A self-healing control method for short-circuit fault in power distribution system

Abstract

The present application discloses a self-healing control method for short-circuit faults in a power distribution system, wherein the power distribution system includes a first substation and a plurality of circuit breakers connected to the system trunk line, branch line, and boundary line; the method includes: dividing the power distribution system into a first distribution area and a second distribution area based on the distribution status of the power distribution system; setting corresponding short-circuit setting currents and delay times for the circuit breakers in the two areas; monitoring the actual currents of the circuit breakers in the first distribution area and the actual currents of the circuit breakers in the second distribution area; for the two distribution areas, identifying the short-circuit faults in the distribution area based on the actual currents, short-circuit setting currents, and delay times of the circuit breakers in the distribution area, and performing corresponding short-circuit fault isolation operations. The present application improves the response speed of the system, does not affect the normal power supply of other areas in the event of a local fault, and can achieve relatively accurate fault isolation.

Description

Technical Field

[0001] The present application relates to the technical field of distribution network fault processing, and in particular to a short-circuit fault self-healing control method for a distribution system. Background Art

[0002] As a key link in power distribution, the stability and safety of the power distribution system are crucial to ensuring power supply. However, due to the complex structure, numerous devices, and changing operating environment of the power distribution system, short-circuit faults often occur. Short-circuit faults not only cause equipment damage but may also cause serious consequences such as fire. Therefore, effective control of short-circuit faults in the power distribution system is particularly important.

[0003] In existing technologies, when a short circuit occurs in a power distribution system, the circuit breaker at the substation exit is typically activated to stop the entire line. The fault is then located based on the collected FTU information, and power is restored after the fault location is identified. However, this method has the following technical problems:

[0004] 1) When a short circuit occurs in the line, the system responds slowly and the system power outage lasts relatively long. 2) Accurate fault isolation cannot be achieved, and the system power supply reliability is low. Summary of the Invention

[0005] In order to solve one or more of the above technical problems, the present application provides a short circuit fault self-healing control method for a power distribution system.

[0006] In a first aspect, the present application provides a short-circuit fault self-healing control method for a power distribution system, which adopts the following technical solution:

[0007] A short-circuit fault self-healing control method for a power distribution system, the power distribution system comprising a first substation and a plurality of circuit breakers connected to a trunk line, branch lines, and boundary lines of the power distribution system; wherein the power distribution system is connected to a second substation via a tie circuit breaker LS; the self-healing control method comprising:

[0008] Based on the distribution status of the power distribution system, the power distribution system is divided into a first power distribution area and a second power distribution area;

[0009] Respectively set the short-circuit setting current and delay time corresponding to the circuit breaker in the first distribution area, and the short-circuit setting current and closing delay time corresponding to the circuit breaker in the second distribution area;

[0010] monitoring an actual current of a circuit breaker in the first distribution area and an actual current of a circuit breaker in the second distribution area;

[0011] Based on the actual current, short-circuit setting current and delay time of the circuit breaker in the first distribution area, the short-circuit fault in the first distribution area is identified, and the corresponding short-circuit fault isolation operation is performed; based on the actual current, short-circuit setting current and delay time of the circuit breaker in the second distribution area, the short-circuit fault in the second distribution area is identified, and the corresponding short-circuit fault isolation operation is performed.

[0012] By adopting the above technical solution, the power distribution system is divided into a first distribution area and a second distribution area, and parameters such as the short-circuit setting current and delay time of the circuit breakers in each area are set respectively, and the actual current data of the circuit breakers in each area are monitored in real time. The two areas are set independently, and different processing methods are adopted to perform the corresponding short-circuit fault isolation operation in combination with instantaneous quick-break protection and time-limited quick-break protection. The method of first isolating and then analyzing is adopted for short-circuit faults, which not only improves the response speed of the system, but also does not affect the normal power supply of other areas in the event of a local fault, and can achieve more accurate fault isolation, thereby improving the reliability of the power distribution system and realizing efficient self-healing of the power distribution system.

