A fault location method and system considering operation mode change of power distribution network

Abstract

The application discloses a fault positioning method and system considering operation mode change of a power distribution network, and relates to the technical field of power distribution network fault positioning. The method comprises the following steps: dividing the power distribution network line into a plurality of fault sections, judging and obtaining the positional relationship between each circuit breaker and each power distribution transformer; obtaining the corresponding fault occurrence section when each power distribution transformer has a power failure event in the fault section; calculating the section probability of each fault section causing at least one problem transformer to have a power failure event when a fault occurs; and determining one fault section with the maximum section probability in each fault section as a target occurrence section. The method effectively solves the problem that traditional analysis methods such as matrix calculation method are only used for fault positioning of the power distribution network with an unchanged operation mode, and the problem that when the power grid topology changes, the traditional fault analysis method is invalid and the operation and maintenance repair is passive.

Description

Technical Field

[0001] This invention relates to the field of fault location technology in power distribution networks, and more specifically, to a fault location method and system that takes into account changes in the operating mode of the power distribution network. Background Technology

[0002] The distribution network adjusts its operation mode according to load changes and maintenance needs to ensure the safe and stable operation of the power grid. Currently, the main methods for fault judgment and analysis of distribution networks include matrix calculation, probability analysis, and intelligent algorithms. However, these methods assume that the network topology of the distribution network remains unchanged. In actual operation, the topology of the distribution network changes at any time. When the operation mode of the distribution network changes, the above fault judgment and analysis methods will become ineffective, leading to errors in fault analysis and location, and resulting in a passive operation and maintenance emergency repair situation.

[0003] Therefore, at this stage, it is necessary to design a fault location method that takes into account changes in the operation mode of the distribution network in order to solve the above problems. Summary of the Invention

[0004] The purpose of this invention is to provide a fault location method and system that takes into account changes in the operation mode of the power distribution network, so as to solve the problems existing in the above-mentioned background art.

[0005] The above-mentioned technical objective of the present invention is achieved through the following technical solution:

[0006] In a first aspect, embodiments of this application provide a fault location method that takes into account changes in the operation mode of a power distribution network, comprising the following steps:

[0007] Based on the distribution of multiple circuit breakers and multiple distribution transformers in the distribution network line, the distribution network line is divided into multiple fault sections according to the preset division rules, and the circuit breakers at the first and second ends of the fault section are determined as adjacent circuit breakers. The fault section includes at least one distribution transformer.

[0008] Obtain the power transmission direction in the power distribution network line, determine and obtain the positional relationship between each circuit breaker and each distribution transformer, including downstream and non-downstream positions;

[0009] Based on the relationship between adjacent circuit breakers and their locations, the fault occurrence section is determined when each distribution transformer experiences a power outage event within the fault section.

[0010] When a fault occurs in a distribution network line, identify at least one problematic transformer among multiple distribution transformers that will experience a power outage. Based on the fault occurrence section corresponding to the power outage event of each distribution transformer, calculate the section probability that each fault section will cause at least one problematic transformer to experience a power outage event when a fault occurs. Determine the fault section with the highest section probability among all fault sections as the target occurrence section.

[0011] The beneficial effects of this invention are: by obtaining the target fault location section through the above method, it effectively solves the problem that traditional analysis methods such as matrix calculation are only applicable to fault location when the operation mode of the distribution network remains unchanged, and the problem that when the distribution network topology changes, traditional fault analysis methods become ineffective and maintenance and repair will be passive; when the operation mode of the distribution network line changes, by comparing and calculating the fault location section corresponding to the power outage event of each distribution transformer with the actual problem transformer that experienced the power outage event, the target fault location section is finally obtained.

[0012] Based on the above technical solution, the present invention can be further improved as follows.

[0013] Furthermore, the aforementioned multiple circuit breakers are represented by a first expression, which is:

[0014]

[0015] In the formula, n represents the circuit breaker number, and m represents the fault section number.

[0016] Furthermore, the above positional relationship is represented by a second expression, which is:

[0017]

[0018] In the formula, q represents the number of the distribution transformer and n represents the number of the circuit breaker.

[0019] Furthermore, the aforementioned adjacent circuit breakers include the first-end circuit breaker and the last-end circuit breaker.

