a portion of the power distribution network  105  of  FIG.  2   , according to some embodiments.  FIG.  5    is a flowchart of a method  500  for operating of the system of  FIG.  1    for a fault, according to some embodiments. 
     In some embodiments, a lockout fault is a fault condition that causes the isolation device  305  identifying the condition to lock in an open state. Example lockout fault conditions include voltage faults, phase to phase faults, ground faults, etc. In some embodiments, the isolation device  305  signals a fault indication to the FLISR unit  135  of  FIG.  1    after attempting to reclose a predetermined number of times, as described above. 
     In some instances, the isolation device  305  that opens or trips is not the isolation device  305  closest to the fault. For example, the communication links between the isolation devices  305  and the FLISR unit  135  may have different latencies. For purposes of the following example, assume that a phase to phase fault is present between the R 14  isolation device  305  and the R 13  isolation device  305 .  FIG.  4 A  illustrates the power distribution network  105  prior to any automatic operations, with the fault illustrated between the R 14  and R 13  isolation devices  305 . 
     In response to the fault, the R 5  isolation device  305  locks open and sends a fault indication (in this example, as indicated by the “!” in the R 5  block). Referring to  FIG.  5   , a fault indication is received in the FLISR unit  135  (block  505 ), for example, from the R 5  isolation device  305 . In some embodiments, the FLISR unit  135  waits for a predetermined time interval (for example, 30 seconds) after receiving the fault indication before proceeding with restoration operations. As shown in  FIG.  4 B , the R 5  isolation device  305  is locked open for a first subset of the phases that includes the faulted phases, B and C. A second subset of the phases includes the non-faulted phase, A. 
     After receiving fault indication (block  505 ), the FLISR unit  135  attempts to identify the fault location by examining the fault states of other isolation devices downstream of the fault issuing R 5  isolation device  305 . Isolation devices  305  with asserted faults states are identified with “!” indicators, and isolation devices  305  with clear fault states are identified with “-” indicators (dashes) in  FIG.  4 B . In some embodiments, the isolation devices  305  send fault states at periodic time intervals, immediately in response to certain events, or in response to a refresh query from the FLISR unit  135 . 
     As shown in block  510 , the FLISR unit  135  identifies an upstream isolation device  305  representing the isolation device  305  immediately upstream of the fault, and as shown in block  515 , the FLISR unit  135  identifies a downstream isolation device  305  representing the isolation device  305  immediately downstream of the fault. In the example of  FIG.  4 B , the R 14  isolation device  305  is the upstream isolation device  305 , and the R 13  isolation device  305  is the downstream isolation device  305 . In general, the isolation devices  305  downstream of the R 5  isolation device  305 , but positioned before or upstream of the fault, should have the same fault state as the R 5  isolation device  305 . The isolation device  305  immediately downstream of the fault should have a fault state that is clear since the fault does not affect the transmission lines associated with that isolation device  305 . In some embodiments, the isolation device  305  that locks out and generates the fault indication is also the upstream isolation device  305 . The FLISR unit  135  identifies the isolation device  305  furthest downstream in a string of isolation devices  305  having a fault state that matches the fault state of the triggering R 5  isolation device  305  as the upstream isolation device (in this example, the R 14  isolation device  305 ) (block  510 ). The FLISR unit  135  identifies the isolation device  305  downstream of the R 14  upstream isolation device  305  having a fault state that does not register the fault seen by the triggering R 5  isolation device as the downstream isolation device  305  (in this example, the R 13  isolation device  305 ). 
     As shown in block  520 , the FLISR unit  135  identifies a fault mismatch. A fault mismatch is registered in response to an isolation device  305  downstream of the triggering R 5  isolation device  305  having a fault state that registers a different fault condition than the fault state of the triggering isolation device  305 . For example, a mismatch may be identified in an example where the triggering isolation device  305  registers a phase to phase fault affecting phases B and C, and one of the downstream isolation devices  305  registers a fault with phase A. Although block  520  is illustrated as being performed after block  515 , the mismatch condition is identified concurrently with the identification of the upstream isolation device  305  (block  510 ) and the identification of the downstream isolation device  305  (block  515 ). In some embodiments, if a fault mismatch is identified (block  520 ), the FLISR unit  135  opens all phases of the isolation device  305  prior to the fault mismatch as shown in block  525  and proceeds with three-phase restoration. If a fault mismatch is not identified (block  520 ), the FLISR unit  135  proceeds with single phase restoration operations. Alternatively, in some embodiments, the fault state of the triggering isolation device  305  controls the fault handling, even if one of the isolation devices  305  downstream of the triggering isolation device  305  has a fault mismatch. 
