A distributed feeder automation fault handling method and system

Abstract

A kind of distributed feeder automation fault processing method and system, including: distribution line station terminal obtains the current of the position of circuit breaker connected therewith, the voltage at bus side and circuit breaker state, and the state of circuit breaker connected by other distribution line station terminal;Distribution line station terminal is based on the current of the position of circuit breaker connected therewith, voltage at bus side and circuit breaker state, in combination with the state of circuit breaker connected by adjacent distribution line station terminal, determines fault point;Distribution line station terminal handles the fault point.The present application detects the characteristic difference of fault section by distribution line station terminal itself, communicates between terminal, and automatically realizes the function of fault location, isolation and non-fault area power supply recovery of feeder.

Description

Technical Field

[0001] This invention relates to the field of fault handling, and specifically to an automated fault handling method and system for distributed feeders. Background Technology

[0002] The distribution automation system has functions such as distribution SCADA (supervisory control and data acquisition), fault handling, analysis and application, and interconnection with related application systems. It mainly consists of a distribution automation system master station, distribution automation system substations (optional), distribution automation terminals, and communication networks. It realizes the monitoring and control of distribution network operation by utilizing modern computer and communication technologies.

[0003] Feeder automation, as a core component of distribution automation systems, plays a crucial role in rapidly isolating faults, restoring power to non-faulty areas, and improving power supply reliability. Feeder automation can be implemented in three main ways: local, centralized, and distributed. Local feeder automation is primarily used for overhead lines in suburban or rural areas where power quality requirements are not high and communication is lacking. Centralized feeder automation (centralized FA), relying on sophisticated communication methods and master station decision-making, is costly, and its operation and power restoration time often exceeds minutes. Distributed feeder automation (distributed FA), through peer-to-peer communication between distribution terminals, does not rely on master station (substation) decision-making, enabling millisecond-level fault location, second-level rapid isolation, and power restoration to non-faulty areas within seconds. Therefore, distributed FA, due to its high efficiency and intelligence, is suitable for Class A+ and Class A cable lines in urban areas with high power supply reliability requirements, as well as distribution network structures such as ring networks, multi-source interconnections, and petal-shaped systems operating in open or closed loops.

[0004] Distributed FA does not rely on master station or substation for decision-making. It mainly detects the differences in characteristics such as short-circuit current and grounding fault on both sides of the fault section through the terminal itself. The terminals establish a peer-to-peer communication network and communicate with each other to assist in decision-making. Finally, it automatically realizes the functions of fault location and isolation of feeders and restoration of power supply to non-faulty areas, and reports the processing process and results to the distribution automation master station.

[0005] However, the current fault detection strategy for distribution line substation terminals using distributed FA is not perfect enough and cannot accurately locate faults. Summary of the Invention

[0006] To overcome the shortcomings of existing distributed feeder automation (FA) fault detection strategies for distribution line substation terminals, which are insufficient for accurate fault location, this invention provides a distributed feeder automation fault handling method, comprising:

[0007] The distribution line station terminal obtains the current at the location of the circuit breaker connected to it, the voltage on the bus side, and the status of the circuit breaker, as well as the status of the circuit breakers connected to other distribution line station terminals.

[0008] The fault point is determined by the current, bus voltage and circuit breaker status of the circuit breaker at the location of the circuit breaker connected to it, combined with the status of the circuit breakers connected to the adjacent distribution line substations.

[0009] The power distribution line station terminal handles the fault point.

[0010] Preferably, the distribution line substation terminal acquires the current, bus voltage, and circuit breaker status at the location of the circuit breaker it is connected to, including:

[0011] The distribution line station terminal senses the current of the circuit breaker based on the current transformer installed at the location of the circuit breaker, and senses the voltage of the bus on this side based on the voltage transformer installed at the bus.

[0012] The power distribution line station terminal obtains the switching status of the circuit breaker directly connected to the power distribution line station terminal using either hard remote signaling or soft remote signaling.

