A power distribution network fault detection method and system based on voltage telemetry values

Abstract

The application discloses a power distribution network fault detection method and system based on voltage telemetry values, and comprises the following steps: synthesizing zero sequence voltage through power distribution network bus voltage telemetry values, constructing a fault starting criterion, and according to the three-phase voltage rise and drop, identifying the fault type in layers, further constructing the phase difference of zero sequence voltage and phase voltage from three-phase voltage, combining the line power change, identifying different types of faults with similar fault characteristics (such as ferroresonance, broken line, single-phase grounding, TV primary and secondary fuse blowing), which can effectively avoid the misjudgment of the power distribution network fault type caused by the insufficient ability and experience of the on-duty dispatcher and the incomplete collection of fault information, and improve the fault handling efficiency of the power distribution network.

Description

Technical Field

[0001] This invention relates to the field of power distribution network fault detection technology, and specifically to a power distribution network fault detection method and system based on voltage telemetry values. Background Technology

[0002] my country's 10kV to 35kV distribution network is a low-current grounding system. When the system experiences grounding or three-phase load imbalance due to faults such as insulation damage or conductor breakage, the neutral point potential shifts, causing abnormal bus voltage. On-duty dispatchers need to accurately determine the specific fault type based on bus voltage changes to facilitate subsequent handling. However, the traditional method of relying on manual judgment places high demands on the dispatcher's skills, and since some distribution network faults share similar characteristics, misjudgments are often prone to occur due to insufficient experience or incomplete fault information collection. Summary of the Invention

[0003] The technical problem to be solved by this invention is to provide a method and system for detecting distribution network faults based on voltage telemetry values, in response to the above-mentioned problems in the prior art. This invention aims to achieve early warning of distribution network faults and accurate identification of fault types, and avoid misjudgment of distribution network fault types and delay in handling distribution network faults due to the lack of skill of duty dispatchers and incomplete collection of fault information.

[0004] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0005] A method for detecting distribution network faults based on voltage telemetry values ​​includes:

[0006] Step S101: Obtain the voltage telemetry values ​​of the distribution network, including the effective value U of the three-phase voltage of the medium-voltage side bus. A U B and U C The effective values ​​of the three line voltages U between the three phases AB U BC U CA The effective value of the zero-sequence voltage U0 is calculated based on the voltage telemetry value.

[0007] Step S102, the fault start criterion shown in the judgment formula (1) is met:

[0008]

[0009] In the above formula, K0, K1, and K2 are reliability coefficients, and E N The rated phase voltage on the medium-voltage side; if the fault initiation criterion shown in equation (1) is valid, then the distribution network is determined to have a fault.

[0010] Optionally, the functional expression for calculating the effective value U0 of the zero-sequence voltage based on the voltage telemetry value in step S101 is as follows:

[0011]

[0012] Optionally, after determining that a fault has occurred in the distribution network in step S102, the method further includes checking the effective value of the three-phase voltage U. A U B and U C When the three-phase voltage rise condition shown in equation (3) is met, it is determined that the distribution network has experienced frequency-division ferroresonance or high-frequency ferroresonance:

[0013] U A >kE N U B >kE N U C >kE N (3)

[0014] In the above formula, k is a coefficient greater than 1.

[0015] Optionally, after determining that a fault has occurred in the distribution network in step S102, the method further includes checking the effective value of the three-phase voltage U. A U B and U C When the three-phase voltage rise condition shown in equation (3) is not met, the two-phase voltage rise condition shown in equation (4), the one-two-phase voltage rise condition shown in equation (5), and the line power condition shown in equation (6) are judged. When the two-phase voltage rise condition shown in equation (4) is met, the one-two-phase voltage rise condition shown in equation (5) is met, and the line power ratio condition before and after the fault shown in equation (6) is not met, the distribution network is determined to be disconnected.

[0016] U A >kE N U B >kE N U C <k′E N

[0017] or U A >kE N U B <k′E N U C >kE N (4)

[0018] or U A <k′E N U B >kE N U C >kE N

[0019] U A >kEN U B <k′E N U C <k′E N

[0020] or U A <k′E N U B >kE N U C <k′E N (5)

[0021] or U A <k′E N U B <k′E N U C >kE N

[0022]

[0023] In the above formula, k′ is a coefficient less than 1, and P k and P fk These represent the line power before and after a fault on the k-th line in the voltage telemetry values, where k = 1, 2, 3...m, and m is the number of lines. set1 K set2 The lower and upper limits of the line power ratio before and after the fault are respectively.

