Distribution cable intermediate head health assessment method, device, equipment and medium

Abstract

The invention relates to a power distribution cable intermediate head health assessment method, device and equipment and a medium, and the method comprises the steps: carrying out the periodic data collection of a to-be-assessed power distribution cable intermediate head through a ground electric wave partial discharge sensor; calculating the average growth rate of the average value of the partial discharge quantity, the average growth rate of the maximum value of the partial discharge quantity and the average growth rate of the average discharge frequency of the cyclic wave in the evaluation period; establishing a hierarchical structure model according to an analytic hierarchy process; constructing a judgment matrix according to the relationship among the factors in the hierarchical structure model, obtaining the weight of each factor through a root method, and determining the evaluation value score of each factor; and calculating a comprehensive score value of health assessment of the distribution cable intermediate head according to the weight of each factor and the assessment value score of each factor, and determining the health state of the distribution cable intermediate head according to the comprehensive score value of health assessment of the distribution cable intermediate head. According to the invention, the health state of the distribution cable intermediate head can be comprehensively and accurately determined.

Description

Technical Field

[0001] The present invention relates to the technical field of partial discharge monitoring and early warning for distribution cables in a distribution network, and in particular to a method, device, equipment and medium for health assessment of an intermediate head of a distribution cable. Background Art

[0002] Distribution cables are key equipment in distribution networks, and the safety and health of distribution cables are the basis for ensuring the safe and reliable operation of distribution networks. Partial discharge is a tumor of distribution cables, which generally occurs at the middle head of distribution cables. Therefore, it is crucial to find partial discharge defects in the middle head of distribution cables and conduct reasonable health assessments.

[0003] There are currently two main methods to understand the health status of the middle joints of distribution cables. One is to perform a cable oscillation wave test during a power outage. The cable oscillation wave test is to apply an oscillation wave voltage to the distribution cable. If there are partial discharge defects in the distribution cable or the middle head, when the voltage is applied to a certain level, a partial discharge signal will be triggered. By collecting whether there is a partial discharge signal, it can be determined whether there is a partial discharge defect in the middle head of the distribution cable. Therefore, the cable oscillation wave test is a deterministic diagnosis, and the signals such as the partial discharge amount collected during the test can be used as early warning signals. The oscillation wave test is carried out during a power outage, which affects the reliability of power supply. Although it is actually implemented, the operation is relatively rare. The other is to install a ground wave partial discharge sensor to monitor the partial discharge amount of the middle head of the distribution cable online for evaluation. In practice, this method usually makes a judgment based on whether the collected partial discharge amount exceeds the limit. It is simple and convenient. In addition, this method does not stop the power supply online and does not affect the reliability of power supply. However, there are the following problems: on the one hand, the severity of partial discharge is characterized only by the partial discharge amount, and the evaluation is not comprehensive; on the other hand, the ground wave partial discharge sensor is a continuous online monitoring, and it starts to collect data from the smallest partial discharge amount according to the sensitivity. Although there is a partial discharge signal, it does not necessarily mean that the distribution cable is unhealthy, and it is difficult to calibrate and evaluate the health status of the middle joint of the distribution cable. Therefore, how to comprehensively and accurately determine the health status of the middle joint of the distribution cable based on the partial discharge information monitored online by the ground wave partial discharge sensor is a difficult problem. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a method, device, equipment and medium for evaluating the health of the intermediate head of a distribution cable, which can comprehensively and accurately determine the health status of the intermediate head of the distribution cable.

[0005] The technical solution adopted by the present invention to solve the technical problem is: to provide a method for health assessment of an intermediate head of a distribution cable, comprising the following steps:

[0006] Collect the historical data of oscillation wave tests and fault history of the middle head of the distribution cable in the distribution network to form a large database of oscillation wave tests and its element field values ​​and a typical type of defect partial discharge feature library;

[0007] The ground wave partial discharge sensor is used to periodically collect data from the middle head of the distribution cable to be evaluated, and the average partial discharge value, the maximum partial discharge value, and the average discharge times per cycle are obtained;

[0008] Calculate the average growth rate of the average partial discharge value, the average growth rate of the maximum partial discharge value and the average growth rate of the average number of discharges per cycle within the evaluation period;