[0013] In a specific implementation scheme, based on the actual current, short-circuit setting current, and delay time of the circuit breaker in the first distribution area, identifying the short-circuit fault in the first distribution area and performing the corresponding short-circuit fault isolation operation specifically includes:

[0014] If the actual current of a circuit breaker on the main line of the first distribution area exceeds the corresponding short-circuit setting current, and the actual current exceeds the corresponding short-circuit setting current for a duration equal to the corresponding delay time, the circuit breaker is marked as a faulty circuit breaker. The faulty circuit breaker and the downstream adjacent circuit breaker are controlled to open to isolate the faulty area, and the tie circuit breaker LS is remotely closed to restore power to the non-faulty area through the first substation and the second substation.

[0015] If the actual current of a circuit breaker located on a branch line or boundary line in the first distribution area exceeds the corresponding short-circuit setting current, and the duration of the actual current exceeding the corresponding short-circuit setting current reaches the corresponding delay time, the circuit breaker will be marked as a faulty circuit breaker; and the faulty circuit breaker will be controlled to open to isolate the faulty area, and power supply to the non-faulty area will be restored through the first substation.

[0016] By adopting the above technical solution, when a short circuit fault occurs in the first distribution area, accurate isolation of the fault area and normal power supply to the non-fault area can be achieved by setting the short-circuit setting current and delay time of each circuit breaker.

[0017] In a specific possible implementation scheme, based on the actual current, short-circuit setting current, and delay time of the circuit breaker in the second distribution area, identifying the short-circuit fault in the second distribution area and performing the corresponding short-circuit fault isolation operation specifically includes:

[0018] Marking the circuit breakers in the second power distribution area whose actual current exceeds the corresponding short-circuit setting current as circuit breakers to be identified again;

[0019] Record the time t when the actual current of the circuit breaker to be identified exceeds the corresponding short-circuit setting current a , and perform the opening and isolating operation on the circuit breakers to be identified in sequence from downstream to upstream until the current of the power distribution system returns to normal, the fault location is determined, and the fault area is isolated;

[0020] The opening and isolating operation includes: at the time t corresponding to the circuit breaker to be identified twice a When the corresponding delay time is reached, the circuit breaker to be identified for the second time is controlled to open.

[0021] By adopting the above technical solution, a multi-level judgment method is adopted for fault determination in the second power distribution area, and the corresponding circuit breakers are gradually disconnected to ensure normal power supply to the non-fault area to the greatest extent.

[0022] In a specific possible implementation scheme, after determining the fault location, the method further includes:

[0023] If the fault location is on the trunk line of the power distribution system and is not at the end of the trunk line of the power distribution system, the tie circuit breaker LS is remotely closed; and power supply to the non-fault area is restored through the first substation and the second substation.

[0024] In a specific implementation scheme, the delay time difference corresponding to adjacent upstream and downstream circuit breakers in the first power distribution area is Δt1; the delay time difference corresponding to adjacent upstream and downstream circuit breakers in the second power distribution area is Δt2;

[0025] Among them, △t1>△t2.

[0026] In a specific feasible implementation scheme, the short-circuit setting currents corresponding to the circuit breakers in the first distribution area are different, and the short-circuit setting currents corresponding to the circuit breakers in the second distribution area are the same.

[0027] In a specific feasible implementation scheme, the multiple circuit breakers connected to the main lines, branch lines and boundary lines of the power distribution system are all permanent magnetic circuit breakers.

[0028] In the second aspect, the present application provides a terminal comprising: a processor, a memory and a communication bus; the communication bus is used to realize connection and communication between the processor and the memory, and the processor is used to execute one or more programs stored in the memory to realize the distribution system short-circuit fault self-healing control method as described in the above-mentioned first aspect or any possible implementation scheme of the first aspect.