[0024] Optionally, it also includes performing the phase condition judgment shown in Equation (7) when the two-phase voltage rise condition shown in Equation (4) is met, the one-two-phase voltage rise condition shown in Equation (5) is met, and the line power ratio condition before and after the fault shown in Equation (6) is met. When the phase condition shown in Equation (7) is met, it is determined that the distribution network has a fundamental frequency ferroresonance, and when the phase condition shown in Equation (7) is not met, it is determined that the distribution network has a single-phase ground fault.

[0025]

[0026]

[0027]

[0028] In the above formula, φ set The phase parameters are Δφ1 to Δφ3, which are intermediate variables, and x1 to x3 are intermediate variables.

[0029] Optionally, it also includes the effective value of the three-phase voltage U A U B and U CIf the three-phase voltage rise condition shown in Equation (3) is not met, the two-phase voltage rise condition shown in Equation (4) is not met, or the one-phase voltage rise condition shown in Equation (5) is not met, the TV primary side one-phase disconnection condition shown in Equation (8) is judged. If the primary side one-phase disconnection condition shown in Equation (8) is met, the TV primary side one-phase disconnection condition of the distribution network is determined to be true.

[0030] k1E N A <k2E N k3E N B <k4E N k3E N C <k4E N ,

[0031] or k3E N A <k4E N ,k1E N B <k2E N k3E N C <k4E N (8)

[0032] or k3E N A <k4E N k3E N B <k4E N k1E N C <k2E N

[0033] In the above formula, k1 to k4 are parameters.

[0034] Optionally, after performing the TV primary side phase disconnection condition judgment as shown in Equation (8), it further includes performing the TV secondary side phase disconnection condition judgment as shown in Equation (9) when the primary side phase disconnection condition shown in Equation (8) is not met. If the TV secondary side phase disconnection condition shown in Equation (9) is met, it is determined that the TV secondary side phase disconnection of the distribution network is broken.

[0035] U A <k5E N k3E N B <k4E N k3E N C <k4E N ,

[0036] ​​​​​​​​​​​or k3E N A <k4E N U B <k5E N k3E N C <k4E N (9)

[0037] or k3E N A <k4E N k3E N B <k4E N U C <k5E N

[0038] In the above formula, k5 is a parameter.

[0039] Optionally, after performing the TV secondary side one-phase disconnection condition judgment as shown in equation (9), the method further includes performing the TV primary side two-phase disconnection condition judgment as shown in equation (10) and the TV secondary side two-phase disconnection condition judgment as shown in equation (11) when the TV secondary side one-phase disconnection condition judgment as shown in equation (9) is not met:

[0040] k1E N A <k2E N k1E N B <k2E N k3E N C <k4E N ,

[0041] or k3E N A <k4E N k1E N B <k2E N k1E N C <k2E N (10)

[0042] or k1E N A <k2E N k3E N B <k4E N k1E N C <k2E N ​​​​​​​​​​​​​

[0043] U A <k5E N U B <k5E N k3E N C <k4E N ,

[0044] or k3E N A <k4E N U B <k5E N U C <k5E N (11)

[0045] or U A <k5E N k3E N B <k4E N U C <k5E N

[0046] If the two-phase disconnection condition of the TV primary side shown in equation (10) is met, then the two-phase disconnection condition of the TV primary side of the distribution network is determined to be true. If the two-phase disconnection condition of the TV secondary side shown in equation (11) is met, then the two-phase disconnection condition of the TV secondary side of the distribution network is determined to be true.

[0047] In addition, the present invention provides a distribution network fault detection system based on voltage telemetry values, including a microprocessor and a memory interconnected thereto, wherein the microprocessor is programmed or configured to execute the distribution network fault detection method based on voltage telemetry values.

[0048] Furthermore, the present invention also provides a computer-readable storage medium storing a computer program for being programmed or configured by a microprocessor to execute the distribution network fault detection method based on voltage telemetry values.