     As shown in block  530 , the FLISR unit  135  sends open commands for the faulted phases in the first subset to the R 13  downstream isolation device  305 , as illustrated in  FIG.  4 C . In some embodiments, the FLISR unit  135  also sends open commands to the R 14  upstream isolation device  305  prior to opening the R 13  downstream isolation device  305 . In an instance where the isolation device  305  identifying the fault condition is also the upstream isolation device  305  (in this example, closest to the fault), the isolation device  305  identifying the fault condition is already open for the faulted states, and an open command need not be sent to the upstream isolation device  305 . 
     As shown in block  535 , the FLISR unit  135  sends close commands for the faulted phases in the first subset to the R 5  isolation device  305  that triggered the fault condition. In an instance where the isolation device  305  identifying the fault condition is also the upstream isolation device  305  (in this example, closest to the fault), close commands need not be sent to the upstream isolation device  305 . Closing the non-faulted phases restores power to customers up to the R 14  upstream isolation device  305 . In some embodiments, when there are multiple non-faulted phases, the FLISR unit  135  closes the non-faulted phases individually using sequential close commands. 
     As shown in block  540 , the FLISR unit  135  sends close commands for a tie-in isolation device  305 , as illustrated in  FIG.  4 E . For example, the R 12  isolation device  305  is downstream of the fault and the R 13  downstream isolation device  305  and can provide power from the source S 3 . In some embodiments, the FLISR unit  135  sends a ganged close command to the R 12  tie-in isolation device  305 . In some embodiments, the FLISR unit  135  sends mode messages to the R 5 , R 14 , R 13 , R 12 , R 8 , R 10 , R 11  isolation devices  305  on the parallel phases to the alternate source S 3  placing them in one-shot mode prior to sending the close commands. Thus, if one of the isolation devices  305  on the parallel phases trips, automatic reclosing is prevented. 
     As shown in block  545 , the FLISR unit  135  sends open commands to the R 13  downstream isolation device  305  for the parallel phases (in this example, the phases in the second subset), as illustrated in  FIG.  4 F . For example, the A phase for the R 13  isolation device  305  is fed by both the source S 2  and the source S 3 . Opening the non-faulted phase removes this parallel source condition. In some embodiments, when there are multiple non-faulted phases in the second subset, the FLISR unit  135  opens the non-faulted phases on the R 13  downstream isolation device  305  individually using sequential open commands. In some embodiments, after completing the tie-in processing (block  545 ) without any trips, the FLISR unit  135  sends mode messages to the R 15 , R 14 , R 13 , R 12 , R 8 , R 10 , and R 11  isolation devices  305  on the path to both sources S 2 , S 3  placing them back in reclose mode. 
     As shown in block  550 , the FLISR unit  135  sends fault state reset commands to the R 5  and R 14  isolation devices  305  to reset the fault states and allow fault monitoring to be processed using the re-configured the power distribution network  105 . 
     Referring to  FIGS.  6 A- 6 E  and  FIG.  7   , the operation of the system of  FIG.  1    is illustrated for handling a loss of voltage (LOV) fault.  FIGS.  6 A- 6 E  are diagrams illustrating the operation of the system of  FIG.  1    to handle an LOV fault in a portion of the power distribution network  105  of  FIG.  2   , according to some embodiments.  FIG.  7    is a flowchart of a method  700  for operating of the system of  FIG.  1    for an LOV fault, according to some embodiments. 
     In some embodiments, an LOV fault is detected by one or more of the isolation devices  305 , but does not cause an automatic lockout or trip of the identifying isolation device  305 . An LOV fault is defined as an event where the measured voltage on at least one phase drops below a predefined threshold level. In some embodiments, the predefined threshold level (for example, 5-95%) is a user-specified parameter. 
     Referring to  FIG.  7   , an LOV fault indication is received as shown in block  705 , for example, from the R 2  isolation device  305  (in this example, as indicated by the “!” (exclamation mark) in the R 2  block). In some instances, the isolation device  305  that identifies the LOV fault is not the isolation device  305  closest to the fault. For example, the communication links between the isolation devices  305  and the FLISR unit  135  may have different latencies. For purposes of the following example, assume that the LOV fault is present due to a fault between the R 4  isolation device  305  and the R 6  isolation device  305  on the A phase, and the R 2  isolation device  305  identifies the LOV fault responsive to the voltage dropping below the predefined threshold.  FIG.  6 A  illustrates the power distribution network  105  prior to any automatic operations, with the fault illustrated on the A phase between the R 4  and R 6  isolation devices  305 . The FLISR unit  135  identifies a first subset of the phases that includes the faulted phase, A, and a second subset of the phases that includes the non-faulted phases, B and C. 
     As shown in block  710 , the FLISR unit  135  determines if the LOV fault is associated with an immediate lockout condition. In some embodiments, immediate lockout conditions include the LOV fault occurring at a transformer or at a substation, indicating an equipment failure. If an immediate lockout condition is identified (block  710 ), the FLISR unit  135  initiates a lockout of all phases of the isolation devices  305  closest to the LOV fault as shown in block  715 . 
