Short-circuit fault self-healing control method for power distribution system

Abstract

The invention discloses a short-circuit fault self-healing control method for a power distribution system. The power distribution system comprises a first transformer substation and a plurality of circuit breakers connected to a main line, branch lines and boundary lines of the system. The method comprises the steps of dividing a power distribution system into a first power distribution area and a second power distribution area based on the distribution condition of the power distribution system; respectively setting corresponding short-circuit setting current and delay time for the circuit breakers in the two areas; monitoring the actual current of the circuit breaker in the first power distribution area and the actual current of the circuit breaker in the second power distribution area; and for the two power distribution areas, identifying a short-circuit fault of the power distribution area based on the actual current, the short-circuit setting current and the delay time of the circuit breaker in the power distribution area, and executing corresponding short-circuit fault isolation operation. According to the invention, the response speed of the system is improved, normal power supply of other areas is not affected when a local fault occurs, and accurate fault isolation can be realized.

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 the distribution of electric energy, the stability and safety of the distribution system are crucial to ensuring the supply of electricity. However, due to the complex structure of the distribution system, the large number of devices, and the changing operating environment, short-circuit failures occur from time to time. Short-circuit failures not only cause equipment damage, but may also cause serious consequences such as fire. Therefore, effective control of short-circuit failures in the distribution system is particularly important; In the prior art, when a short circuit occurs in a power distribution system, the circuit breaker at the substation exit is usually activated to stop the entire line, and then the fault is located based on the collected FTU information, and the power supply is restored after the fault location is identified. However, this method has the following technical problems: 1) When a short circuit occurs in the line, the system responds slowly and the system power outage lasts for a relatively long time; 2) It is impossible to achieve more accurate fault isolation and the system power supply reliability is low. Summary of the invention

[0003] 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.

[0004] 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: 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, 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; the self-healing control method comprising: 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; 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; Monitoring the actual current of the circuit breakers in the first distribution area and the actual current of the circuit breakers in the second distribution area; 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.

[0005] By adopting the above technical scheme, the distribution system is divided into a first distribution area and a second distribution area, and the short-circuit setting current, delay time and other parameters 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 isolation first and then analysis is adopted for short-circuit faults, which not only improves the response speed of the system, but also will not affect the normal power supply of other areas in the event of local faults, and can achieve more accurate fault isolation, thereby improving the reliability of the distribution system and realizing efficient self-healing of the distribution system.

[0006] In a specific feasible 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: If the actual current of the circuit breaker located on the main line of the first power distribution area exceeds the corresponding short-circuit setting current, and the actual current exceeds the corresponding short-circuit setting current for a duration that reaches 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 supply to the non-faulty area through the first substation and the second substation; 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, so as to isolate the faulty area and restore power supply to the non-faulty area through the first substation.

[0007] 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.

[0008] In a specific feasible implementation scheme, 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 of the second distribution area is identified, and the corresponding short-circuit fault isolation operation is performed, which specifically includes: 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 twice; Record the time t when the actual current of the circuit breaker to be identified exceeds the corresponding short-circuit setting current a, and in order from downstream to upstream, perform the opening and isolating operation on the circuit breakers to be identified twice in sequence until the current of the power distribution system returns to normal, the fault location is determined, and the fault area is isolated; The opening and isolating operation includes: at the time t corresponding to the circuit breaker to be identified for the second time a When the corresponding delay time is reached, the circuit breaker to be identified for the second time is controlled to open.

[0009] By adopting the above technical solution, a multi-level judgment method is adopted for the fault judgment 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.

[0010] In a specific implementation scheme, after determining the fault location, the method further includes: If the fault location is on the trunk line of the power distribution system and the fault location is not at the end of the trunk line of the power distribution system, the connecting circuit breaker LS is remotely closed; and power supply to the non-fault area is restored through the first substation and the second substation.

[0011] In a specific implementation scheme, the delay time difference corresponding to adjacent upstream and downstream circuit breakers in the first power distribution area is △t1; the delay time difference corresponding to adjacent upstream and downstream circuit breakers in the second power distribution area is △t2; Among them, △t1>△t2.

[0012] 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.

[0013] In a specific feasible implementation scheme, multiple circuit breakers connected to the main lines, branch lines and boundary lines of the power distribution system are all permanent magnetic circuit breakers.

[0014] In a 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 implement 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.