[0049] ​​​Compared with existing technologies, this invention has the following main advantages: Distribution network fault types are complex and diverse, and some fault characteristics are quite similar. To address the difficulties in manually judging and identifying typical distribution network faults (single-phase grounding, open circuit, resonance, TV primary and secondary fuse blowouts, etc.), this invention proposes a method for identifying distribution network fault types based on remote sensing values ​​of bus voltage. Considering that accurate identification of distribution network fault types depends on zero-sequence voltage, and to solve the problem that zero-sequence voltage is not collected and uploaded in the dispatch automation master station system, leading to the inability to achieve fault early warning and accurate fault type identification, this invention proposes a method for distribution network fault detection based on voltage remote sensing values. This method uses the effective values ​​of the three-phase bus voltage to synthesize zero-sequence voltage, which, together with other remote sensing values ​​in the master station system, constitutes the fault initiation criterion and fault type judgment condition. This enables distribution network fault early warning and accurate fault type identification, effectively avoiding misjudgment of distribution network fault types and delays in handling distribution network faults due to insufficient skill of the on-duty dispatcher and incomplete fault information collection. Attached Figure Description

[0050] Figure 1 This is a flowchart illustrating the method of an embodiment of the present invention.

[0051] Figure 2 This is a power distribution network fault model in an embodiment of the present invention.

[0052] Figure 3 The effective value of the three-phase bus voltage in the embodiment of the present invention.

[0053] Figure 4 The effective values ​​of the three line voltages of the bus in this embodiment of the invention.

[0054] Figure 5 This is the power curve of feeder L1 before and after the fault in an embodiment of the present invention.

[0055] Figure 6 This is the power curve of feeder L2 before and after the fault in an embodiment of the present invention.

[0056] Figure 7 This is the power curve of feeder L3 before and after the fault in an embodiment of the present invention.

[0057] Figure 8 This is the power curve of feeder L4 before and after the fault in an embodiment of the present invention.

[0058] Figure 9 This is the power curve of feeder L5 before and after the fault in an embodiment of the present invention. Detailed Implementation

[0059] See Figure 1 The distribution network fault detection method based on voltage telemetry values ​​in this embodiment includes:

[0060] Step S101: Obtain the voltage telemetry values ​​of the distribution network, including the effective value U of the three-phase voltage of the medium-voltage side bus. A U B and U C The effective values ​​of the three line voltages U between the three phases AB U BC U CA The effective value of the zero-sequence voltage U0 is calculated based on the voltage telemetry value.

[0061] Step S102, the fault start criterion shown in the judgment formula (1) is met:

[0062]

[0063] In the above formula, K0, K1, and K2 are reliability coefficients, and E N The rated phase voltage on the medium-voltage side; if the fault initiation criterion shown in equation (1) is met, then the distribution network is determined to have a fault. In this embodiment, the reliability coefficients K0, K1, and K2 are 0.15, 0.98, and 1.02, respectively. In actual applications, they can be adjusted according to the specific distribution network structure.

[0064] In this embodiment, the effective value U of the three-phase voltage of the medium-voltage side (10kV) bus is continuously collected in the power distribution system. A U B U C The effective values ​​of the three line voltages U between the three phases AB U BC U CA and line output power P k (k = 1, 2, 3...m, where m is the number of lines), and the effective value of the zero-sequence voltage U0 is calculated from the effective value of the three-phase voltage. The functional expression for calculating the effective value of the zero-sequence voltage U0 based on the voltage telemetry value in step S101 is as follows:

[0065]

[0066] In the above formula, E N This is the rated phase voltage on the medium-voltage side.

[0067] See Figure 1 In this embodiment, after determining that a fault has occurred in the distribution network in step S102, the method further includes checking the effective value of the three-phase voltage U. A U B and U C When the three-phase voltage rise condition shown in equation (3) is met, it is determined that the distribution network has experienced frequency-division ferroresonance or high-frequency ferroresonance:

[0068] U A >kE N U B >kE NU C >kE N (3)

[0069] In the above formula, k is a coefficient greater than 1. In this embodiment, the coefficient k is taken as 1.05, but it can be adjusted according to the specific distribution network structure in actual applications.

[0070] See Figure 1 In this embodiment, after determining that a fault has occurred in the distribution network in step S102, the method further includes checking the effective value of the three-phase voltage U. A U B and U C When the three-phase voltage rise condition shown in equation (3) is not met, the two-phase voltage rise condition shown in equation (4), the one-two-phase voltage rise condition shown in equation (5), and the line power condition shown in equation (6) are judged. When the two-phase voltage rise condition shown in equation (4) is met, the one-two-phase voltage rise condition shown in equation (5) is met, and the line power ratio condition before and after the fault shown in equation (6) is not met, the distribution network is determined to be disconnected.