     As shown in block  720 , the FLISR unit  135  determines if the LOV fault is associated with a concurrent underfrequency event. If a concurrent underfrequency event is identified, the FLISR unit  135  ignores the LOV event as shown in block  725 . 
     In some embodiments, the FLISR unit  135  waits for a predetermined time interval (for example, 30 seconds) after receiving the lockout fault indication before proceeding with restoration operations. As shown in block  730 , the FLISR unit  135  determines if the LOV fault is still present after the predetermined time interval. The FLISR unit  135  may evaluate the currently reported fault states or send a refresh command to the isolation devices  305  to evaluate the status of the LOV fault upon expiration of the timer (block  730 ). If the LOV fault clears (block  730 ), the FLISR unit  135  ignores the LOV fault as shown in block  725 . If the LOV fault is still present (block  730 ), the FLISR unit  135  attempts to identify the fault location by examining the fault states of other isolation devices  305  starting from the source S 3  and working toward the LOV fault issuing R 2  isolation device  305 . 
     As shown in block  740 , the FLISR unit  135  identifies a downstream isolation device  305  representing the isolation device  305  immediately downstream of the LOV fault. The FLISR unit  135  starts at the source S 3 , and evaluates the fault states of the R 11 , R 10 , R 8 , R 7 , R 6 , and R 4  isolation devices  305 . Isolation devices  305  with asserted faults states are identified with “!” indicators, and isolation devices  305  with clear fault states are identified with “-” indicators in  FIG.  6 B . In the example of  FIG.  6 B , the R 6  isolation device  305  is the last isolation device  305  with a clear fault state, and the R 4  isolation device  305  is the downstream isolation device  305 , as it is the first with an asserted LOV fault state. In general, the isolation devices  305  downstream of the fault, for example, the R 4 , R 2 , and R 3  isolation devices  305 , should have the same asserted LOV fault states, and the R 6  isolation device  305  immediately upstream of the fault should have a LOV fault state that is clear since the fault does not affect the transmission lines associated with the R 6  isolation device  305 . The FLISR unit  135  identifies the isolation device  305  downstream of the R 6  isolation device  305  with an asserted LOV fault state as the downstream isolation device  305  (in this example, the R 4  isolation device  305 ) (block  740 ). 
     As shown in block  745 , the FLISR unit  135  identifies a fault mismatch. A fault mismatch is registered in response to the R 4  isolation device  305  having a fault state that registers a different LOV fault condition than the fault state of the R 2  triggering isolation device  305 . For example, a mismatch may be identified in an example where the R 4  isolation device  305  registers an LOV affecting phase A, and the R 2  triggering isolation devices  305  registers an LOV fault with a different phase. Although block  745  is illustrated as being performed after block  740 , the mismatch condition is identified concurrently with the identification of the downstream isolation device  305  (block  740 ). In some embodiments, if a fault mismatch is identified (block  745 ), the FLISR unit  135  opens all phases of the isolation device  305  with the fault mismatch as shown in block  750  and proceeds with three-phase restoration. If a fault mismatch is not identified (block  745 ), the FLISR unit  135  proceeds with single phase restoration operations. Alternatively, in some embodiments, the fault state of the triggering isolation device  305  controls the fault handling, even if one of the isolation devices  305  downstream of the triggering isolation device  305  has a fault mismatch. 
     As shown in block  755 , the FLISR unit  135  sends open commands for the phases in the first subset affected by the LOV fault (in this example, the A phase) to the R 4  downstream isolation device  305 , as illustrated in  FIG.  6 C . Open transmission lines  200  are illustrated with dashed lines, where an open diamond is adjacent the isolation device  305  isolating the transmission line  200  from a power source. 
     As shown in block  760 , the FLISR unit  135  sends close commands for a tie-in isolation device  305 , as illustrated in  FIG.  6 D . For example, the R 9  isolation device  305  is downstream of the fault and the R 4  downstream isolation device  305  and can provide an alternate path for power from the source S 3 . In some embodiments, the FLISR unit  135  sends a ganged close command to the R 9  tie-in isolation device  305 . In some embodiments, the FLISR unit  135  sends mode messages to the R 10 , R 8 , R 6 , R 7 , R 11 , R 9 , R 3 , R 2 , and R 4  isolation devices  305  on the paralleled phase placing them in one-shot mode prior to sending the close commands. Thus, if one of the isolation devices  305  on the paralleled phases trips, automatic reclosing is prevented. 