[0020] Furthermore, the above methods also include:

[0021] When the value of the first expression is 0, an XOR operation is performed on the second expression to obtain a third expression used to represent the fault location segment. The third expression is:

[0022] Among them, A mi =0, A mj =0, and 0 < i ≤ n, 0 < j ≤ n;

[0023] In the formula, m represents the fault section number, q represents the distribution transformer number, i represents the first or last circuit breaker of the fault section numbered m, and j represents the last or first circuit breaker of the fault section numbered m.

[0024] Furthermore, the aforementioned problematic transformer is represented by a fourth expression, which is:

[0025] Where 0 < k ≤ q.

[0026] Furthermore, the above-mentioned segment probability is calculated using the first formula, which is:

[0027]

[0028] In the formula, P m Let m represent the segment probability of the fault segment numbered m, k represent the number of the distribution transformer that caused the power outage event, m represent the number of the fault segment, and q represent the total number of distribution transformers.

[0029] Secondly, embodiments of this application provide a fault location system that considers changes in the operation mode of a distribution network, applied to any of the fault location methods considering changes in the operation mode of a distribution network in the first aspect, including:

[0030] The segment division module is used to divide the distribution network line into multiple fault segments according to the distribution of multiple circuit breakers and multiple distribution transformers in the distribution network line and according to the preset division rules, and to determine the circuit breakers at the first and second ends of the fault segment as adjacent circuit breakers. The fault segment includes at least one distribution transformer.

[0031] The position determination module is used to obtain the power transmission direction in the power distribution network line, determine and obtain the positional relationship between each circuit breaker and each distribution transformer, including downstream and non-downstream positions.

[0032] The fault section module is used to determine the fault occurrence section in the fault section when each distribution transformer experiences a power outage event, based on the adjacent circuit breakers and their location relationships.

[0033] The segment probability module is used to identify at least one problematic transformer among multiple distribution transformers that will experience a power outage when a fault occurs in the distribution network line. Based on the fault occurrence segment corresponding to the power outage event of each distribution transformer, the module calculates the segment probability that each fault segment will cause at least one problematic transformer to experience a power outage event when a fault occurs, and determines the fault segment with the highest segment probability among all fault segments as the target occurrence segment.

[0034] Thirdly, embodiments of this application provide an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the method of any one of the first aspects.

[0035] Fourthly, embodiments of this application provide a non-transitory computer-readable storage medium that stores computer instructions that cause a computer to perform any of the methods in the first aspect.

[0036] Compared with the prior art, the present invention has at least the following beneficial effects:

[0037] It effectively solves the problem that traditional analysis methods such as matrix calculation are only applicable to fault location when the operation mode of the distribution network remains unchanged, and the problem that when the distribution network topology changes, traditional fault analysis methods become ineffective and operation and maintenance are in a passive position. When the operation mode of the distribution network line changes, by comparing and calculating the fault occurrence section corresponding to the power outage event of each distribution transformer with the actual problem transformer that the power outage event occurs, the target fault occurrence section is finally obtained. Attached Figure Description

[0038] The accompanying drawings, which are included to provide a further understanding of embodiments of the invention and form part of this application, do not constitute a limitation thereof. In the drawings:

[0039] Figure 1 This is a schematic diagram of the power distribution network lines in an embodiment of the present invention;

[0040] Figure 2 This is a flowchart of the fault location method in an embodiment of the present invention;

[0041] Figure 3 This is a connection block diagram of the fault location system in an embodiment of the present invention;

[0042] Figure 4 This is a schematic diagram of the connection of an electronic device in an embodiment of the present invention. Detailed Implementation

[0043] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0044] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0045] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0046] In the description of the embodiments of the present invention, "multiple" means at least two.

[0047] Example 1

[0048] This application provides a fault location method that takes into account changes in the operation mode of a distribution network, including the following steps:

[0049] S1. Based on the distribution of multiple circuit breakers and multiple distribution transformers in the distribution network line, the distribution network line is divided into multiple fault sections according to the preset division rules, and the circuit breakers at the first and second ends of the fault section are determined as adjacent circuit breakers. The fault section includes at least one distribution transformer.