[0071] U A >kE N U B >kE N U C <k′E N

[0072] or U A >kE N U B <k′E N U C >kE N (4)

[0073] or U A <k′E N U B >kE N U C >kE N

[0074] U A >kE N U B <k′E N U C <k′E N

[0075] or U A <k′E N U B >kE N U C <k′E N (5)

[0076] or U A <k′E N U B <k′E N U C >kE N

[0077]

[0078] In the above formula, k′ is a coefficient less than 1, and P k and P fk These represent the line power before and after a fault on the k-th line in the voltage telemetry values, where k = 1, 2, 3...m, and m is the number of lines. set1 K set2 The lower and upper limits of the line power ratio before and after the fault are given respectively. In this embodiment, the coefficient k′ is taken as 0.95, but it can be adjusted according to the specific distribution network structure in actual applications. K set1 K set2 The values ​​are set to 0.65 and 1.35 respectively, and can be adjusted according to the specific distribution network structure in practical applications.

[0079] See Figure 1 This embodiment also includes performing the phase condition judgment shown in Equation (7) when the two-phase voltage rise condition shown in Equation (4) is met, the one-two-phase voltage rise condition shown in Equation (5) is met, and the line power ratio condition before and after the fault shown in Equation (6) is met. When the phase condition shown in Equation (7) is met, it is determined that the distribution network has a fundamental frequency ferroresonance. When the phase condition shown in Equation (7) is not met, it is determined that the distribution network has a single-phase ground fault.

[0080]

[0081]

[0082]

[0083] In the above formula, φ set Let φ be the phase parameter, Δφ1~Δφ3 be intermediate variables, and x1~x3 be intermediate variables. Phase parameter φ set 3° or 5° can be selected, and the angle can be adjusted according to the specific distribution network structure in practical applications.

[0084] See Figure 1 This embodiment also includes the effective value of the three-phase voltage U A U B and U CIf the three-phase voltage rise condition shown in Equation (3) is not met, the two-phase voltage rise condition shown in Equation (4) is not met, or the one-phase voltage rise condition shown in Equation (5) is not met, the TV primary side one-phase disconnection condition shown in Equation (8) is judged. If the primary side one-phase disconnection condition shown in Equation (8) is met, the TV primary side one-phase disconnection condition of the distribution network is determined to be true.

[0085] k1E N A <k2E N k3E N B <k4E N k3E N C <k4E N ,

[0086] or k3E N A <k4E N k1E N B <k2E N k3E N C <k4E N (8)

[0087] or k3E N A <k4E N k3E N B <k4E N k1E N C <k2E N

[0088] In the above formula, k1 to k4 are parameters. k1 and k2 can be taken as 0.15 and 0.85 respectively, and k3 and k4 can be taken as 0.95 and 1.05 respectively. In practical applications, they can be adjusted according to the specific distribution network structure.

[0089] See Figure 1 In this embodiment, after judging the TV primary side phase disconnection condition shown in formula (8), it also includes judging the TV secondary side phase disconnection condition shown in formula (9) when the primary side phase disconnection condition shown in formula (8) is not met. If the TV secondary side phase disconnection condition shown in formula (9) is met, it is determined that the TV secondary side phase disconnection of the distribution network is broken.

[0090] U A <k5E N k3E N B <k4E N k3E​​​​​​​​​​N C <k4E N ,

[0091] or k3E N A <k4E N U B <k5E N k3E N C <k4E N (9)

[0092] or k3E N A <k4E N k3E N B <k4E N U C <k5E N

[0093] In the above formula, k5 is a parameter. k5 can be taken as 0.1, and can be adjusted according to the specific distribution network structure in practical applications.

[0094] See Figure 1 In this embodiment, after determining the one-phase disconnection condition of the TV secondary side as shown in equation (9), it also includes determining the two-phase disconnection condition of the TV primary side as shown in equation (10) and the two-phase disconnection condition of the TV secondary side as shown in equation (11) when the determination of the one-phase disconnection condition of the TV secondary side as shown in equation (9) is not met.