[0013] Preferably, the fault point is determined by the distribution line substation terminal based on the current at the location of the circuit breaker connected to it, the bus voltage, and the circuit breaker status, combined with the status of the circuit breakers connected to adjacent distribution line substation terminals, including:

[0014] The power distribution line station terminal performs phase overcurrent and zero-sequence overcurrent judgment on the current, and determines whether there is phase overcurrent and zero-sequence overcurrent in the circuit breaker directly connected to the power distribution line station terminal;

[0015] The distribution line station terminal performs voltage identification on the bus side to determine whether the bus where the distribution line station terminal is located is energized;

[0016] The fault point is determined by the distribution line station terminal based on its own phase overcurrent, zero-sequence overcurrent and whether the bus is energized, combined with the status of the circuit breaker connected to the adjacent distribution line station terminal.

[0017] Preferably, the power distribution line substation terminal processes the fault point, including:

[0018] When the fault point is the first circuit breaker, the first switch undervoltage protection mode is activated to handle the fault point, and the first switch is closed after the fault is cleared.

[0019] When the fault point is a circuit breaker on the main line, the circuit breakers upstream and downstream of the fault point are tripped with a time delay to isolate the fault point. After the fault is cleared, a closing signal is sent to the circuit breakers upstream and downstream of the fault point to restore power supply to the fault point.

[0020] Preferred options also include:

[0021] When the fault point is isolated by delay tripping of the upstream and downstream circuit breakers, the circuit breaker is judged to be refusing to operate if any of the judgment conditions are met.

[0022] Preferably, the judgment conditions include:

[0023] There is current after the circuit breaker upstream of the fault point triggers isolation action;

[0024] After the circuit breaker downstream of the fault point triggers the isolation action, the circuit breaker remains closed and current is present.

[0025] After the first switch triggers the undervoltage protection action, the first switch remains in the closed state and current is present.

[0026] Preferred options also include,

[0027] When the first circuit breaker upstream of the fault point fails to operate, the failure protection of the second circuit breaker upstream of the fault point is triggered, and the isolation logic is initiated.

[0028] When the first circuit breaker downstream of the fault point fails to operate, the failure protection of the second circuit breaker downstream of the fault point is triggered, and the isolation logic is initiated.

[0029] When the first switch fails to operate, the first switch is put into failure protection and the isolation logic is activated.

[0030] Based on the same inventive concept, the present invention also provides a distributed feeder automated fault handling system, comprising: interconnected power distribution line station terminals and circuit breakers;

[0031] The distribution line substation terminal is used to acquire the current, bus voltage, and circuit breaker status at the location of the circuit breaker connected to it, as well as the status of circuit breakers connected to other distribution line substation terminals; and to determine the fault point based on the current, bus voltage, and circuit breaker status at the location of the circuit breaker connected to it, combined with the status of circuit breakers connected to adjacent distribution line substation terminals; and to process the fault point.

[0032] The circuit breaker is installed on the power distribution line, and the user receives instructions from the terminal of the power distribution line station to perform opening and closing actions.

[0033] Preferably, the substation terminal includes: a data acquisition module, a fault judgment module, and a fault processing module;

[0034] The data acquisition module is used to acquire the current, bus voltage and circuit breaker status at the location of the circuit breaker connected to the terminal of the substation, and transmit the current, bus voltage and circuit breaker status at the location of the circuit breaker to the fault judgment module.

[0035] The fault judgment module is used to judge the phase overcurrent and zero-sequence overcurrent of the current, and to determine whether the circuit breaker directly connected to the terminal of the distribution line station has phase overcurrent and zero-sequence overcurrent; to perform voltage identification on the bus side voltage, and to determine whether the bus where the terminal of the distribution line station is located is energized; based on its own phase overcurrent, zero-sequence overcurrent and the determination of whether the bus is energized, combined with the status of the circuit breaker connected to the terminal of the adjacent distribution line station, to determine the fault point, and to transmit the location of the fault point to the fault processing module;

[0036] The fault handling module is used to handle the fault point by means of isolation or first switch undervoltage protection based on the location of the fault point, and restore the power supply to the fault point after the fault is cleared.

[0037] Preferably, it also includes current transformers and voltage transformers;

[0038] The current transformer is installed at the location of the circuit breaker to sense the current of the circuit breaker and transmit the current to the terminal of the substation.