[0015] In a third aspect, the present application provides a computer-readable storage medium, which stores 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.

[0016] One or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages: By dividing the distribution system into a first distribution area and a 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 real-time monitoring of the actual current data of the circuit breakers in each area, 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 isolation first and then analysis is adopted, which not only improves the response speed of the system, but also will not affect the normal power supply of other areas in the event of local faults, and can achieve more accurate fault isolation, thereby improving the reliability of the distribution system and realizing efficient self-healing of the distribution system. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a structural schematic diagram of a power distribution system in an embodiment of the present application; Figure 2 It is a flow chart of a short-circuit fault self-healing control method for a power distribution system in an embodiment of the present application; Figure 3 is a schematic diagram of a case where a fault occurs in the trunk line of the first power distribution area in an embodiment of the present application; Figure 4 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; Figure 5 is a schematic diagram of a fault occurring downstream of the second power distribution area FB4 in an embodiment of the present application; Figure 6 is a schematic diagram of a fault occurring downstream of the second power distribution area FB3 in an embodiment of the present application; Figure 7 It is a schematic diagram of building a simulation environment in an embodiment of the present application. DETAILED DESCRIPTION

[0018] In order to enable technicians in this field 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.

[0019] In the description of the embodiments of the present application, words such as "for example" or "for example" are used to indicate examples, illustrations or explanations. Any embodiment or design described as "for example" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "for example" or "for example" is intended to present related concepts in a specific way.

[0020] In the description of the embodiments of the present application, the meaning of the term "multiple" refers to 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 cannot 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 "include", "comprise", "have" and their variations all mean "including but not limited to", unless otherwise specifically emphasized.

[0021] 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 a plurality of circuit breakers connected to the main line, branch line and boundary line 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 can understand that a connecting circuit breaker LS is connected between the two distribution systems; normally, the connecting circuit breaker LS is in an open state, and the corresponding distribution system is powered by the first substation. When a failure occurs in the distribution system, the second substation is also used for temporary power supply.

[0022] Preferably, the outlet circuit breaker CB1 can be selected from universal circuit breakers, plastic case circuit breakers, vacuum circuit breakers, sulfur hexafluoride circuit breakers, etc.; among them, universal circuit breakers are usually used in occasions with higher rated voltages, and plastic case circuit breakers may be slightly inferior to universal circuit breakers in rated voltage and breaking capacity, but are 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, technical personnel in this field can make comprehensive considerations based on the actual situation of the first substation, and this application does not make specific limitations on this.

[0023] 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 fast opening and closing speeds.

[0024] like Figure 2 As shown, the self-healing control method of this embodiment includes steps S1-S4.

[0025] 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; 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.

[0026] The following method can be adopted: taking the first substation as the reference point, determining the point on the distribution system trunk line that is a first preset distance away from the first substation as the distribution area division node, for example, taking the 60% and 40% division points in the entire trunk line as the division nodes; dividing the area between the outlet circuit breaker CB1 and the area division node into the first distribution area, and dividing the area downstream of the area division node into the second distribution area.

[0027] 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.

[0028] 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.

[0029] by Figure 1 Taking the system in as an example for explanation, 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.

[0030] 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.

[0031] Through the above settings, it can be seen that: for the circuit breakers in the first distribution area, the short-circuit setting currents are set differently; and the delay time interval between the two section circuit breakers is 0.1s.

[0032] Continue with Figure 1Taking the system in as an example, the second distribution area includes a third section circuit breaker FS3 located on the trunk 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.

[0033] 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 section 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.

[0034] Through the above settings, it can be seen that: for the circuit breakers in the second distribution area, the short-circuit setting currents are set to be the same; and the delay time is set in stages according to a fixed step difference of 0.05s.

[0035] In a possible implementation manner, the delay time difference corresponding to adjacent upstream and downstream circuit breakers in the first power distribution area is △t1; the delay time difference corresponding to adjacent upstream and downstream circuit breakers in the second power distribution area is △t2; Among them, △t1>△t2; for example, △t1 is 0.1s, and △t2 is 0.05s.

[0036] 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.

[0037] Since the line between the first distribution area and the first substation is shorter and 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 exit 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 exit circuit breaker CB1. Therefore, for the second distribution area, a step-by-step opening method is adopted to accurately isolate the fault location.