[0095] k1E N A <k2E N k1E N B <k2E N k3E N C <k4E N ,

[0096] or k3E N A <k4E N k1E N B <k2E N k1E N C <k2E N (10)

[0097] or k1E N A <k2E N k3E​​​​​​​​​​​​N B <k4E N k1E N C <k2E N

[0098] U A <k5E N U B <k5E N k3E N C <k4E N ,

[0099] or k3E N A <k4E N U B <k5E N U C <k5E N (11)

[0100] or U A <k5E N k3E N B <k4E N U C <k5E N

[0101] If the two-phase disconnection condition of the TV primary side shown in equation (10) is met, then the two-phase disconnection condition of the TV primary side of the distribution network is determined to be true. If the two-phase disconnection condition of the TV secondary side shown in equation (11) is met, then the two-phase disconnection condition of the TV secondary side of the distribution network is determined to be true.

[0102] The specific distribution network fault model addressed in this embodiment is as follows: Figure 2 As shown, the distribution network busbar is connected to five feeders (feeders L1 to L5), among which feeder L4 experienced a single-phase ground fault. The effective value of the three-phase voltage U... A U B U C The effective values ​​of the three line voltages U between the three phases AB U BC U CA See attached for details. Figure 3 and 4 As shown in the attached figure, the effective values ​​of the three phase voltages are 2369.20V, 8709.79V, and 7671.59V, respectively, and the effective values ​​of the three line voltages are 10002.96V, 10002.95V, and 10002.58V, respectively. The effective value of the zero-sequence voltage of the busbar calculated by formula (2) is 3666.4V = 0.635E. N From the line voltage formula:​​​​​

[0103]

[0104] The line voltage can be calculated to be 5775.1V = 1.0003E. N Obviously, the fault initiation criterion shown in equation (1) is valid. With the initiation criterion valid, a fault is determined to have occurred in the system. Simultaneously, the simulated power waveforms of each line (feeder L1 to feeder L5) before and after the fault are as follows: Figures 5-9 As shown, the power results of the five lines before and after the fault are 938.19kW, 1819.75kW, 949.84kW, 926.73kW, 945.00kW and 1073.86kW, 2079.97kW, 1091.28kW, 1093.90kW, 1064.96kW, respectively. The calculated power ratios before and after the fault are 0.8737, 0.8749, 0.8704, 0.8472, and 0.8874, respectively, which obviously satisfy the conditions of formula (6). In addition, U A =0.4104E N U B =1.5068E N U C =1.3288E N Obviously, formula (4) holds true. Calculated from formula (7), Δφ1~Δφ3 are 13.42°, -46.58°, and 73.42° respectively, which do not meet the conditions of formula (7). Therefore, the fault type can be determined to be a single-phase ground fault, and the judgment result is correct.

[0105] In summary, this embodiment discloses a method for identifying distribution network fault types based on voltage telemetry values. By synthesizing zero-sequence voltage from distribution network bus voltage telemetry values, a fault initiation criterion is constructed. Based on the rise and fall of three-phase voltages, fault types are identified hierarchically. Furthermore, the phase difference between the zero-sequence voltage and phase voltages is constructed from the three-phase voltages. Combined with changes in line power, different types of faults with similar fault characteristics (such as ferroresonance, open circuit, single-phase grounding, and TV primary and secondary fuse blowouts) are identified. This method effectively avoids misjudgments of distribution network fault types due to insufficient ability and experience of on-duty dispatchers and incomplete fault information collection, thereby improving the efficiency of distribution network fault handling.

[0106] Furthermore, this embodiment also provides a distribution network fault detection system based on voltage telemetry values, including a microprocessor and a memory interconnected thereto. The microprocessor is programmed or configured to execute the distribution network fault detection method based on voltage telemetry values. This embodiment also provides a computer-readable storage medium storing a computer program for being programmed or configured by the microprocessor to execute the distribution network fault detection method based on voltage telemetry values.