[0039] The voltage transformer is installed at the busbar to sense the busbar voltage on its side and transmit the busbar voltage to the substation terminal.

[0040] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0041] This invention provides a distributed feeder automated fault handling method, comprising: a distribution line substation terminal acquiring the current, bus voltage, and circuit breaker status at the location of a circuit breaker connected to it, as well as the status of circuit breakers connected to other distribution line substation terminals; the distribution line substation terminal determining the fault point based on the current, bus voltage, and circuit breaker status at the location of the circuit breaker connected to it, combined with the status of circuit breakers connected to adjacent distribution line substation terminals; and the distribution line substation terminal processing the fault point. This invention primarily utilizes the distribution line substation terminal itself to detect differences in short-circuit current and grounding fault characteristics on both sides of the fault section, establishes a peer-to-peer communication network between terminals, and communicates with each other to assist in decision-making, ultimately automatically realizing the functions of fault location, isolation, and power restoration to non-faulty areas of the feeder. Attached Figure Description

[0042] Figure 1 This is a flowchart of a distributed feeder automated fault handling method according to the present invention;

[0043] Figure 2 This is a schematic diagram of the single-ring daisy-chain power distribution network frame of the present invention;

[0044] Figure 3 This is a schematic diagram of the isolation function logic of the present invention;

[0045] Figure 4 This is a schematic diagram of the first switch undervoltage protection function logic of the present invention;

[0046] Figure 5 This is a schematic diagram of the recovery function logic of the present invention;

[0047] Figure 6 This is a schematic diagram of the switch refusal judgment function logic of the present invention;

[0048] Figure 7 This is a schematic diagram of the failure protection function logic of the present invention;

[0049] Figure 8 This is a schematic diagram of the locking function logic of the present invention;

[0050] Figure 9 This is a schematic diagram of the isolation success determination logic of the present invention;

[0051] Figure 10 This is a schematic diagram of the network topology of the present invention;

[0052] Figure 11 This is a schematic diagram of the main line fault case structure of the present invention;

[0053] Figure 12 This is a schematic diagram of the upstream fault case of the first switch in this invention. Detailed Implementation

[0054] As people have increasingly higher requirements for power supply reliability, it is expected that distributed power supply (FA) technology will be widely used in distribution network protection construction in the future.

[0055] To ensure the reliable operation of distributed feeder automation and achieve rapid isolation of distribution network faults and restoration of power supply to non-faulty areas, this invention designs specific action logic for the key functions of high-speed distributed feeder automation. This provides strong foundational support for improving the practical application of distribution automation and promoting the application of key technologies in distributed feeder automation.

[0056] Under normal conditions, after the line fault is located, the upstream and downstream circuit breakers of the faulty section isolate the corresponding faulty section before the feeder protection of the substation outlet circuit breaker operates, thus achieving fault isolation. Subsequently, the tie switch determines whether the tie power supply conditions are met. If they are met, the tie switch closes to restore power to the non-faulty outage area. When a line fault occurs on the substation outgoing side, the fault will be cleared by the feeder protection of the substation's first switch. Simultaneously, if the upstream and downstream circuit breakers of the faulty line fail to operate, their adjacent circuit breakers should operate promptly to clear the fault, minimizing the outage area.

[0057] Based on the above operating conditions, a complete and reliable high-speed distributed feeder automation technology needs to be equipped with: terminal sensing and control technology for line conditions (such as faults, power outages, etc.); and terminal high-speed distributed feeder automation action logic (mainly including seven main functional logics: isolation, first switch undervoltage protection, recovery, switch failure judgment, malfunction protection, interlocking, and isolation success judgment). Therefore, this invention designs a distributed feeder automation fault handling method, and designs specific identification methods and action logic for the above functions to ensure reliable isolation of faulty areas in the distribution network and rapid restoration of power supply to non-faulty areas.

[0058] This invention provides an automated fault handling method for distributed feeders, such as... Figure 1 As shown, it includes:

[0059] Step 1: The distribution line station terminal obtains the current, bus voltage, and circuit breaker status of the circuit breaker at the location of the circuit breaker it is connected to, as well as the status of circuit breakers connected to other distribution line station terminals.