[0050] Based on the topology of the distribution network lines (power transmission direction) and considering changes in operating mode, since the distribution network lines can be divided into different segments and branches by several sectionalizing switches, tie switches, and branch switches, and the load of the lines can be transferred to other lines through the opening and closing operations of tie switches, multiple fault sections can be obtained by dividing the network with switches as boundaries. For the adjacent circuit breaker at the beginning and end of each fault section, it can be represented as "0", and other circuit breakers corresponding to the fault section are represented as "1".

[0051] Optionally, the aforementioned multiple circuit breakers are represented by a first expression, which is:

[0052]

[0053] In the formula, n represents the circuit breaker number, and m represents the fault section number.

[0054] In this case, for the fault section numbered m, the first and last two circuit breakers of the fault section are marked as "0", and the remaining circuit breakers are marked as "1". The line area between the first and second adjacent circuit breakers is the fault section. Specifically, for example, a schematic diagram of a distribution network line is shown below. Figure 1 The structure shown is described in the following document. Figure 1 ,exist Figure 1In this table, STA represents a substation, S represents a circuit breaker (switch), HW represents a ring main unit (or branch box, etc.), and PB represents a distribution transformer. There are two substations, 17 circuit breakers, and 32 distribution transformers. When dividing fault sections, the division can be done according to Table 1.

[0055] Table 1

[0056] Q1 0 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Q2 1 0 1 1 0 1 1 1 1 1 1 1 1 1 1 1 1 Q3 1 1 0 1 1 1 1 1 1 1 1 0 1 1 1 1 1 Q4 1 1 1 0 1 1 1 1 1 1 1 0 1 1 1 1 1 Q5 1 1 1 1 0 0 1 1 1 1 1 1 1 1 1 1 1 Q6 1 1 1 1 1 0 0 1 1 1 1 1 1 1 1 1 1 Q7 1 1 1 1 1 1 0 1 1 1 1 1 0 1 1 1 1 Q8 1 1 1 1 1 1 1 0 1 1 1 1 0 1 0 1 1 Q9 1 1 1 1 1 1 1 1 0 1 1 0 1 1 1 1 1 Q10 1 1 1 1 1 1 1 1 1 0 1 0 1 1 1 1 1 Q11 1 1 1 1 1 1 1 1 1 1 0 0 1 1 1 1 1 Q12 1 1 1 1 1 1 1 1 1 1 1 1 0 1 0 1 1 Q13 1 1 1 1 1 1 1 1 1 1 1 0 1 0 1 1 1 Q14 1 1 1 1 1 1 1 1 1 1 1 1 1 0 0 1 1 Q15 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 0 Q16 1 1 1 1 1 1 1 1 1 1 1 0 1 1 1 1 0

[0057] Among them, can Figure 1 The distribution network shown is divided into 16 zones. In Table 1, Q1-Q16 represent the 16 fault sections. Each row in the table indicates the relationship between each circuit breaker and that fault section. For example, in fault section Q1, the two adjacent circuit breakers at the beginning and end of the fault section are S1 and S2. (See [reference]). Figure 1 In fault section Q2, the two adjacent circuit breakers at the beginning and end of the fault section are S2 and S5.

[0058] S2, obtain the power transmission direction in the distribution network line, determine and obtain the positional relationship between each circuit breaker and each distribution transformer, including downstream position and non-downstream position.

[0059] Based on the power transmission direction in the distribution network lines, the upstream and downstream relationships between each circuit breaker and each distribution transformer can be obtained. (See [reference]) Figure 1 ,when Figure 1 When power is transmitted from substation STA1 to various distribution transformers, distribution transformer PB1 is located upstream of circuit breaker S2. Figure 1 When power is transmitted from substation STA2 to various distribution transformers, distribution transformer PB1 is downstream of circuit breaker S2. When a fault occurs downstream of the circuit breaker, such as a short circuit or leakage, the circuit breaker will trip, and the distribution transformer downstream of the circuit breaker will lose power. By combining this upstream and downstream relationship and the power outage situation with the adjacent circuit breakers in the fault section, it is possible to analyze the fault section that caused the power outage of a certain distribution transformer.

[0060] Optionally, the above positional relationship is represented by a second expression, which is:

[0061]

[0062] In the formula, q represents the number of the distribution transformer and n represents the number of the circuit breaker.

[0063] Specifically, according to the passage Figure 1Substation STA1 supplies electrical energy to each distribution transformer. The positional relationship between the distribution transformer and the circuit breaker can be represented by Table 2.