     As shown in block  765 , the FLISR unit  135  sends open commands to the R 4  downstream isolation device  305  for the non-faulted phases, as illustrated in  FIG.  6 E . For example, the non-faulted phases in the second subset (in this example, the B and C phases) for the R 4  isolation device  305  are fed by the source S 3  from both sides. Opening the non-faulted phase(s) removes this looped source condition. In some embodiments, when there are multiple non-faulted phases, the FLISR unit  135  opens the non-faulted phases on the R 4  downstream isolation device  305  individually using sequential open commands. In some embodiments, after completing the tie-in processing (block  765 ) without any trips, the FLISR unit  135  sends mode messages to the R 7 , R 6 , R 4 , R 3 , R 2 , R 8 , R 10 , and R 11  isolation devices  305  placing them back in reclose mode. 
     Referring to  FIGS.  8 A- 8 D  and  FIG.  9   , the operation of the system of  FIG.  1    to perform a fault restoration operation that avoids loop configurations is illustrated.  FIGS.  8 A- 8 D  are diagrams illustrating the operation of the system of  FIG.  1    to avoid loop configurations during fault restoration in a portion of the power distribution network  105  of  FIG.  2   , according to some embodiments.  FIG.  9    is a flowchart of a method  900  for operating of the system of  FIG.  1    to avoid loop configurations during fault restoration, according to some embodiments. For purposes of this illustration, a loop configuration is defined as a configuration where the same source feeds both the faulted line section and the tie-in isolation device  305 . The processing of  FIGS.  8 A- 8 D  and  FIG.  9    may be combined with the methods described above in  FIGS.  5  and  7   . 
     As shown in block  905 , a fault indication is received. In some embodiments, the fault indication is a lockout fault (for example, current fault, phase to phase fault, ground fault, etc.) In some embodiments, the fault indication is an LOV fault. For purposes of discussion, the fault received in block  905  is an LOV fault present between the R 6  and R 4  isolation devices  305 , as shown in  FIG.  8 A . As described above, any of the isolation devices  305  downstream of the fault may register the LOV event, such as the R 4 , R 2 , or R 3  isolation devices. In this example, the R 4  isolation device  305  registers the fault, as indicated by the “!” in the R 6  block. If one of the other isolation devices  305  registered the fault, the FLISR unit  135  evaluates the fault states to identify the isolation device  305  closest to the fault, as described above in reference to  FIG.  7   . 
     As shown in block  910  and  FIG.  8 B , the FLISR unit  135  isolates the fault. In some embodiments, the FLISR unit  135  isolates the fault by opening the subset of the phases associated with the fault on the downstream isolation device, which in the example of  FIGS.  8 A- 8 D , is the “A” phase of the R 4  isolation device  305 . In some embodiments, where the fault is a lockout fault, the isolation device  305  that initiates the fault detection and initially opens is not the isolation device  305  closest to the fault. In such a scenario, the FLISR unit  135  also identifies and opens subset of the phases associated with the fault for the upstream isolation device as described above in reference to  FIG.  5   . 
     As shown in block  915 , the FLISR unit  135  identifies one or more tie-in isolation devices  305  that should be closed to restore power to lines downstream of the fault. In the example of  FIGS.  8 A- 8 D , the tie-in isolation device  305  is the R 9  isolation device  305 . 
     In block  920 , the FLISR unit  135  determines if a potential loop configuration is associated with the closing of the tie-in isolation device  305 . In some embodiments, the FLISR unit  135  identifies a potential loop configuration responsive to the tie-in isolation device  305  being supplied by the same source as the faulted isolation device  305 . In this example, the R 4  isolation device  305  associated with the faulted phase is supplied by the source S 3 , and the alternate source for the R 9  tie-in isolation device  305  is also supplied by the source S 3 , so the potential loop configuration is present in block  920 . 
     Responsive to a potential loop configuration not being present in block  920 , the FLISR unit  135  follows the process described above in reference to  FIGS.  5  and  7    by sending a close command to the tie-in isolation device  305  as shown in block  925  and sending an open command to the downstream isolation device  305  for the non-faulted phases in block  930 . 
     In this example, a potential loop configuration is associated with the closing of the R 9  tie-in isolation device  305 . Responsive to a potential loop configuration being present in block  920 , the FLISR unit  135  sends an open command to the R 4  downstream isolation device  305  for the non-affected phases (in this example, the phases in the second subset) in block  935 , as illustrated in  FIG.  8 C . 
     As shown in block  940 , the FLISR unit  135  sends a close command to the R 9  tie-in isolation device  305 , as illustrated in  FIG.  8 D . In some embodiments, the FLISR unit  135  sends a ganged close command to the R 9  tie-in isolation device  305 . Opening the non-affected phases of the R 4  isolation device  305  in block  935  prior to closing the R 9  tie-in isolation device  305  avoids the loop configuration. 