[0060] Step 2: Based on the current, bus voltage, and circuit breaker status at the location of the circuit breaker connected to it, and in conjunction with the status of the circuit breakers connected to adjacent distribution line substations, the fault point is determined.

[0061] Step 3: The power distribution line station terminal processes the fault point.

[0062] The present invention will now be described in detail: In this embodiment, the power distribution line station terminal is referred to as the terminal, and the circuit breaker is also called a switch.

[0063] In step 1, the distribution line substation terminal obtains the current, bus voltage, and circuit breaker status at the location of the circuit breaker it is connected to, as well as the status of circuit breakers connected to other distribution line substation terminals. Specifically, this includes:

[0064] 1. Terminal's perception and control of line conditions:

[0065] Figure 2It is a single-loop, interconnected power distribution network. Circuit breakers 1 / 2 / 3 / 5 / 6 / 7 / 9 / 10 / 11 are each equipped with corresponding distribution line substation terminals for line measurement and control, realizing high-speed distributed feeder automation. Furthermore, an interconnected peer-to-peer communication network (network latency ≤20ms) has been established between all terminals.

[0066] The terminal's perception and control of line conditions includes three main functions: basic remote sensing, remote control, remote monitoring, remote sensing, remote control, remote sensing, and remote information exchange.

[0067] 1.1 The terminal on the line must first be able to perceive the state of the node it is in, which is the foundation of all functions and action logic.

[0068] a) Telemetry: AC analog quantities at the node where the terminal is located, including three-phase currents Ia, Ib, Ic, zero-sequence current I0, three-phase voltages Ua, Ub, Uc, and zero-sequence voltage U0. Figure 2 For example, the station terminal corresponding to circuit breaker 5 can sense Ia, Ib, Ic, and I0 through the current transformer installed at the location of circuit breaker 5, and sense Ua, Ub, Uc, and U0 of the busbar on this side through the voltage transformer installed at the busbar (thick red horizontal line).

[0069] b) Remote signaling: A signal state represented by 0 or 1, used to inform the master station / other terminals of some status information of this terminal. It is mainly divided into two types: hard remote signaling and soft remote signaling. Hard remote signaling refers to the perception of the status of a certain external switch, such as the perception of the open / closed status of circuit breaker 5 by the terminal connected to circuit breaker 5. Soft remote signaling refers to a signal state generated through various logic and judgment, which will be specifically shown below.

[0070] c) Remote control: Used for terminal control of switch opening and closing, in conjunction with the action logic described below.

[0071] In step 2, the fault point is determined based on the current at the location of the circuit breaker connected to it, the bus voltage, and the circuit breaker status, combined with the status of the circuit breakers connected to adjacent distribution line substations. Specifically, this includes:

[0072] 1.2 Internal advanced judgment:

[0073] a) Phase overcurrent detection (mainly used for short-circuit fault detection): It mainly has two parameters: overcurrent setting and overcurrent time, which are used to activate the distributed feeder automatic isolation logic. For example, if the overcurrent setting is configured to 5A and the overcurrent time is 1S, then if the current of any one of Ia, Ib, and Ic exceeds 5A and lasts for more than 1S, it is determined that this switch has detected phase overcurrent.

[0074] b) Zero-sequence overcurrent detection (mainly used for ground fault detection): This mainly involves two parameters: zero-sequence overcurrent setting and zero-sequence overcurrent time. It is used to activate the distributed feeder automated isolation logic. The basic principle is in-phase overcurrent detection; it determines that the switch has detected a zero-sequence overcurrent.

[0075] c) Voltage detection (used to determine whether the bus where this terminal is located is energized): depends on two parameters: voltage setting value and no voltage setting value.

[0076] 1.3 External Information Exchange:

[0077] Because a peer-to-peer communication network has been established between the terminals, they can telemetry, remote signaling, and various information exchange with each other to help each terminal make its own judgment.

