A self-healing method for power distribution line faults

Abstract

The application provides a power distribution line fault self-recovery method, comprising the following steps: when a power distribution line fault occurs, a protection device of a power distribution switch controls a power distribution switch of a next stage in a fault area to trip according to a preset differential configuration strategy; a power distribution main station starts a preset self-recovery action and controls a preset differential protection cooperative feeder self-recovery action to process a line fault according to fault information sent by a power distribution terminal; whether the line fault is processed is judged according to a real-time collected line fault processing state, and when the line fault is processed, the power distribution main station determines that the self-recovery action is ended. The application meets the requirements of small power distribution line fault outage range and short fault disposal time, further optimizes the effectiveness of the feeder self-recovery action, and improves the power supply reliability.

Description

Technical Field

[0001] This invention relates to the field of self-healing technology for power distribution line faults, and in particular to a self-healing method for power distribution line faults. Background Technology

[0002] Currently, the self-healing of external feeders in distribution networks is mainly achieved through three methods: centralized, local, and coordinated. Among them, the local method mainly uses differential protection, voltage / current / time type, and intelligent distributed protection, while the coordinated method mainly uses the coordination between the master station and intelligent distributed protection, and the coordination between the master station and voltage / current / time type protection. From the perspectives of balancing the scope of power outages and the short duration of faults, all the above modes have certain drawbacks: 1. Centralized systems are characterized by high reliability, short response time, and ease of maintenance, but generally rely on the tripping of outgoing circuit breakers in substations to initiate fault handling, resulting in a large power outage area; 2. Differential protection local self-healing systems are characterized by a small power outage area, fast response, and ease of maintenance, but cannot achieve fault isolation in the smallest interval and restoration of power supply to upstream and downstream areas; 3. Voltage / current / time-based local self-healing systems are characterized by short response time and ease of maintenance, but generally rely on the tripping of outgoing circuit breakers in substations to initiate fault handling, resulting in a large power outage area; 4. Intelligent distributed local self-healing systems are characterized by high reliability and short response time, but the cost of maintenance is too high; 5. The combination of master station and intelligent distributed systems is characterized by high reliability and short response time, but the cost of maintenance is too high; 6. The combination of master station and voltage / current / time-based systems is characterized by high reliability, short response time, and ease of maintenance, but generally relies on the tripping of outgoing circuit breakers in substations to initiate fault handling, resulting in a large power outage area. Therefore, the current main feeder self-healing modes are all imperfect in meeting the requirements of small power outage range and short power outage time in power distribution line faults. Summary of the Invention

[0003] The purpose of this invention is to propose a self-healing method for power distribution line faults, thereby solving the technical problem that existing methods cannot meet the requirements of small power outage range and short power outage time for power distribution line faults.

[0004] On the one hand, a self-healing method for power distribution line faults is provided, including:

[0005] When a fault occurs in a power distribution line, the fault current flows through the protection device of the distribution network switch and controls the distribution network switch of the next higher level of differential protection in the fault area to trip according to the preset differential configuration strategy.

[0006] Based on the fault information sent by the distribution terminal, the distribution network master station initiates the preset self-healing action and simultaneously controls the preset differential protection to coordinate the feeder self-healing action to handle the line fault.

[0007] The system determines whether the line fault handling is complete based on the real-time collected line fault handling status. When the line fault handling is complete, the distribution network master station determines that the self-healing action has ended.

[0008] Preferably, the differential configuration strategy includes multiple strategy items corresponding to the power distribution protection device, and the strategy items limit the protection settings and protection action time limits of the power distribution protection device.

[0009] Preferably, the fault information sent by the power distribution terminal includes the tripping information of the power distribution switch and the protection action information of the power distribution switch.

[0010] Preferably, the step of activating a preset self-healing action and simultaneously controlling a preset differential protection coordinated feeder self-healing action to handle line faults specifically includes:

[0011] After the differential protection is activated, the distribution network master station collects complete fault information from all distribution terminals of the faulty line according to the preset delay time.

[0012] Based on the fault information, determine whether there is a sudden current drop in the tripped distribution network switch. If there is a sudden current drop, determine whether the tripped distribution network switch is locked for self-healing. If there is no sudden current drop, determine that the fault handling is complete.

[0013] Preferably, determining whether the tripped distribution network switch is locked for self-healing specifically includes:

[0014] Based on the fault information, determine whether the tripped distribution network switch meets the preset self-healing interlocking conditions. If it does, determine that self-healing interlocking is required and fault location is performed; if it does not, determine that the fault handling is completed.

[0015] Preferably, the fault location specifically includes:

[0016] The distribution network master station locates faults and determines the fault area based on the electrical topology connection relationship of the feeders and the fault information sent by the distribution terminals;

[0017] Based on the fault location results and whether the distribution network switch can be remotely controlled, determine the switches used to isolate the upstream and downstream of the fault. By controlling the remotely controlled distribution network switch, disconnect the upstream and downstream switches of the fault to complete the fault isolation.