[0029] In a third aspect, the present application provides a computer-readable storage medium storing instructions. When the instructions are executed, the distribution system short-circuit fault self-healing control method as described in the first aspect or any possible implementation scheme of the first aspect is executed.

[0030] One or more technical solutions provided in the embodiments of this application have at least the following technical effects or advantages:

[0031] By dividing the power distribution system into the first distribution area and the second distribution area, and setting parameters such as the short-circuit setting current and delay time of the circuit breakers in each area respectively, and monitoring the actual current data of the circuit breakers in each area in real time, the two areas are set independently, combined with instantaneous quick-break protection and time-limited quick-break protection, and different processing methods are used to perform the corresponding short-circuit fault isolation operation; for short-circuit faults, the method of isolation first and then analysis is adopted, which not only improves the response speed of the system, but also does not affect the normal power supply of other areas in the event of a local fault. It can also achieve more accurate fault isolation, improve the reliability of the power distribution system, and realize efficient self-healing of the power distribution system. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 is a structural diagram of a power distribution system in an embodiment of the present application;

[0033] Figure 2 1 is a flow chart of a short-circuit fault self-healing control method for a power distribution system according to an embodiment of the present application;

[0034] Figure 3 This is a schematic diagram of a situation in which a fault occurs in the trunk line of the first power distribution area in an embodiment of the present application;

[0035] Figure 4 This is a schematic diagram of a branch line in the first power distribution area when a fault occurs in an embodiment of the present application;

[0036] Figure 5 This is a schematic diagram of a case where a fault occurs downstream of the second power distribution area FB4 in an embodiment of the present application;

[0037] Figure 6 This is a schematic diagram of a case where a fault occurs downstream of the second power distribution area FB3 in an embodiment of the present application;

[0038] Figure 7It is a schematic diagram of setting up a simulation environment in an embodiment of the present application. DETAILED DESCRIPTION

[0039] In order to enable those skilled in the art to better understand the technical solutions in this specification, the technical solutions in the embodiments of this specification will be clearly and completely described below in conjunction with the drawings in the embodiments of this specification. Obviously, the described embodiments are only part of the embodiments of this application, not all of the embodiments.

[0040] In the description of the embodiments of this application, words such as "for example" or "for instance" are used to indicate examples, illustrations, or explanations. Any embodiment or design described as "for example" or "for instance" in the embodiments of this application should not be construed as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "for example" or "for instance" is intended to present the relevant concepts in a concrete manner.

[0041] In the description of the embodiments of the present application, the term "multiple" means two or more. For example, multiple systems refer to two or more systems, and multiple screen terminals refer to two or more screen terminals. In addition, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the indicated technical features. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized.

[0042] The present application provides a method for controlling short-circuit fault self-healing in a power distribution system. Figure 1 As shown, the distribution system includes a first substation, and multiple circuit breakers connected to the main lines, branch lines and boundary lines of the distribution system, and also includes an export circuit breaker CB1 located at the export of the first substation; wherein, the distribution system is also connected to the second substation through a connecting circuit breaker LS; those skilled in the art will understand that a connecting circuit breaker LS is connected between the two distribution systems; normally, the connecting circuit breaker LS is in the open state, and the corresponding distribution system is powered by the first substation. When a failure occurs in the distribution system, the second substation will also be used for temporary power supply.

[0043] Preferably, the outlet circuit breaker CB1 can be a universal circuit breaker, a plastic case circuit breaker, a vacuum circuit breaker, a sulfur hexafluoride circuit breaker, etc.; among them, the universal circuit breaker is usually used in occasions with higher rated voltages, and the plastic case circuit breaker may be slightly inferior to the universal circuit breaker in terms of rated voltage and breaking capacity, but is also widely used in some medium and low voltage power distribution systems. Vacuum circuit breakers and sulfur hexafluoride circuit breakers have higher insulation performance and breaking capacity and can be used in occasions with extremely high performance requirements; for the selection of the outlet circuit breaker CB1, those skilled in the art can make comprehensive considerations based on the actual situation of the first substation, and this application does not make specific restrictions on this.