[0064] Table 2

[0065]

[0066]

[0067] In this context, distribution transformer PB1 is downstream of circuit breaker S1, and is represented by "1". Similarly, distribution transformers PB2, PB3, PB4, and PB5 are downstream of circuit breaker S2. The downstream position indicates that the distribution transformer belongs to a certain circuit breaker for control. Since distribution transformer PB1 is downstream of circuit breaker S1, it is controlled by circuit breaker S1. Since distribution transformers PB2, PB3, PB4, and PB5 are downstream of circuit breaker S2, they are controlled by circuit breaker S2.

[0068] S3, based on the adjacent circuit breakers and their location relationships, obtain the fault occurrence section corresponding to the power outage event of each distribution transformer in the fault section.

[0069] Optionally, the aforementioned adjacent circuit breakers include a start-end circuit breaker and a finish-end circuit breaker.

[0070] Optionally, the above methods also include:

[0071] When the value of the first expression is 0, an XOR operation is performed on the second expression to obtain a third expression used to represent the fault location segment. The third expression is:

[0072] Among them, A mi =0, A mj =0, and 0 < i ≤ n, 0 < j ≤ n;

[0073] In the formula, m represents the fault section number, q represents the distribution transformer number, i represents the first or last circuit breaker of the fault section numbered m, and j represents the last or first circuit breaker of the fault section numbered m.

[0074] Taking the value of the first expression as 0 and performing an XOR operation on the second expression yields the results shown in Table 3.

[0075] Table 3

[0076]

[0077]

[0078] Specifically, when a power outage occurs in distribution transformer PB1, it indicates that the faulty section is Q1. When a power outage occurs in distribution transformer PB2, it indicates that the faulty sections are Q2 and Q3. The same applies to distribution transformers PB1 through PB32.

[0079] S4. Obtain at least one problematic transformer among multiple distribution transformers that experiences a power outage when a fault occurs in the distribution network line. Based on the fault occurrence section corresponding to the power outage event of each distribution transformer, calculate the section probability that each fault section will cause at least one problematic transformer to experience a power outage event when a fault occurs. Determine the fault section with the highest section probability among all fault sections as the target occurrence section.

[0080] Optionally, the aforementioned transformer problem is represented by a fourth expression, which is:

[0081] Where 0 < k ≤ q.

[0082] Optionally, the above segment probability is calculated using the first formula, which is:

[0083]

[0084] In the formula, P m Let m represent the segment probability of the fault segment numbered m, k represent the number of the distribution transformer that caused the power outage event, m represent the number of the fault segment, and q represent the total number of distribution transformers.

[0085] Among them, such as Figure 1 The diagram shows the power distribution network lines. If the received power outage event is:

[0086] D m = [0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 ]; There are a total of 32 bits in the formula, which correspond to distribution transformers PB1-PB32 respectively. If the 14th to 17th bits are 1, it means that a power outage event has occurred in distribution transformers PB14-PB17.

[0087] Specifically, the probability of each faulty section causing a power outage event between distribution transformers PB14 and PB17 can be calculated using the first formula. The results are shown in Table 4.

[0088] Table 4

[0089]

[0090]

[0091] Among the power outages that caused the power distribution transformers PB14 and PB17, the fault section with the highest probability of failure is Q9. Therefore, it is assumed that fault section Q9 has failed, and an investigation is carried out to locate the fault. Secondly, the fault section Q8 has the next lowest probability of failure, so it can be considered a suspected fault section.

[0092] Example 2

[0093] This application provides a fault location system that considers changes in distribution network operation modes, applicable to any of the fault location methods in Embodiment 1 that consider changes in distribution network operation modes. See also... Figure 3 ,include:

[0094] The segment division module is used to divide the distribution network line into multiple fault segments according to the distribution of multiple circuit breakers and multiple distribution transformers in the distribution network line and according to the preset division rules, and to determine the circuit breakers at the first and second ends of the fault segment as adjacent circuit breakers. The fault segment includes at least one distribution transformer.

[0095] The position determination module is used to obtain the power transmission direction in the power distribution network line, determine and obtain the positional relationship between each circuit breaker and each distribution transformer, including downstream and non-downstream positions.

[0096] The fault section module is used to determine the fault occurrence section in the fault section when each distribution transformer experiences a power outage event, based on the adjacent circuit breakers and their location relationships.