[0078] Step 3, where the power distribution line substation terminal processes the fault point, specifically includes:

[0079] 2. Terminal-based high-speed distributed feeder automation logic:

[0080] The automatic operation logic of a high-speed distributed feeder mainly includes the following:

[0081] 2.1 Isolation function:

[0082] The isolation function is used to trip upstream and downstream switches at the fault point, achieving fault area isolation. The terminal determines the faulty section by sensing the status of its own node and upstream and downstream nodes, and then trips the upstream and downstream switches at the fault point after a delay, thus isolating the faulty section. The action logic is as follows: Figure 3 As shown: When the distributed feeder automation isolation function is activated and communication is normal, the action will be activated after a delay once the operating conditions are met. This mainly includes two trips: one upstream and one downstream of the fault point.

[0083] For any terminal, the isolation function generates two associated soft remote signaling signals:

[0084] a) Distributed feeder automated isolation action: This indicates that the isolation function of this terminal has determined to start the action and transmits a trip signal to the switch.

[0085] b) Distributed feeder automation isolation successful: This means that the switch connected to this terminal has been opened and the terminal has sensed the opening status through remote signaling.

[0086] 2.3 First switch undervoltage protection function:

[0087] If the fault occurs upstream of the main switch, such as between circuit breaker A and circuit breaker 1, or between circuit breaker B and circuit breaker 10, the fault area isolation needs to be achieved using the undervoltage protection function of the main switch. The functional logic is as follows: Figure 4 As shown, the action is delayed after the first switch loses voltage once the action conditions are met. It mainly includes three criteria:

[0088] a) The first switch undervoltage protection function is activated.

[0089] b) First switch loss of voltage: The first switch changes from energized to de-energized (less than the de-energized setting), the switch is closed and there is no current (indicating that the upstream substation outlet circuit breaker has tripped).

[0090] c) No fault downstream of the first switch: undervoltage through current interlocking is engaged, no overcurrent memory (no overcurrent signal appears during the memory period).

[0091] For the primary switch, the primary switch undervoltage protection function generates two associated soft remote signals:

[0092] a) First switch undervoltage protection action: This indicates that the first switch undervoltage protection function of this terminal has started to act, and a trip signal is transmitted to the switch.

[0093] b) First switch undervoltage protection successful: This means that the first switch connected to this terminal has completed the first switch undervoltage protection function and the terminal has sensed the opening status through remote signaling.

[0094] 2.3 Recovery Function:

[0095] After fault isolation is completed using the isolation function or the first switch undervoltage protection function, the tie switch triggers the recovery function to restore power supply to the non-faulty area downstream of the fault point. The functional logic is as follows: Figure 5 After the action conditions are met, the action is performed after a delay. It mainly includes four criteria:

[0096] a) Basic criteria: The function is restored, communication is normal, the charging of the contact switch operating mechanism is completed (i.e., there is voltage on both sides), and the charging delay meets the conditions.

[0097] b) Loss of voltage criteria: Loss of voltage on one side of the tie switch (i.e., the opposite terminal is identified as having no voltage and informs this terminal), voltage on the line (i.e., whether the busbar on this side of the terminal has voltage), and loss of voltage on one side of both sides is considered a loss of voltage.

[0098] c) Isolation completion criteria: All switches related to the isolation of the fault area complete their operation and send signals indicating successful isolation and successful undervoltage protection of the first switch.

[0099] d) Overload criterion: Predict whether the load current brought about by closing this switch exceeds the line's carrying capacity. If it does, closing the switch is not allowed.

[0100] For the handshake switch, the recovery function generates two associated soft remote signals:

[0101] a) Recovery action: This indicates that the recovery function of this terminal has started to act, and a closing signal is transmitted to the tie switch.

[0102] b) Recovery successful: This means that the interconnection switch connected to this terminal has been closed, and the terminal has sensed the closing status through remote signaling.

[0103] 2.4 Switch Refusal to Operate Judgment Function:

[0104] If a switch that needs to be tripped fails to operate, its adjacent switch must be activated to expand the isolation range and isolate the faulty area. The functional logic is as follows: Figure 6 After a delay, the action is performed once the action conditions are met. This mainly includes two criteria: one for upstream and one for downstream faults.