     Referring to  FIGS.  10 A- 10 G  and  FIG.  11   , the operation of the system of  FIG.  1    to perform a fault restoration operation that avoids loop configurations associated with multiple tie-in isolation devices  301  is illustrated.  FIGS.  10 A- 10 G  are diagrams illustrating the operation of the system of  FIG.  1    to avoid loop configurations with multiple tie-in isolation devices  305  during fault restoration in a portion of the power distribution network  105  of  FIG.  2   , according to some embodiments.  FIG.  11    is a flowchart of a method  1100  for operating of the system of  FIG.  1    to avoid loop configurations during fault restoration with multiple tie-in isolation devices  305 , according to some embodiments. For purposes of this illustration, a loop configuration is defined as a configuration where the multiple tie-in isolation devices  305  are fed by the same source. The processing of  FIGS.  10 A- 10 G  and  FIG.  11    may be combined with the methods described above in  FIGS.  5  and  7   . 
     As shown in block  1105 , a fault indication is received. In some embodiments, the fault indication is a lockout fault (for example, current fault, phase to phase fault, ground fault, etc.) In some embodiments, the fault indication is an LOV fault. For purposes of discussion, the fault received in block  1105  is a lockout fault on the “A” phase present between the R 1 , R 4 , and R 2  isolation devices  305 , as shown in  FIG.  10 A . The lockout fault is identified by the R 1  isolation device  305  (in this example, as indicated by the “!” in the R 1  block). In the example of  FIG.  10 A , the R 1  isolation device  305  is both the isolation device that identifies and locks out the fault condition and the isolation device  305  closest to the fault (in this example, the upstream isolation device  305  in the context of  FIG.  5   ). If a different isolation device  305  upstream of the R 1  isolation device registers the fault, the FLISR unit  135  evaluates the fault states to identify the upstream isolation device  305  closest to the fault, as described above in reference to  FIG.  5   . 
     As shown in block  1110  and  FIG.  10 B , the FLISR unit  135  isolates the fault. In some embodiments, the FLISR unit  135  isolates the fault by opening the subset of the phases associated with the fault on the downstream isolation device, which in the example of  FIGS.  10 A- 10 G , is the “A” phase of the R 4  and R 2  isolation devices  305 . 
     As shown in block  1115 , the FLISR unit  135  identifies one or more tie-in isolation devices  305  that should be closed to restore power to lines downstream of the fault. In the example of  FIGS.  10 A- 10 G , the tie-in isolation devices  305  include the R 7  and R 9  isolation devices  305 . The R 7  tie-in isolation device  305  is associated with the R 4  downstream isolation device  305 , and the R 9  tie-in isolation device  305  is associated with the R 2  downstream isolation device  305 . 
     In block  1120 , the FLISR unit  135  determines if a potential loop configuration is associated with the closing of multiple tie-in isolation devices  305 . In some embodiments, the FLISR unit  135  identifies a potential loop configuration responsive to multiple tie-in isolation devices  305  being supplied by the same source. In this example, the R 7  and R 9  tie-in isolation devices  305  are supplied by the source S 3 , so the loop configuration is present in block  1120 . 
     If a potential loop configuration is not present in block  1120  (for example, multiple tie-in isolation devices  305  supplied by different sources), the FLISR unit  135  follows the process described above in reference to  FIGS.  5  and  7    by closing the multiple tie-in isolation devices  305  as shown in block  1125  and sending an open command to the downstream isolation device  305  for the non-faulted phases in block  1130 . 
     In this example, a potential loop configuration is associated with the R 7  and R 9  tie-in isolation devices  305 . Closing the R 7  and R 9  tie-in isolation devices  305  would create a loop because the source S 3  is common to both the R 7  and R 9  tie-in isolation devices  305 . Responsive to a multiple tie-in potential loop configuration being present in block  1120 , the FLISR unit  135  processes the tie-in isolation devices  305  individually, as shown in block  1135 . 
     As shown in block  1140 , the FLISR unit  135  sends a close command to the tie-in isolation device  305  and send an open command to the downstream isolation device  305  associated with the tie-in isolation device  305  for the non-faulted phases. When processing each tie-in isolation device  305 , the FLISR unit  135  also evaluates the loop configuration as described in the method  900  of  FIG.  9    for a single tie-in isolation device  305 . Hence, the order of the close command and the open command may vary, as shown in  FIG.  9   . 
     Since the R 7  tie-in isolation device  305  does not have the same source (for example, source S 3 ) that was feeding the faulted line section (for example, source S 1 ), the FLISR unit  135  sends a close command to the R 7  tie-in isolation device  305  (block  925  of  FIG.  9   ), as illustrated in  FIG.  10 D  followed by an open command to the R 4  downstream isolation device  305  associated with the R 7  tie-in isolation device for the non-faulted phases (block  930  of  FIG.  9   ), as illustrated in  FIG.  10 E . In some embodiments, the FLISR unit  135  sends a ganged close command to the R 7  tie-in isolation device  305 . 