[0044] Preferably, the multiple circuit breakers connected to the main lines, branch lines and boundary lines of the power distribution system are all permanent magnetic circuit breakers with relatively fast opening and closing speeds.

[0045] like Figure 2 As shown, the self-healing control method of this embodiment includes steps S1-S4.

[0046] S1, dividing the power distribution system into a first power distribution area and a second power distribution area based on the distribution status of the power distribution system;

[0047] Specifically, based on the distribution status of the power distribution system, a power distribution area division node is determined; and then based on the power distribution area division node, the power distribution system is divided into a first power distribution area and a second power distribution area.

[0048] The following method can be adopted: taking the first substation as the reference point, the point on the distribution system trunk line that is a first preset distance away from the first substation is determined as the distribution area division node, for example, the 60% and 40% division points in the entire trunk line are used as division nodes; the area between the outlet circuit breaker CB1 and the area division node is divided into the first distribution area, and the area downstream of the area division node is divided into the second distribution area.

[0049] S2, respectively setting the short-circuit setting current and delay time corresponding to the circuit breaker in the first distribution area, and the short-circuit setting current and closing delay time corresponding to the circuit breaker in the second distribution area.

[0050] Furthermore, step S2 may specifically include setting a set current and a delay time corresponding to a circuit breaker located on a trunk line in the first power distribution area.

[0051] by Figure 1Take the system in as an example to explain, the first distribution area includes the first section circuit breaker FS1 and the second section circuit breaker FS2 located on the main line, and also includes the first first-level branch circuit breaker FB1 and the seventh first-level branch circuit breaker FB7 located on the branch line; wherein, the first section circuit breaker FS1 is upstream of the second section circuit breaker FS2; the seventh first-level branch circuit breaker FB7 is connected to the line between the outlet circuit breaker CB1 and the first section circuit breaker FS1, and the first first-level branch circuit breaker FB1 is connected to the line between the first section circuit breaker FS1 and the second section circuit breaker FS2; those skilled in the art can understand that the ends of the first first-level branch circuit breaker FB1 and the seventh first-level branch circuit breaker FB7 are connected to the load.

[0052] Among them, for the second section circuit breaker FS2, its short-circuit setting current can be set to 200A and the delay time can be set to 0.2s; for the first section circuit breaker FS1, its short-circuit setting current can be set to 600A and 0s.

[0053] Through the above settings, it can be seen that: for the circuit breakers in the first distribution area, the short-circuit setting currents set are different; and the delay time interval between the two section circuit breakers is 0.1s.

[0054] Continue with Figure 1 Taking the system in as an example, the second distribution area includes a third section circuit breaker FS3 located on the main line, and the third section circuit breaker FS3 is connected to the second substation through the connecting circuit breaker LS; the second distribution area also includes a third primary branch circuit breaker FB3, a first secondary branch circuit breaker FB4, a second secondary branch circuit breaker FB5 and a first boundary circuit breaker FB6 located on the branch line; wherein, one end of the third primary branch circuit breaker FB3 is connected to the line between the third section circuit breaker FS3 and the connecting circuit breaker LS, and the other end is respectively connected to one end of the first secondary branch circuit breaker FB4 and one end of the second secondary branch circuit breaker FB5; the other end of the first secondary branch circuit breaker FB4 is connected to the first boundary circuit breaker FB6.

[0055] Among them, for the circuit breakers in the second distribution area, the short-circuit setting current and the closing delay time can be set according to the multi-level differential protection rules; for example, for the first boundary circuit breaker FB6, its short-circuit setting current can be set to 150A and the delay time can be set to 0s; for the first secondary branch circuit breaker FB4, its short-circuit setting current can be set to 200A and the delay time can be set to 0.05s; for the second secondary branch circuit breaker FB5, its short-circuit setting current can be set to 150A and the delay time can be set to 0s; for the third primary branch circuit breaker FB3, its short-circuit setting current can be set to 200A and the delay time can be set to 0.1s; for the third segment circuit breaker FS3, its short-circuit setting current can be set to 200A and the delay time can be set to 0.15s. That is to say, in Figure 1 In the system shown, multi-level differential protection is set at FB6, FB4 and FB5, FB3 and FS3, and the delay times are 0s, 0.05s, 0.1s and 0.15s respectively.