[0105] a) As the first switch upstream of the fault point, the soft remote signal for isolation action was triggered, but the soft remote signal for successful isolation was not triggered (the switch still has current), and a switch failure signal was issued.

[0106] b) As the first switch downstream of the fault point, the soft remote signal for isolation action was triggered, but the soft remote signal for successful isolation was not triggered (the switch is still in the closed state), and a switch failure signal was issued.

[0107] For a switch that refuses to operate, this function generates one associated soft remote signal:

[0108] a) Switch fails to operate: This means that the switch connected to this terminal fails to operate.

[0109] 2.5 Malfunction Protection Function

[0110] When an abnormal judgment occurs, such as a switch refusing to operate, the terminal with the failure protection function will perform supplementary actions to ensure the isolation of the faulty area of ​​the line. The functional logic is as follows: Figure 7 After a delay, the action is performed once the action conditions are met. This mainly includes two criteria: one for upstream and one for downstream faults.

[0111] a) As the second switch upstream of the fault point, if the first switch upstream of the fault point fails to operate, this switch will trigger the failure protection and start the isolation logic.

[0112] b) As the second switch downstream of the fault point, if the first switch downstream of the fault point fails to operate, this switch will trigger the failure protection and start the isolation logic.

[0113] The failure protection function generates one associated soft remote signal:

[0114] a) Failure Protection Action: This indicates that the failure protection function of this terminal has been activated, and the isolation and other logic has been initiated.

[0115] 2.6 Lockout Function:

[0116] When an abnormality occurs in the distributed feeder automation communication, the function interlock logic is triggered, freezing all related action logic to ensure that the line does not experience unexpected actions. The function logic is as follows: Figure 8 As shown, for this switch or this station, when it is determined that a distributed feeder automation communication abnormality, switch failure to operate, distributed feeder automation isolation interlock, distributed feeder automation recovery interlock, or first switch undervoltage protection interlock occurs, the distributed feeder automation function is interlocked.

[0117] 2.7 Logic for determining successful isolation:

[0118] Functional logic such as Figure 9 As shown, after the distributed feeder automatic isolation action, the first switch undervoltage protection action, or the failure protection action, the corresponding switch is in the open position and there is no current, indicating that the protection action is successfully isolated.

[0119] The specific action logic of the distributed feeder automation function designed in this invention can be used in multiple operating scenarios such as distribution network branches, main lines, and substation outlet protection. It also takes into account the impact of abnormal disturbances such as switch failure to operate. The specific functions involved are comprehensive and effective, providing strong support for improving the practical application level of distribution automation and promoting the application of key technologies for distributed feeder automation.

[0120] Example 2:

[0121] This section uses a daisy-chain distribution network as an example to demonstrate specific application scenarios of distributed feeder automation. For example... Figure 10 As shown in the figure, the distributed feeder automation functions of the circuit breaker terminals are all in operation, communication between terminals is normal, circuit breaker 6 is a tie switch, and charging has been completed.

[0122] Mainline fault cases, such as Figure 11 As shown, a) when a short circuit / grounding fault occurs at position F3 of line, circuit breaker 2 detects the fault signal.

[0123] b) After determining that circuit breaker 2 and circuit breaker 5 meet the protection operation conditions, the distributed FA isolation operation function of #2 and #5 is triggered after a delay, and circuit breaker 2 and circuit breaker 5 are tripped, realizing the isolation of the fault area. The distributed FA isolation operation is successful.

[0124] c) At this time, ring main unit B loses power. Circuit breaker 6 detects that the switch loses power on one side. After the transfer conditions are met, the distributed FA recovery function is triggered after a delay. Circuit breaker 6 closes and the normal operating section of circuit breaker 7 is restored to power supply.

[0125] Cases of upstream faults of the first switch, such as Figure 12 As shown: a) A short circuit / ground fault occurs at position F6 on the line, and the downstream circuit breaker does not meet the protection operation conditions and does not trip. At this time, the outgoing circuit breaker B triggers the station's protection and trips.

[0126] b) When the first switch, i.e., circuit breaker 10, detects a line undervoltage signal, the first switch undervoltage protection function is triggered, and circuit breaker 10 trips to isolate the faulty section.