     As shown in block  1145 , the FLISR unit  135  determines if another tie-in isolation device  305  remains to be processed. In this example, the R 9  isolation device  305  is still pending. Responsive to an unprocessed tie-in isolation device  305  remaining in block  1145 , the FLISR unit  135  returns to block  1140 . 
     Since the R 9  tie-in isolation device  305  does not have the same source (for example, source S 3 ) that was feeding the faulted line section (for example, source S 1 ), the FLISR unit  135  sends a close command to the R 9  tie-in isolation device  305  (block  925  of  FIG.  9   ), as illustrated in  FIG.  10 F  followed by an open command to the R 2  downstream isolation device  305  associated with the R 9  tie-in isolation device  305  for the non-faulted phases (block  930  of  FIG.  9   ), as illustrated in  FIG.  10 G . In some embodiments, the FLISR unit  135  sends a ganged close command to the R 9  tie-in isolation device  305 . 
     If no unprocessed tie-in isolation devices  305  are present in block  1145 , the method  1100  terminates at clock  1150 . Processing the multiple tie-in isolation devices  305  with a common source individually avoids loop configurations. 
       FIGS.  12 A- 12 G  are diagrams illustrating the operation of the system of  FIG.  1    to avoid loop configurations according to the method  1100  of  FIG.  11   , according to some embodiments. The fault condition is similar to that illustrated in  FIG.  10 A . At the point illustrated in  FIG.  12 A , the FLISR unit  135  has isolated the fault by opening the subset of the phases associated with the fault on the downstream isolation devices, which in the example of  FIGS.  12 A- 12 G , is the “A” phase of the R 15 , R 4 , and R 2  isolation devices  305 . The R 7  tie-in isolation device  305  is associated with the R 4  downstream isolation device  305 , the R 9  tie-in isolation device  305  is associated with the R 2  downstream isolation device  305 , and the R 16  tie-in isolation device  305  is associated with the R 15  downstream isolation device  305 . 
     In the example illustrated in  FIG.  12 A , three tie-in isolation devices  305  are present, the R 16 , R 7 , and R 9  tie-in isolation devices  305 . Since the R 7  and R 9  tie-in isolation devices  305  share a common source S 3 , the tie-in isolation devices  305  are processed individually according to the multiple tie-in loop configuration identified in block  1120  of  FIG.  11   . 
     In the illustrated example, the FLISR unit  135  starts with the R 9  isolation device  305  at block  1140 . Since the R 9  tie-in isolation device  305  does not have the same source (for example, source S 3 ) that was feeding the faulted line section (for example, source S 1 ), the FLISR unit  135  sends a close command to the R 9  tie-in isolation device  305  (block  925  of  FIG.  9   ), as illustrated in  FIG.  12 B  followed by an open command to the R 2  downstream isolation device  305  for the non-faulted phases (block  930  of  FIG.  9   ), as illustrated in  FIG.  12 C . In some embodiments, the FLISR unit  135  sends a ganged close command to the R 9  tie-in isolation device  305 . 
     As shown in block  1145 , the FLISR unit  135  determines if another tie-in isolation device  305  to be processed. In this example, the R 16  and R 7  isolation devices  305  are still pending. Responsive to an unprocessed tie-in isolation device  305  remaining in block  1145 , the FLISR unit  135  returns to block  1140  to process the R 16  tie-in isolation device  305 . 
     In this example, the R 16  tie-in isolation device  305  does have the same alternate source (for example, source S 1 ) that was feeding the faulted line section (for example, source S 1 ), so a loop configuration is present in block  920  of  FIG.  9   . The FLISR unit  135  sends an open command to the R 15  downstream isolation device  305  for the non-faulted phases (block  935  of  FIG.  9   ), as illustrated in  FIG.  12 D  followed by a close command to the R 16  tie-in isolation device  305  (block  940  of  FIG.  9   ), as illustrated in  FIG.  12 E . In some embodiments, the FLISR unit  135  sends a ganged close command to the R 16  tie-in isolation device  305 . 
     As shown in block  1145 , the FLISR unit  135  determines if another tie-in isolation device  305  remains to be processed. In this example, the R 7  isolation device  305  is still pending. Responsive to an unprocessed tie-in isolation device  305  remaining in block  1145 , the FLISR unit  135  returns to block  1140  to process the R 7  tie-in isolation device  305 . 
     Since the R 7  tie-in isolation device  305  does not have the same source (for example, source S 3 ) that was feeding the faulted line section (for example, source S 1 ), the FLISR unit  135  sends a close command to the R 7  tie-in isolation device  305  (block  925  of  FIG.  9   ), as illustrated in  FIG.  12 F  followed by an open command to the R 15  downstream isolation device  305  for the non-faulted phases (block  930  of  FIG.  9   ), as illustrated in  FIG.  12 G . In some embodiments, the FLISR unit  135  sends a ganged close command to the R 7  tie-in isolation device  305 . 