[0056] From the above settings, it can be seen that: for the circuit breakers in the second distribution area, the short-circuit setting current is set to be the same; and the delay time is set in stages according to a fixed step difference of 0.05s.

[0057] In a possible implementation manner, the delay time difference corresponding to adjacent upstream and downstream circuit breakers in the first power distribution area is Δt1; the delay time difference corresponding to adjacent upstream and downstream circuit breakers in the second power distribution area is Δt2;

[0058] Among them, △t1>△t2; for example, △t1 is 0.1s, and △t2 is 0.05s.

[0059] Furthermore, the short-circuit setting currents corresponding to the circuit breakers in the first distribution area are different, and the short-circuit setting currents corresponding to the circuit breakers in the second distribution area are the same.

[0060] Since the line between the first distribution area and the first substation is shorter, the short-circuit current is larger when a fault occurs. The short-circuit fault can be identified more accurately by the current returning to the outlet circuit breaker CB1. By monitoring the actual current of each circuit breaker in the first distribution area, the fault location can be accurately isolated. However, the line between the second distribution area and the first substation is longer, and the short-circuit current is relatively smaller when a fault occurs. The short-circuit fault can no longer be accurately identified by the current returning to the outlet circuit breaker CB1. Therefore, for the second distribution area, a step-by-step tripping method is adopted to accurately isolate the fault location.

[0061] In particular, those skilled in the art may set the specific values ​​of the set currents of the circuit breakers according to the actual conditions of the circuit, and this application does not impose any specific limitation on this.

[0062] S3, monitoring the actual current of the circuit breaker in the first distribution area and the actual current of the circuit breaker in the second distribution area.

[0063] S4, identifying a short-circuit fault in the first distribution area based on the actual current, short-circuit setting current, and delay time of the circuit breaker in the first distribution area, and performing a corresponding short-circuit fault isolation operation;

[0064] Based on the actual current, short-circuit setting current and delay time of the circuit breaker in the second distribution area, the short-circuit fault in the second distribution area is identified, and a corresponding short-circuit fault isolation operation is performed.

[0065] In a possible implementation, after executing the corresponding short-circuit fault isolation operation in step S4 , the step further includes: initiating analysis based on data of the fault location.

[0066] In a possible implementation, step S4 identifies the short-circuit fault in the first distribution area based on the actual current, short-circuit setting current, and delay time of the circuit breaker in the first distribution area, and performs a corresponding short-circuit fault isolation operation, specifically including steps A1-A2.

[0067] A1: If the actual current of a circuit breaker on the main line of the first distribution area exceeds the corresponding short-circuit setting current, and the actual current exceeds the corresponding short-circuit setting current for a duration equal to the corresponding delay time, the circuit breaker is marked as a faulty circuit breaker. The faulty circuit breaker and the downstream adjacent circuit breaker are controlled to open to isolate the faulty area, and the tie circuit breaker LS is remotely closed to restore power to the non-faulty area through the first and second substations.

[0068] The following combination Figure 3 Explain, such as Figure 3 As shown, if the actual current in the first segment circuit breaker FS1 exceeds the corresponding short-circuit setting current for a duration equal to the corresponding delay time, the first segment circuit breaker FS1, the second segment circuit breaker FS2, and the first primary branch circuit breaker FB1 are controlled to open, and the tie circuit breaker LS is remotely closed. This isolates the faulty area, and restores power to the non-faulty areas through the first and second substations. In this case, the normal power supply to the loads downstream of FB7 is not affected.