[0127] c) At this time, circuit breaker 6 meets the load transfer conditions, the distributed FA recovery function is activated, and power supply to the non-faulty area is restored.

[0128] Example 3:

[0129] Based on the same inventive concept, the present invention also provides a distributed feeder automated fault handling system comprising: interconnected power distribution line station terminals and circuit breakers;

[0130] The distribution line substation terminal is used to acquire the current, bus voltage, and circuit breaker status at the location of the circuit breaker connected to it, as well as the status of circuit breakers connected to other distribution line substation terminals; and to determine the fault point based on the current, bus voltage, and circuit breaker status at the location of the circuit breaker connected to it, combined with the status of circuit breakers connected to adjacent distribution line substation terminals; and to process the fault point.

[0131] The circuit breaker is installed on the power distribution line, and the user receives instructions from the terminal of the power distribution line station to perform opening and closing actions.

[0132] The substation terminal includes: a data acquisition module, a fault diagnosis module, and a fault processing module;

[0133] The data acquisition module is used to acquire the current, bus voltage and circuit breaker status at the location of the circuit breaker connected to the terminal of the substation, and transmit the current, bus voltage and circuit breaker status at the location of the circuit breaker to the fault judgment module.

[0134] The fault judgment module is used to judge the phase overcurrent and zero-sequence overcurrent of the current, and to determine whether the circuit breaker directly connected to the terminal of the distribution line station has phase overcurrent and zero-sequence overcurrent; to perform voltage identification on the bus side voltage, and to determine whether the bus where the terminal of the distribution line station is located is energized; based on its own phase overcurrent, zero-sequence overcurrent and the determination of whether the bus is energized, combined with the status of the circuit breaker connected to the terminal of the adjacent distribution line station, to determine the fault point, and to transmit the location of the fault point to the fault processing module;

[0135] The fault handling module is used to handle the fault point by means of isolation or first switch undervoltage protection based on the location of the fault point, and restore the power supply to the fault point after the fault is cleared.

[0136] It also includes current transformers and voltage transformers;

[0137] The current transformer is installed at the location of the circuit breaker to sense the current of the circuit breaker and transmit the current to the terminal of the substation.

[0138] The voltage transformer is installed at the busbar to sense the busbar voltage on its side and transmit the busbar voltage to the substation terminal.

[0139] The substation terminal is also used to isolate the fault point by delaying the tripping of the upstream and downstream circuit breakers of the fault point. When any one of the judgment conditions is met, it is judged that the circuit breaker fails to operate.

[0140] The judgment conditions include:

[0141] There is current after the circuit breaker upstream of the fault point triggers isolation action;

[0142] After the circuit breaker downstream of the fault point triggers the isolation action, the circuit breaker remains closed and current is present.

[0143] After the first switch triggers the undervoltage protection action, the first switch remains in the closed state and current is present.

[0144] The substation terminal is also specifically used for:

[0145] When the first circuit breaker upstream of the fault point fails to operate, the failure protection of the second circuit breaker upstream of the fault point is triggered, and the isolation logic is initiated.

[0146] When the first circuit breaker downstream of the fault point fails to operate, the failure protection of the second circuit breaker downstream of the fault point is triggered, and the isolation logic is initiated.

[0147] When the first switch fails to operate, the first switch is put into failure protection and the isolation logic is activated.

[0148] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0149] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0150] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0151] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0152] The above are merely embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of the claims of the present invention pending approval.

Claims

1. A method for automated fault handling of distributed feeders, characterized in that, include: The distribution line station terminal obtains the current at the location of the circuit breaker connected to it, the voltage on the bus side, and the status of the circuit breaker, as well as the status of the circuit breakers connected to other distribution line station terminals. The power distribution line station terminal performs phase overcurrent and zero-sequence overcurrent judgment on the current, and determines whether there is phase overcurrent and zero-sequence overcurrent in the circuit breaker directly connected to the power distribution line station terminal; The distribution line station terminal performs voltage identification on the bus side to determine whether the bus where the distribution line station terminal is located is energized; The fault point is determined by the distribution line station terminal based on its own phase overcurrent, zero-sequence overcurrent and whether the bus is energized, combined with the status of the circuit breaker connected to the adjacent distribution line station terminal. When the fault point is the first circuit breaker, the first switch undervoltage protection mode is activated to handle the fault point, and the first switch is closed after the fault is cleared. When the fault point is a circuit breaker on the main line, the circuit breakers upstream and downstream of the fault point are tripped with a time delay to isolate the fault point. After the fault is cleared, a closing signal is sent to the circuit breakers upstream and downstream of the fault point to restore power supply to the fault point.