     Among other things, the techniques described herein isolate faults and restore power using an individual phase approach. This approach increases system utilization by reducing the number of customers experiencing power outages as a result from a fault condition, thereby increasing customer satisfaction and preserving revenue generated by the non-affected phases. 
     In some embodiments, the FLISR unit implements fault processing while performing the method  900  of  FIG.  9    or the method  1100  of  FIG.  11   . Consider the example illustrated in  12 B where the FLISR unit sent a close command to the R 9  tie-in isolation device  305  (block  925  of  FIG.  9   ) followed by an open command to the R 2  downstream isolation device  305  for the non-faulted phases (block  930  of  FIG.  9   ). In this example, the R 2  isolation device  305  fails to respond to the open command. This failure to respond may be the result of a communication error or equipment failure. The FLISR unit  135  identifies a FLISR processing exception when it fails to receive a confirmation that the R 2  isolation device  305  implemented the open command within a predetermined time period. As seen in  FIG.  12 B , a parallel source condition exists where the source S 1  and the source S 3  are both supplying the non-faulted phases associated with the R 2  downstream isolation device  305 . In response to the FLISR unit  135  identifying the FLISR processing exception and determining that at the faulted step, a parallel source condition exists, the FLISR unit  135  opens the R 9  tie-in isolation device to remove the parallel source condition. The FLISR unit  135  generates a failure report including a FLISR processing exception indicator, the action taken, and the steps remaining after the FLISR fault that were not completed. In this example, the remaining steps include the commands to process the R 16  and R 7  tie-in isolation devices  305 . 
     Consider another example illustrated in  12 D where the FLISR unit sent an open command to the R 15  downstream isolation device  305  for the non-faulted phases (block  935  of  FIG.  9   ), followed by a close command to the R 16  tie-in isolation device  305  (block  940  of  FIG.  9   ). In this example, the R 16  tie-in isolation device  305  fails to respond to the close command. This failure to respond may be the result of a communication error or equipment failure. The FLISR unit  135  identifies a FLISR processing exception when it fails to receive a confirmation that the R 16  tie-in isolation device  305  implemented the close command within a predetermined time period. As seen in  FIG.  12 D , because the order of the close command to the R 16  tie-in isolation device  305  and the open command to the R 15  downstream isolation device  305  was reversed to avoid a loop configuration, a parallel source condition does not exist. The source S 1  does not supply the non-faulted phases associated with the R 15  downstream isolation device  305 . 
     In response to the FLISR unit  135  identifying the FLISR processing exception and determining that at the faulted step, a parallel source condition does not exist, the FLISR unit  135  need not take any additional action. The FLISR unit  135  generates a failure report including a FLISR processing exception indicator and the steps remaining after the FLISR fault that were not completed. In this example, the remaining steps include the commands to process the R 7  tie-in isolation device  305 . 
     The following examples illustrate example systems and methods described herein. 
     Example 1: a system for controlling a power distribution network providing power using a plurality of phases, the system comprising: an electronic processor configured to: receive a first fault indication associated with a fault in the power distribution network from a first isolation device of a plurality of isolation devices; identify a first subset of the plurality of phases associated with the first fault indication and a second subset of the plurality of phases not associated with the first fault indication, wherein the first subset and the second subset each include at least one member; identify a set of downstream isolation devices downstream of the fault; send a first open command to each member of the set of downstream isolation devices for each phase in the first subset; identify a plurality of tie-in isolation devices to be closed to restore power, each of the tie-in isolation devices being associated with one of the set of downstream isolation devices; and responsive to identifying a first potential loop configuration, for each of the plurality of tie-in devices: send a close command to the tie-in isolation device for each of the plurality of phases; and send a second open command to the associated downstream isolation device for each phase in the second subset, wherein the sending of the close command and the second open command are completed for each of the plurality of tie-in isolation devices prior to processing remaining ones of the plurality of tie-in isolation devices. 
     Example 2: the system of example 1, wherein the electronic processor is configured to: identify the potential loop configuration responsive to at least two of the plurality of tie-in isolation devices being supplied by a common power source. 
     Example 3: the system of examples 1-3, wherein the electronic processor is configured to: responsive to identifying a second potential loop configuration associated with a selected one of the plurality of tie-in isolation devices, sending the second open command prior to sending the close command. 
     Example 4: the system of examples 1-3, wherein the electronic processor is configured to: identify the second potential loop configuration responsive to a first source supplying the selected one of the plurality of tie-in isolation devices and the downstream isolation device associated with the selected one of the plurality of tie-in isolation devices. 