[0069] A2: If the actual current of a circuit breaker located on a branch line or boundary line in the first distribution area exceeds the corresponding short-circuit setting current, and the duration of the actual current exceeding the corresponding short-circuit setting current reaches the corresponding delay time, the circuit breaker is marked as a faulty circuit breaker; the faulty circuit breaker is controlled to open to isolate the faulty area, and power supply to the non-faulty area is restored through the first substation.

[0070] The following combination Figure 4 Explain, such as Figure 4 As shown, if the actual current of the first primary branch circuit breaker FB1 exceeds the corresponding short-circuit setting current and lasts for the corresponding delay time, the first primary branch circuit breaker FB1 is controlled to open, isolating the faulty area and restoring power to the non-faulty areas through the first substation. In this case, the first substation can still meet the power needs of the non-faulty areas of the distribution system, eliminating the need for a second substation.

[0071] Through the above steps A1-A2, when a short circuit fault occurs in the first distribution area, accurate isolation of the fault area and normal power supply to the non-fault area can be achieved by setting the short circuit setting current and delay time of each circuit breaker.

[0072] In one possible implementation, step S4 identifies the short-circuit fault in the second distribution area based on the actual current, short-circuit setting current, and delay time of the circuit breaker in the second distribution area, and performs corresponding short-circuit fault isolation operations, specifically including steps B1-B2.

[0073] B1, marking the circuit breaker whose actual current in the second distribution area exceeds the corresponding short-circuit setting current as a circuit breaker to be identified again;

[0074] B2, record the time t when the actual current of the circuit breaker to be identified exceeds the corresponding short-circuit setting current a and sequentially perform opening and isolating operations on the circuit breakers to be identified from downstream to upstream until the current in the power distribution system returns to normal, thereby determining the fault location and isolating the fault area. Here, the current in the power distribution system returns to normal if, excluding the circuit breaker that performs the opening and isolating operation, the actual currents of the remaining circuit breakers in the power distribution system are all lower than the corresponding short-circuit setting currents, indicating that the current in the power distribution system has returned to normal.

[0075] The opening and isolating operation includes: at the time t corresponding to the circuit breaker to be identified twice a When the corresponding delay time is reached, the circuit breaker to be identified for the second time is controlled to open.

[0076] The following combination Figure 5 Explanation of the above process:

[0077] like Figure 5As shown, if the fault location is downstream of FB4, it can be detected that the actual currents of FB6, FB4, FB3, and FS3 all exceed the corresponding short-circuit setting current, that is, exceed 200A. In this case, FB6, FB4, FB3, and FS3 are all marked as circuit breakers to be identified again. Next, the opening and isolation operation begins from FB6. Since the delay time corresponding to FB6 is 0s, FB6 is directly controlled to open. Since the delay time corresponding to FB4 is 0.05s, after waiting for 0.05s, FB4 is controlled to open. Since the current of the distribution system returns to normal after FB4 opens, the actual currents of FB3 and FS3 return to below the short-circuit setting current, so the fault location can be determined to be downstream of FB4. At this point, the fault area is also isolated.

[0078] like Figure 6 As shown, similarly, if the fault location is downstream of FB3, then FB6, FB4, FB5, and FB3 are all opened to isolate the fault area, which will not be described in detail here.

[0079] In a possible implementation manner, after determining the fault location in step B2, the following steps are further included:

[0080] If the fault is located on the distribution system's main line and is not at the end of the distribution system's main line, the tie circuit breaker LS is remotely closed, and power is restored to the non-faulty area via the first and second substations. It will be appreciated that if the fault is located at the end of the distribution system's main line, remote closing of the tie circuit breaker LS is unnecessary, and power from the second substation cannot reach the distribution system corresponding to the first substation.

[0081] Therefore, through the above steps B1-B2, a multi-level judgment method is adopted for the fault determination of the second power distribution area, and the corresponding circuit breakers are gradually disconnected to ensure the normal power supply of the non-fault area to the greatest extent.