[0018] Preferably, it further includes:

[0019] The distribution network master station determines the tie switch used to restore power supply to the downstream of the fault based on the electrical topology of the faulty line and whether the tie switch can be remotely controlled. The power supply to the downstream of the fault is restored by remotely controlling the tie switch.

[0020] The distribution network master station determines whether the tripped distribution network switch is the same as the switch used to isolate the upstream fault. If they are the same, it is determined that there is no upstream restoration plan; if they are not the same, the tripped distribution network switch is remotely closed to restore power supply to the upstream fault.

[0021] Preferably, the step of determining whether the line fault handling is completed based on the real-time collected line fault handling status specifically includes:

[0022] The distribution network master station monitors whether the closing switch used to restore power has been opened again;

[0023] If the circuit breaker trips again, the self-healing action is considered to have failed; if it does not trip again, the self-healing action is considered to have succeeded.

[0024] In summary, implementing the embodiments of the present invention has the following beneficial effects:

[0025] The self-healing method for power distribution line faults provided by this invention establishes a collaborative mechanism between the distribution network master station and differential protection. The local differential protection works together to achieve fault tripping nearby, while the master station completes fault location, fault isolation, power restoration to non-faulty areas, and self-healing action evaluation. The two work together to complete the self-healing of feeder faults, while meeting the requirements of small power outage range and short fault handling time for power distribution line faults. This further optimizes the effectiveness of feeder self-healing actions and improves power supply reliability. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, obtaining other drawings based on these drawings without creative effort still falls within the scope of the present invention.

[0027] Figure 1 This is a schematic diagram of the main process of a self-healing method for power distribution line faults in an embodiment of the present invention.

[0028] Figure 2 This is a logical schematic diagram of a self-healing method for power distribution line faults in an embodiment of the present invention. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings.

[0030] As shown in the figure and Figure 2 The diagram shown is a schematic representation of an embodiment of a self-healing method for power distribution line faults provided by the present invention. In this embodiment, the method includes the following steps:

[0031] When a fault occurs in a power distribution line, the fault current flows through the protection device of the power distribution network switch and controls the power distribution network switch of the upstream differential protection in the fault area to trip according to the preset differential protection configuration strategy; that is, a reasonable differential protection strategy is configured for different power distribution lines; when a fault occurs in a power distribution line, the fault current flows through the protection device of the power distribution network switch and realizes the tripping of the upstream first-level differential protection of the power distribution network switch in the fault area according to the differential protection configuration strategy.

[0032] In a specific embodiment, the differential configuration strategy includes multiple strategy items corresponding to the power distribution protection device, and the strategy items limit the protection settings and protection action time limits of the power distribution protection device.

[0033] Furthermore, based on the fault information sent by the distribution terminal, the distribution network master station initiates a preset self-healing action and simultaneously controls the preset differential protection to coordinate with the feeder self-healing action to handle line faults; that is, based on the fault information sent by the distribution terminal, the distribution network master station initiates differential protection and distribution network master station coordinated self-healing; and coordinates with differential protection to coordinate with the feeder self-healing function to handle line faults.

[0034] In a specific embodiment, the fault information sent by the power distribution terminal includes the tripping information of the power distribution switch and the protection action information of the power distribution switch.

[0035] Specifically, the process of initiating a preset self-healing action and simultaneously controlling a preset differential protection coordinated feeder self-healing action for line fault handling includes: after the differential protection action, the distribution network master station collects complete fault information from all distribution terminals of the faulty line according to a preset delay time; based on the fault information, it determines whether the tripped distribution network switch has a current surge; if there is a current surge, it determines whether the tripped distribution network switch should be locked for self-healing; if there is no current surge, it determines that the fault handling is complete. It can be understood that after the differential protection action, the distribution network master station, based on the configuration differential protection switch tripping and protection information sent by the distribution terminals, initiates differential protection and distribution network master station coordinated self-healing; the distribution network master station waits for a delay, collecting complete fault information from all distribution terminals of the faulty line; the distribution network master station determines whether the tripped switch has a current surge; if so, it proceeds to determine whether self-healing should be locked; otherwise, the analysis ends.

[0036] Specifically, determining whether the tripped distribution network switch is locked for self-healing includes: judging whether the tripped distribution network switch meets the preset self-healing lockout conditions based on the fault information. If it does, it is determined that self-healing lockout is required and fault location is performed; if it does not meet the conditions, the fault handling is determined to be completed. It is understandable that the distribution network master station determines whether self-healing lockout is required based on self-healing lockout conditions such as whether the tripped switch was caused by remote control or whether it has a self-healing lockout sign. If so, the analysis ends; otherwise, fault location is initiated.

[0037] More specifically, the fault location includes: the distribution network master station locates the fault based on the feeder electrical topology and the fault information sent by the distribution terminal, determining the fault area; based on the fault location result and whether the distribution network switches can be remotely controlled, the master station determines the switches used to isolate the upstream and downstream faults, and disconnects the upstream and downstream fault switches by controlling the remotely controlled distribution network switches to complete the fault isolation. In other words, the distribution network master station locates the fault based on the feeder electrical topology and the fault information sent by the distribution terminal, determining the fault area; based on the fault location result and whether the distribution network switches can be remotely controlled, the master station determines the switches used to isolate the upstream and downstream faults, and disconnects the upstream and downstream fault switches by remote control to complete the fault isolation.