[0097] The segment probability module is used to identify at least one problematic transformer among multiple distribution transformers that will experience a power outage when a fault occurs in the distribution network line. Based on the fault occurrence segment corresponding to the power outage event of each distribution transformer, the module calculates the segment probability that each fault segment will cause at least one problematic transformer to experience a power outage event when a fault occurs, and determines the fault segment with the highest segment probability among all fault segments as the target occurrence segment.

[0098] Example 3

[0099] This application provides an electronic device, such as... Figure 4 As shown, it includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the method of any one of Embodiment 1.

[0100] Example 4

[0101] This application provides a non-transitory computer-readable storage medium that stores computer instructions that cause a computer to perform any of the methods in Embodiment 1.

[0102] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A fault location method considering changes in the operation mode of a distribution network, characterized in that, Includes the following steps: Based on the distribution of multiple circuit breakers and multiple distribution transformers in the distribution network line, the distribution network line is divided into multiple fault sections according to the preset division rules, and the circuit breakers at the beginning and end of the fault section are determined as adjacent circuit breakers. The fault section includes at least one distribution transformer. The power transmission direction in the power distribution network line is obtained, and the positional relationship between each circuit breaker and each distribution transformer is determined and obtained. The positional relationship includes downstream position and non-downstream position. Based on the adjacent circuit breakers and their positional relationships, the fault occurrence section corresponding to the power outage event of each of the distribution transformers in the fault section is obtained; the adjacent circuit breakers include the first-end circuit breaker and the last-end circuit breaker; When a fault occurs in the power distribution network line, at least one problematic transformer among multiple distribution transformers will experience a power outage. Based on the fault occurrence section corresponding to the power outage event of each distribution transformer, calculate the section probability that each fault section will cause at least one problematic transformer to experience a power outage event when a fault occurs. Determine the fault section with the highest section probability among all the fault sections as the target occurrence section. The plurality of circuit breakers are represented by a first expression, which is: ； In the formula, n represents the circuit breaker number, and m represents the fault section number; The positional relationship is represented by a second expression, which is: ； In the formula, q represents the number of the distribution transformer and n represents the number of the circuit breaker; The method further includes: when the value of the first expression is 0, performing an XOR operation on the second expression to obtain a third expression representing the fault occurrence segment, wherein the third expression is: ； In the formula, m represents the fault section number, q represents the distribution transformer number, i represents the starting or ending circuit breaker of the fault section numbered m, and j represents the ending or starting circuit breaker of the fault section numbered m; the problematic transformer is represented by the fourth expression, which is: ； The segment probability is calculated using a first formula, which is: ； In the formula, Let m represent the segment probability of the fault segment numbered m, k represent the number of the distribution transformer that caused the power outage event, m represent the number of the fault segment, and q represent the total number of distribution transformers.

2. A fault location system that considers changes in the operation mode of a distribution network, applied to the fault location method that considers changes in the operation mode of a distribution network as described in claim 1, characterized in that, include: The segment division module is used to divide the distribution network line into multiple fault segments according to the distribution of multiple circuit breakers and multiple distribution transformers in the distribution network line and according to the preset division rules, and to determine the circuit breakers at the beginning and end of the fault segment as adjacent circuit breakers. The fault segment includes at least one distribution transformer. The position determination module is used to obtain the power transmission direction in the power distribution network line, determine and obtain the positional relationship between each circuit breaker and each distribution transformer, the positional relationship including downstream position and non-downstream position; The fault section module is used to determine the fault occurrence section in the fault section when each of the distribution transformers experiences a power outage event, based on the adjacent circuit breakers and their positional relationship. The segment probability module is used to obtain at least one problematic transformer among multiple distribution transformers that will experience a power outage when a fault occurs in the distribution network line. Based on the fault occurrence segment corresponding to the power outage event of each distribution transformer, the module calculates the segment probability that each fault segment will cause at least one of the problematic transformers to experience a power outage event when a fault occurs, and determines the fault segment with the highest segment probability among all the fault segments as the target occurrence segment.

3. An electronic device, characterized in that, It includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the method of claim 1.

4. A non-transitory computer-readable storage medium, characterized in that, The non-transitory computer-readable storage medium stores computer instructions that cause the computer to perform the method described in claim 1.

Images