[0082] Steps S1-S4 divide the power distribution system into a first distribution area and a second distribution area, and set parameters such as the short-circuit setting current and delay time of the circuit breakers in each area respectively, and monitor the actual current data of the circuit breakers in each area in real time. The two areas are set independently, combined with instantaneous quick-break protection and time-limited quick-break protection, and different processing methods are used to perform corresponding short-circuit fault isolation operations; for short-circuit faults, the method of first isolating and then analyzing is adopted, which not only improves the response speed of the system, but also does not affect the normal power supply of other areas in the event of a local fault, and can achieve more accurate fault isolation, thereby improving the reliability of the power distribution system and realizing efficient self-healing of the power distribution system.

[0083] Compared to the traditional method of first stopping the power supply of the entire line and then locating the fault based on the collected information of each FTU, this solution first accurately isolates the fault and then starts FA analysis. This ensures that when a line fault occurs, the power supply to the non-fault area is not interrupted, greatly improving power supply reliability.

[0084] In addition, the circuit breaker in this application adopts a permanent magnetic circuit breaker, which has the characteristics of small discrete type of opening and fast time of clearing the whole group of faults. The step difference of the permanent magnetic circuit breaker in the second distribution area is set to 0.05s, so for Figure 1 In this system, a three-phase, in-line permanent magnet circuit breaker group can achieve a fault-clearing time of less than 25ms. For the outlet circuit breaker CB1, since it is managed by the substation department and distribution coordination is complex, its delay time can be set to 0.4s. This allows the fault to be cleared directly by opening and closing the circuit breaker within the second distribution area, avoiding the operation of the outlet circuit breaker CB1.

[0085] The power distribution system short-circuit fault self-healing control method described in the embodiment of the present application can be used in 10kV medium-voltage distribution network lines, and is suitable for overhead line networks, cable lines, or a combination of the two line grid structures. This technology is particularly suitable for scenarios where the power supply level requirement is Class A. It can minimize the scope of power outages and shorten the duration of faults, and has a qualitative improvement in the self-healing solution of urban / rural medium-voltage distribution networks. Since laboratory simulation tests are required before actual commissioning, the power distribution system short-circuit fault self-healing control method described in this embodiment can be used in the simulation test stage, such as Figure 7 As shown in the figure, when setting up the simulation environment, a network is formed by permanent magnet fast circuit breakers, and all primary side input and output terminals are connected by copper bars. Impedance elements simulating actual lines are connected in series in the copper bars to restore the actual distribution network lines to the greatest extent. The FTUs corresponding to all circuit breakers and the test equipment are in the same local area network. The test equipment uniformly sends the FTU protection settings and FA parameters at different locations, and uses different current values ​​of the large current generator to simulate current faults at various locations, thereby performing simulation tests.

[0086] An embodiment of the present application provides a terminal, including: a processor, a memory and a communication bus; the communication bus is used to realize connection and communication between the processor and the memory, and the processor is used to execute one or more programs stored in the memory to implement the distribution system short-circuit fault self-healing control method described in the above embodiment.

[0087] An embodiment of the present application provides a computer-readable storage medium, which stores instructions. When the instructions are executed, the power distribution system short circuit fault self-healing control method described in the above embodiment is executed.