[0038] In particular, the specific values ​​of the set currents of the circuit breakers can be set by those skilled in the art according to the actual conditions of the lines, and this application does not make any specific limitation on this.

[0039] 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.

[0040] S4, identifying a short-circuit fault in the first distribution area based on an actual current, a short-circuit setting current and a delay time of a circuit breaker in the first distribution area, and performing a corresponding short-circuit fault isolation operation; Based on the actual current, the short-circuit setting current and the delay time of the circuit breaker in the second distribution area, the short-circuit fault of the second distribution area is identified, and the corresponding short-circuit fault isolation operation is performed.

[0041] In a possible implementation manner, after executing the corresponding short-circuit fault isolation operation in step S4, the step further includes: starting analysis based on the data of the fault location.

[0042] In a possible implementation, step S4, based on the actual current, short-circuit setting current and delay time of the circuit breaker in the first distribution area, identifies the short-circuit fault in the first distribution area and performs the corresponding short-circuit fault isolation operation, specifically including steps A1-A2.

[0043] A1: If the actual current of the circuit breaker located on the main line of 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 and the downstream adjacent circuit breaker are controlled to open to isolate the faulty area, and the connecting circuit breaker LS is remotely closed to restore power supply to the non-faulty area through the first substation and the second substation.

[0044] Combine the following Figure 3 Explain, for example Figure 3As shown, if the actual current of the first section circuit breaker FS1 exceeds the corresponding short-circuit setting current and the duration reaches the corresponding delay time, the first section circuit breaker FS1, the second section circuit breaker FS2 and the first primary branch circuit breaker FB1 are controlled to open, and the connecting circuit breaker LS is remotely closed; the fault area can be isolated, and the power supply to the non-fault area can be restored through the first substation and the second substation. In this case, the normal power supply of the downstream load of FB7 will not be affected.

[0045] A2: If the actual current of the circuit breaker located on the branch line or boundary line of 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, so as to isolate the faulty area, and restore power supply to the non-faulty area through the first substation.

[0046] Combine the following Figure 4 Explain, for example 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, then the first primary branch circuit breaker FB1 is controlled to open, so that the fault area can be isolated and the power supply to the non-fault area can be restored through the first substation. In this case, the first substation can still cover the power demand of the non-fault area of ​​the distribution system without the need to use a second substation.

[0047] 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.

[0048] In a possible implementation, step S4, based on the actual current, short-circuit setting current and delay time of the circuit breaker in the second distribution area, identifies the short-circuit fault in the second distribution area and performs the corresponding short-circuit fault isolation operation, specifically including steps B1-B2.

[0049] B1, marking the circuit breaker whose actual current in the second power distribution area exceeds the corresponding short-circuit setting current as a circuit breaker to be identified again; 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 in order from downstream to upstream, the circuit breakers to be identified are opened and isolated in sequence until the current of the power distribution system returns to normal, thereby determining the fault location and isolating the fault area; here, the current of the power distribution system returns to normal, that is, except for the circuit breaker that performs the opening and isolation operation, the actual currents of the remaining circuit breakers in the power distribution system are all lower than the corresponding short-circuit setting current, indicating that the current of the power distribution system has returned to normal; The opening and isolating operation includes: at the time t corresponding to the circuit breaker to be identified for the second time a When the corresponding delay time is reached, the circuit breaker to be identified for the second time is controlled to open.

[0050] Combine the following Figure 5 Explanation of the above process: like Figure 5 As 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, so FB6, FB4, FB3 and FS3 are all marked as circuit breakers to be identified twice; the next step is to start the opening and isolation operation 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 is opened, the actual currents of FB3 and FS3 return to below the short-circuit setting current, so it can be determined that the fault location is downstream of FB4; at this time, the isolation of the fault area is also achieved.

[0051] like Figure 6 As shown, similarly, if the fault location is downstream of FB3, then FB6, FB4, FB5, and FB3 are all disconnected to isolate the fault area, which will not be repeated here.

[0052] In a possible implementation manner, after the fault location is determined in step B2, the following steps are further included: If the fault location is on the trunk line of the power distribution system, and the fault location is not at the end of the trunk line of the power distribution system, the connecting circuit breaker LS is remotely closed; and the power supply to the non-fault area is restored through the first substation and the second substation. It can be understood that if the fault location is at the end of the trunk line of the power distribution system, it is not necessary to remotely close the connecting circuit breaker LS, and the electric energy of the second substation cannot reach the distribution system corresponding to the first substation.