[0107] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-readable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code. This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create a machine for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process. Figure 1 One or more processes and / or boxes Figure 1 The functions specified in one or more boxes. These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable apparatus for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0108] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A method for detecting distribution network faults based on voltage telemetry values, characterized in that, include: Step S101: Obtain the voltage telemetry values ​​of the distribution network, including the effective values ​​of the three-phase voltages of the medium-voltage side bus. U A , U B and U C The effective values ​​of the three line voltages between the three phases U AB , U BC , U CA The effective value of the zero-sequence voltage is calculated based on the voltage telemetry value. U 0; Step S102, the fault start criterion shown in the judgment formula (1) is met: ，（1） In the above formula, K 0 、K 1 、K 2 is the reliability coefficient. E N The rated phase voltage on the medium-voltage side; if the fault initiation criterion shown in equation (1) is valid, then the distribution network is determined to have a fault; After determining that a fault has occurred in the distribution network in step S102, the method also includes checking the effective value of the three-phase voltage. U A , U B and U C When the three-phase voltage rise condition shown in equation (3) is met, it is determined that the distribution network has experienced frequency-division ferroresonance or high-frequency ferroresonance: ，（3） In the above formula, k A coefficient greater than 1; After determining that a fault has occurred in the distribution network in step S102, the method also includes checking the effective value of the three-phase voltage. U A , U B and U C When the three-phase voltage rise condition shown in equation (3) is not met, the two-phase voltage rise condition shown in equation (4), the one-two-phase voltage rise condition shown in equation (5), and the line power condition shown in equation (6) are judged. When the two-phase voltage rise condition shown in equation (4) is met, the one-two-phase voltage rise condition shown in equation (5) is met, and the line power ratio condition before and after the fault shown in equation (6) is not met, the distribution network is determined to be a fault. ，（4） ，（5） ，（6） In the above formula, For coefficients less than 1, and These represent the line power before and after the fault on the k-th line in the voltage telemetry values. k =1,2,3...m, where m is the number of lines. K set1 , K set2 The lower and upper limits of the line power ratio before and after the fault, respectively; It also includes performing the phase condition judgment shown in Equation (7) when the two-phase voltage rise condition shown in Equation (4) is met, the one-two-phase voltage rise condition shown in Equation (5) is met, and the line power ratio condition before and after the fault shown in Equation (6) is met. When the phase condition shown in Equation (7) is met, it is determined that the distribution network has a fundamental frequency ferroresonance, and when the phase condition shown in Equation (7) is not met, it is determined that the distribution network has a single-phase ground fault. ，（7） ， ， ， ， ， ， In the above formula, For phase parameters, ~ As an intermediate variable, ~ It is an intermediate variable.

2. The distribution network fault detection method based on voltage telemetry values ​​according to claim 1, characterized in that, In step S101, the effective value of the zero-sequence voltage is calculated based on the voltage telemetry value. U The function expression for 0 is: ，（2）。 3. The distribution network fault detection method based on voltage telemetry values ​​according to claim 1, characterized in that, This also includes the effective value of three-phase voltage. U A , U B and U C If the three-phase voltage rise condition shown in Equation (3) is not met, the two-phase voltage rise condition shown in Equation (4) is not met, or the two-phase voltage rise condition shown in Equation (5) is not met, the TV primary side one-phase disconnection condition shown in Equation (8) is judged. If the primary side one-phase disconnection condition shown in Equation (8) is met, the TV primary side one-phase disconnection condition of the distribution network is judged. （8） In the above formula, ~ For parameters.

4. The distribution network fault detection method based on voltage telemetry values ​​according to claim 3, characterized in that, After the TV primary side phase disconnection condition judgment shown in Equation (8) is performed, the TV secondary side phase disconnection condition judgment shown in Equation (9) is also performed when the primary side phase disconnection condition shown in Equation (8) is not met. If the TV secondary side phase disconnection condition shown in Equation (9) is met, the TV secondary side phase disconnection of the distribution network is determined to be a disconnection. （9） In the above formula, For parameters.

5. The distribution network fault detection method based on voltage telemetry values ​​according to claim 4, characterized in that, After performing the TV secondary side one-phase disconnection condition judgment as shown in equation (9), the method further includes performing the TV primary side two-phase disconnection condition judgment as shown in equation (10) and the TV secondary side two-phase disconnection condition judgment as shown in equation (11) when the TV secondary side one-phase disconnection condition judgment as shown in equation (9) is not met: （10） （11） If the two-phase disconnection condition of the TV primary side shown in equation (10) is met, then the two-phase disconnection condition of the TV primary side of the distribution network is determined to be true. If the two-phase disconnection condition of the TV secondary side shown in equation (11) is met, then the two-phase disconnection condition of the TV secondary side of the distribution network is determined to be true.

6. A distribution network fault detection system based on voltage telemetry values, comprising a microprocessor and a memory interconnected, characterized in that, The microprocessor is programmed or configured to execute the distribution network fault detection method based on voltage telemetry values ​​as described in any one of claims 1 to 5.

7. A computer-readable storage medium storing a computer program, characterized in that, The computer program is used to be programmed or configured by a microprocessor to execute the distribution network fault detection method based on voltage telemetry values ​​as described in any one of claims 1 to 5.

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