[0088] The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A short circuit fault self-healing control method for a power distribution system, characterized in that: The power distribution system includes a first substation and a plurality of circuit breakers connected to a trunk line, a branch line, and a boundary line of the power distribution system; wherein the power distribution system is connected to a second substation via a tie circuit breaker LS; and the self-healing control method includes: Based on the distribution status of the power distribution system, determine a point on the trunk line that is a first preset distance away from the first substation as a power distribution area division node, and divide the power distribution system into a first power distribution area and a second power distribution area based on the power distribution area division node; The short-circuit setting current and delay time corresponding to the circuit breakers in the first distribution area and the short-circuit setting current and delay time corresponding to the circuit breakers in the second distribution area are set respectively; the delay time of each circuit breaker in the second distribution area increases in a fixed step from downstream to upstream; monitoring an actual current of a circuit breaker in the first distribution area and an actual current of a circuit breaker in the second distribution area; Based on the actual current, short-circuit setting current, and delay time of the circuit breakers in the first distribution area, identify the short-circuit fault in the first distribution area and perform the corresponding short-circuit fault isolation operation; based on the actual current, short-circuit setting current, and delay time of the circuit breakers in the second distribution area, identify the short-circuit fault in the second distribution area and perform the corresponding short-circuit fault isolation operation; The short circuit fault isolation operation performed on the first power distribution area includes: If the actual current of a circuit breaker on a trunk line exceeds the corresponding short-circuit setting current, and the duration of the actual current exceeding the short-circuit setting current reaches the corresponding delay time, the circuit breaker and the downstream adjacent circuit breaker are controlled to open; If the actual current of a circuit breaker located on a branch line or a boundary line exceeds the corresponding short-circuit setting current, and the duration of the actual current exceeding the short-circuit setting current reaches the corresponding delay time, the circuit breaker is controlled to open; The short-circuit fault isolation operation performed on the second distribution area includes: The circuit breaker whose actual current exceeds the corresponding short-circuit setting current is marked as a circuit breaker to be identified twice; For the circuit breakers to be identified for the second time, the circuit breakers to be identified for the second time are controlled to open in sequence when the actual current exceeds the corresponding short-circuit setting current and the duration of the actual current exceeding the corresponding short-circuit setting current reaches the corresponding delay time until the current of the distribution system returns to normal.

2. The power distribution system short circuit fault self-healing control method according to claim 1, characterized in that: The short circuit fault isolation operation performed on the first power distribution area further includes: After controlling the circuit breaker and the downstream adjacent circuit breaker to open, the fault area is isolated, and the tie circuit breaker LS is remotely closed to restore power supply to the non-fault area through the first substation and the second substation; After the circuit breaker is controlled to open, the fault area is isolated and power supply to the non-fault area is restored through the first substation.

3. The power distribution system short circuit fault self-healing control method according to claim 1, characterized in that: The short circuit fault isolation operation performed on the second power distribution area further includes: After the current in the distribution system returns to normal, the fault location is determined and the fault area is isolated.

4. The power distribution system short circuit fault self-healing control method according to claim 3, characterized in that: After the fault location is determined, the following steps are also required: If the fault location is on the trunk line of the power distribution system and is not at the end of the trunk line of the power distribution system, the tie circuit breaker LS is remotely closed; and power supply to the non-fault area is restored through the first substation and the second substation.

5. The power distribution system short circuit fault self-healing control method according to claim 1, characterized in that: The delay time difference corresponding to adjacent upstream and downstream circuit breakers in the first power distribution area is Δt1; the delay time difference corresponding to adjacent upstream and downstream circuit breakers in the second power distribution area is Δt2; Among them, △t1>△t2.

6. The power distribution system short circuit fault self-healing control method according to claim 1, characterized in that: The short-circuit setting currents corresponding to the circuit breakers in the first distribution area are different, and the short-circuit setting currents corresponding to the circuit breakers in the second distribution area are the same.

7. The power distribution system short circuit fault self-healing control method according to claim 1, characterized in that: The multiple circuit breakers connected to the main lines, branch lines and boundary lines of the distribution system are all permanent magnet circuit breakers.

8. A terminal, characterized in that: include: A processor, a memory and a communication bus; the communication bus is used to realize connection and communication between the processor and the memory, and the processor is used to execute one or more programs stored in the memory to implement the distribution system short-circuit fault self-healing control method as described in any one of claims 1 to 7.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores instructions, and when the instructions are executed, the power distribution system short circuit fault self-healing control method according to any one of claims 1 to 7 is executed.

Images