[0053] Therefore, through the above steps B1-B2, a multi-level judgment method is adopted for the fault judgment 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.

[0054] Steps S1-S4, by dividing the power distribution system into a first distribution area and a second distribution area, and respectively setting the short-circuit setting current, delay time and other parameters of the circuit breakers in each area, and real-time monitoring of the actual current data of the circuit breakers in each area, the two areas are independently set, 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 isolation first and then analysis is adopted, which not only improves the response speed of the system, but also will 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.

[0055] Compared with the traditional method of first stopping the power supply of the entire line and then locating the fault based on the collected FTU information, this solution first performs accurate fault isolation and then starts FA analysis; when a line fault occurs, the power supply to the non-fault area is not interrupted, and the power supply reliability is greatly improved.

[0056] In addition, the circuit breaker in this application adopts a permanent magnetic circuit breaker, which has the characteristics of small discreteness of the opening and fast time of the whole group fault removal. The step difference of the permanent magnetic circuit breaker in the second distribution area is set to 0.05s. Figure 1 For the system, the fault clearing time of the whole group of three single-phase in-line permanent magnet circuit breakers can reach less than 25ms. As for the export circuit breaker CB1, since it is under the jurisdiction of the substation department and the distribution is complicated, its delay time can be set to 0.4s; in this way, the fault can be directly cleared by opening and closing the circuit breaker in the second distribution area, avoiding the operation of the export circuit breaker CB1.

[0057] 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 adapted to 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 areas. It can minimize the scope of fault power outages and shorten the duration of faults, and has a qualitative improvement in the self-healing solution for 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, when setting up the simulation environment, the permanent magnet fast circuit breaker is networked, all the primary side inlet and outlet terminals are connected by copper bars, and the copper bars are connected in series with impedance elements simulating the actual lines to restore the actual distribution network lines to the greatest extent. The FTUs corresponding to all circuit breakers are in the same local area network as the test equipment. 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, so as to carry out simulation tests.

[0058] 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 the 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.

[0059] 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.

[0060] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope 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 the 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, the power distribution system is divided into a first power distribution area and a second power distribution area; 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; Monitoring the actual current of the circuit breakers in the first distribution area and the actual current of the circuit breakers in the second distribution area; 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.

2. The short circuit fault self-healing control method for a power distribution system according to claim 1, characterized in that: 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, specifically including: If the actual current of the circuit breaker located on the main line of the first power distribution area exceeds the corresponding short-circuit setting current, and the actual current exceeds the corresponding short-circuit setting current for a duration that reaches 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 supply to the non-faulty area through the first substation and the second substation; 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, so as to isolate the faulty area and restore power supply to the non-faulty area through the first substation.

3. The short circuit fault self-healing control method for a power distribution system according to claim 1, characterized in that: Based on the actual current, short-circuit setting current and delay time of the circuit breaker in the second power distribution area, the short-circuit fault in the second power distribution area is identified, and the corresponding short-circuit fault isolation operation is performed, specifically including: 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; Record the time t when the actual current of the circuit breaker to be identified exceeds the corresponding short-circuit setting current a , and in order from downstream to upstream, perform the opening and isolating operation on the circuit breakers to be identified twice in sequence until the current of the power distribution system returns to normal, the fault location is determined, and the fault area is isolated; The opening and isolating operation includes: at the time t corresponding to the circuit breaker to be identified for the second time a When the corresponding delay time is reached, the circuit breaker to be identified for the second time is controlled to open.

4. The short circuit fault self-healing control method for a power distribution system 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 the fault location is not at the end of the trunk line of the power distribution system, the connecting 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 short circuit fault self-healing control method for a power distribution system according to claim 1, characterized in that: The delay time difference corresponding to the adjacent upstream and downstream circuit breakers in the first power distribution area is △t1; the delay time difference corresponding to the adjacent upstream and downstream circuit breakers in the second power distribution area is △t2; Among them, △t1>△t2.

6. The short circuit fault self-healing control method for a power distribution system 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 short circuit fault self-healing control method for a power distribution system according to claim 1, characterized in that: 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 the 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 short-circuit fault self-healing control method of the distribution system as described in any one of claims 1-7.

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.

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