     Example 5: the system of examples 1-4, wherein the electronic processor is configured to: identify a processing exception responsive to the downstream isolation device associated with a selected one of the plurality of tie-in isolation devices failing to execute the second open command after the selected tie-in isolation device executes the close command; and send a third open command to the selected one of the plurality of tie-in isolation devices for each of the plurality of phases responsive to identifying the processing exception. 
     Example 6: the system of examples 1-5, wherein the electronic processor is configured to: identify a processing exception associated with the sending of the first open command, the close command, or the second open command; and generate an exception report indicating the processing exception and uncompleted steps associated with the processing of the first fault indication. 
     Example 7: the system of examples 1-6, wherein the electronic processor is configured to: identify an upstream isolation device upstream of the fault; and responsive to the first isolation device not being the upstream isolation device, send a close command to the first isolation device for each phase in the first subset. 
     Example 8: the system of examples 1-7, wherein the electronic processor is configured to: send the close command to the tie-in isolation device by sending a ganged close command to concurrently close all of the phases of the tie-in isolation device. 
     Example 9: the system of examples 1-8, wherein the fault comprises a lockout fault that results in the first isolation device opening a first subset of the plurality of phases. 
     Example 10: the system of examples 1-9, wherein the fault comprises a loss of voltage fault. 
     Example 11: a method for controlling a power distribution network providing power using a plurality of phases, comprising: receiving, via an electronic processor, a first fault indication associated with a fault in the power distribution network from a first isolation device of a plurality of isolation devices; identifying, via the electronic processor, a first subset of the plurality of phases associated with the first fault indication and a second subset of the plurality of phases not associated with the first fault indication, wherein the first subset and the second subset each include at least one member; identifying, via the electronic, a set of downstream isolation devices downstream of the fault; sending, via the electronic processor, a first open command to each member of the set of downstream isolation devices for each phase in the first subset; identifying, via the electronic processor, a set of downstream isolation devices downstream of the fault; sending, via the electronic processor, a first open command to each member of the set of downstream isolation devices for each phase in the first subset; identifying, via the electronic processor, a plurality of tie-in isolation devices to be closed to restore power, each of the tie-in isolation devices being associated with one of the set of downstream isolation devices; and responsive to identifying, via the electronic processor, a first potential loop configuration, for each of the plurality of tie-in devices: sending, via the electronic processor, a close command to the tie-in isolation device for each of the plurality of phases; and sending, via the electronic processor, a second open command to the associated downstream isolation device for each phase in the second subset, wherein the sending of the close command and the second open command are completed for each of the plurality of tie-in isolation devices prior to processing remaining ones of the plurality of tie-in isolation devices. 
     Example 12: the method of example 11, comprising: identifying, via the electronic processor, the potential loop configuration responsive to at least two of the plurality of tie-in isolation devices being supplied by a common power source. 
     Example 13: the method of examples 11-12, comprising: responsive to identifying, via the electronic processor, a second potential loop configuration associated with a selected one of the plurality of tie-in isolation devices, sending the second open command prior to sending the close command. 
     Example 14: the method of examples 11-13, comprising: identifying, via the electronic processor, the second potential loop configuration responsive to a first source supplying the selected one of the plurality of tie-in isolation devices and the downstream isolation device associated with the selected one of the plurality of tie-in isolation devices. 
     Example 15: the method of examples 11-14, comprising: identifying, via the electronic processor, a processing exception responsive to the downstream isolation device associated with a selected one of the plurality of tie-in isolation devices failing to execute the second open command after the selected tie-in isolation device executes the close command; and sending, via the electronic processor, a third open command to the selected one of the plurality of tie-in isolation devices for each of the plurality of phases responsive to identifying the processing exception. 
     Example 16: the method of examples 11-15, comprising: identifying, via the electronic processor, a processing exception associated with the sending of the first open command, the close command, or the second open command; and generating, via the electronic processor, an exception report indicating the processing exception and uncompleted steps associated with the processing of the first fault indication. 
     Example 17: the method of examples 11-16, comprising: identifying, via the electronic processor, an upstream isolation device upstream of the fault; and responsive to the first isolation device not being the upstream isolation device, sending, via the electronic processor, a close command to the first isolation device for each phase in the first subset. 
     Example 18: the method of examples 11-17, comprising: sending, via the electronic processor, the close command to the tie-in isolation device by sending a ganged close command to concurrently close all of the phases of the tie-in isolation device. 
     Example 19: the method of examples 11-18, wherein the fault comprises a lockout fault that results in the first isolation device opening the first subset of the plurality of phases. 
     Example 20: the method of examples 11-19, wherein the fault comprises a loss of voltage fault. 
     Various features and advantages of the embodiments described herein are set forth in the following claims.