[0038] More specifically, the distribution network master station determines the tie switch used to restore power to the downstream of the fault based on the electrical topology of the faulty line and whether the tie switch can be remotely controlled. Power restoration to the downstream is then completed via remote control of the tie switch. The master station then determines whether the tripped distribution switch is the same as the switch used to isolate the upstream of the fault. If they are the same, there is no upstream restoration plan; otherwise, the master station remotely closes the tripped distribution switch to restore power to the upstream of the fault. In essence, the process involves determining the tie switch used to restore power to the downstream of the fault based on the electrical topology of the faulty line and whether the tie switch can be remotely controlled. The master station then determines whether the tripped switch is the same as the switch used to isolate the upstream of the fault. If they are the same, there is no upstream restoration plan; otherwise, the master station remotely closes the tripped switch to restore power to the upstream of the fault.

[0039] Furthermore, the system determines whether the line fault handling is complete based on the real-time collected data on the line fault handling status. When the line fault handling is complete, the distribution network master station determines that the self-healing action has ended. Specifically, the distribution network master station monitors whether the closing switch used to restore power supply has been opened again; if it has been opened again, the self-healing action is determined to have failed; if it has not been opened again, the self-healing action is determined to have succeeded.

[0040] In summary, implementing the embodiments of the present invention has the following beneficial effects:

[0041] The self-healing method for power distribution line faults provided by this invention establishes a collaborative mechanism between the distribution network master station and differential protection. The local differential protection works together to achieve fault tripping nearby, while the master station completes fault location, fault isolation, power restoration to non-faulty areas, and self-healing action evaluation. The two work together to complete the self-healing of feeder faults, while meeting the requirements of small power outage range and short fault handling time for power distribution line faults. This further optimizes the effectiveness of feeder self-healing actions and improves power supply reliability.

[0042] The above description discloses only preferred embodiments of the present invention and should not be construed as limiting the scope of the present invention. Therefore, equivalent variations made in accordance with the claims of the present invention are still within the scope of the present invention.

Claims

1. A self-healing method for power distribution line faults, characterized in that, include: When a fault occurs in a power distribution line, the fault current flows through the protection device of the distribution network switch and controls the distribution network switch of the next higher level of differential protection in the fault area to trip according to the preset differential configuration strategy. The differential configuration strategy includes multiple strategy items corresponding to the power distribution protection device, and the strategy items limit the protection settings and protection action time of the power distribution device. Based on the fault information sent by the distribution terminal, the distribution network master station initiates the preset self-healing action and simultaneously controls the preset differential protection to coordinate the feeder self-healing action to handle the line fault. The system determines whether the line fault handling is complete based on the real-time collected line fault handling status. When the line fault handling is complete, the distribution network master station determines that the self-healing action has ended. The specific steps of initiating a preset self-healing action and simultaneously controlling a preset differential protection coordinated feeder self-healing action to handle line faults include: After the differential protection is activated, the distribution network master station collects complete fault information from all distribution terminals of the faulty line according to the preset delay time. Based on the fault information, determine whether there is a sudden current drop in the tripped distribution network switch. If there is a sudden current drop, determine whether the tripped distribution network switch meets the preset self-healing interlocking conditions based on the fault information. If it meets the conditions, determine that self-healing interlocking and fault location are required. If it does not meet the conditions, determine that the fault handling is completed. If there is no sudden current drop, determine that the fault handling is completed. The fault location specifically includes: The distribution network master station locates faults and determines the fault area based on the electrical topology connection relationship of the feeders and the fault information sent by the distribution terminals; Based on the fault location results and whether the distribution network switch can be remotely controlled, determine the switches used to isolate the upstream and downstream of the fault. By controlling the remotely controlled distribution network switch, disconnect the upstream and downstream switches of the fault to complete the fault isolation. The distribution network master station determines the tie switch used to restore power supply to the downstream of the fault based on the electrical topology of the faulty line and whether the tie switch can be remotely controlled. The power supply to the downstream of the fault is restored by remotely controlling the tie switch. The distribution network master station determines whether the tripped distribution network switch is the same as the switch used to isolate the upstream fault. If they are the same, it is determined that there is no upstream restoration plan; if they are not the same, the tripped distribution network switch is remotely closed to restore power supply to the upstream fault.

2. The method as described in claim 1, characterized in that, The fault information sent by the power distribution terminal includes the tripping information of the power distribution switch and the protection action information of the power distribution switch.

3. The method as described in claim 2, characterized in that, The step of determining whether the line fault handling is completed based on the real-time collected line fault handling status specifically includes: The distribution network master station monitors whether the closing switch used to restore power has been opened again; If the circuit breaker trips again, the self-healing action is considered to have failed; if it does not trip again, the self-healing action is considered to have succeeded.

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