2. The method as described in claim 1, characterized in that, The distribution line substation terminal obtains the current, bus voltage, and circuit breaker status at the location of the circuit breaker it is connected to, including: The distribution line station terminal senses the current of the circuit breaker based on the current transformer installed at the location of the circuit breaker, and senses the voltage of the bus on this side based on the voltage transformer installed at the bus. The power distribution line station terminal obtains the switching status of the circuit breaker directly connected to the power distribution line station terminal using either hard remote signaling or soft remote signaling.

3. The method as described in claim 1, characterized in that, Also includes: When the fault point is isolated by delay tripping of the upstream and downstream circuit breakers, the circuit breaker is judged to be refusing to operate if any of the judgment conditions are met.

4. The method as described in claim 3, characterized in that, The judgment conditions include: There is current after the circuit breaker upstream of the fault point triggers isolation action; After the circuit breaker downstream of the fault point triggers the isolation action, the circuit breaker remains closed and current is present. After the first switch triggers the undervoltage protection action, the first switch remains in the closed state and current is present.

5. The method as described in claim 3, characterized in that, It also includes, When the first circuit breaker upstream of the fault point fails to operate, the failure protection of the second circuit breaker upstream of the fault point is triggered, and the isolation logic is initiated. When the first circuit breaker downstream of the fault point fails to operate, the failure protection of the second circuit breaker downstream of the fault point is triggered, and the isolation logic is initiated. When the first switch fails to operate, the first switch is put into failure protection and the isolation logic is activated.

6. A distributed feeder automated fault handling system, characterized in that, include: Interconnected power distribution line stations, terminals, and circuit breakers; The distribution line substation terminal is used to acquire the current, bus voltage, and circuit breaker status at the location of the circuit breaker connected to it, as well as the status of circuit breakers connected to other distribution line substation terminals; and to determine the fault point based on the current, bus voltage, and circuit breaker status at the location of the circuit breaker connected to it, combined with the status of circuit breakers connected to adjacent distribution line substation terminals; and to process the fault point. The circuit breaker is installed on the power distribution line, and the user receives instructions from the power distribution line station terminal to perform opening and closing actions. The power distribution line station terminal includes: a data acquisition module, a fault judgment module, and a fault processing module; The data acquisition module is used to acquire the current, bus voltage and circuit breaker status at the location of the circuit breaker connected to the terminal of the power distribution line station, and transmit the current, bus voltage and circuit breaker status at the location of the circuit breaker to the fault judgment module. The fault judgment module is used to judge the phase overcurrent and zero-sequence overcurrent of the current, and to determine whether the circuit breaker directly connected to the terminal of the distribution line station has phase overcurrent and zero-sequence overcurrent; to perform voltage identification on the bus side voltage, and to determine whether the bus where the terminal of the distribution line station is located is energized; based on its own phase overcurrent, zero-sequence overcurrent and the determination of whether the bus is energized, combined with the status of the circuit breaker connected to the terminal of the adjacent distribution line station, to determine the fault point, and to transmit the location of the fault point to the fault processing module; The fault handling module is used to handle the fault point by means of isolation or first switch undervoltage protection based on the location of the fault point, and restore the power supply to the fault point after the fault is cleared.

7. The system according to claim 6, characterized in that, It also includes current transformers and voltage transformers; The current transformer is installed at the location of the circuit breaker to sense the current of the circuit breaker and transmit the current to the terminal of the distribution line station. The voltage transformer is installed at the busbar to sense the busbar voltage on its side and transmit the busbar voltage to the distribution line substation terminal.

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