[0009] According to the hierarchical analysis method, a hierarchical model is established, in which the main factors affecting the health of the distribution cable head include the average partial discharge value, the average growth rate of the average partial discharge value, the maximum partial discharge value, the average growth rate of the maximum partial discharge value, the average discharge times per cycle, and the average growth rate of the average discharge times per cycle;

[0010] Constructing a judgment matrix according to the relationship between the factors in the hierarchical structure model, and obtaining the weight of each factor by the square root method;

[0011] By comparing the oscillation wave test database and its element field values ​​with the typical defect partial discharge feature database, the evaluation value scores of each factor are quantitatively determined;

[0012] The comprehensive score value of the health assessment of the distribution cable intermediate head is calculated according to the weight of each factor and the evaluation value score of each factor, and the health status of the distribution cable intermediate head is determined according to the comprehensive score value of the health assessment of the distribution cable intermediate head.

[0013] Each data element field in the oscillation wave test database includes but is not limited to the following information: test cable model, test cable operating life, test cable head operating life, test cable annual average load, test cable annual maximum load, defect type, defect content, partial discharge amount, starting voltage PDIV, discharge interval and discharge concentration phase.

[0014] The average growth rate of the average partial discharge value is given by Calculated, where η PFAV is the average growth rate of the average PD value within the evaluation period T0, PFAV j is the average value of partial discharge in the jth hour within the evaluation period T0.

[0015] The average growth rate of the maximum partial discharge is given by Calculated, where η PFmax PFmax is the average growth rate of the maximum value of partial discharge in the evaluation period T0. jis the maximum value of partial discharge in the jth hour within the evaluation period T0.

[0016] The average growth rate of the average number of discharges per cycle is Calculated, η Num PFmax is the average growth rate of the average number of discharges per cycle within the evaluation period T0. j It is the average number of discharges per cycle in the jth hour within the evaluation period T0.

[0017] The step of constructing a judgment matrix according to the relationship between the factors in the hierarchical structure model specifically includes:

[0018] By comparing the factors pairwise, the relative importance of each factor can be determined.

[0019] A judgment matrix is ​​constructed based on the relative importance of each factor.

[0020] By comparing the oscillation wave test database and its element field values ​​with the typical type defect partial discharge feature library, the evaluation value scores of each factor are quantitatively determined, including:

[0021] According to the discharge interval and discharge concentration phase of the middle head of the distribution cable during the evaluation period, compare the typical type of defect partial discharge feature library to find the partial discharge defect type and its corresponding partial discharge volume interval average value PFAVXZ. If the evaluation period of the partial discharge volume average value PFAV If the value is greater than the average value of the partial discharge volume interval PFAVXZ, the evaluation value of the average value of the partial discharge volume PFAV is 100, and the rest are calculated according to Determine the assessment value score of the average partial discharge volume PFAV within the assessment period;

[0022] According to the discharge interval and discharge concentration phase of the middle head of the distribution cable during the evaluation period, compare the typical type of defect partial discharge feature library to find the partial discharge defect type and its corresponding upper limit value of the partial discharge volume interval PFAVSXZ. If the evaluation period of the maximum partial discharge volume PFmax If the value is greater than the upper limit of the partial discharge interval PFAVSXZ, the evaluation value of the maximum partial discharge value PFmax is 100, and the rest are calculated according to Determine the evaluation value score of the maximum partial discharge value PFmax within the evaluation period;

[0023] The evaluation score of the average number of discharges per cycle is determined by giving 1 point for each K number.

[0024] The evaluation score of the average growth rate of the average partial discharge volume is determined in such a way that if the average growth rate of the average partial discharge volume is negative, no score is given, and 1 point is given for every increase of m%;

[0025] The evaluation score of the average growth rate of the maximum value of partial discharge is determined in such a way that if the average growth rate of the maximum value of partial discharge is negative, no score is given, and 1 point is given for every increase of m%;

[0026] The evaluation score of the average growth rate of the average number of discharges per cycle is determined in the following manner: if the average growth rate of the average number of discharges per cycle is negative, no points will be awarded, and 1 point will be awarded for every m% increase.

[0027] The comprehensive score of the health assessment of the intermediate head of the distribution cable is Calculated, where L is the comprehensive score of the health assessment of the intermediate head of the distribution cable, P i is the evaluation score of the i-th factor, w i is the weight of the ith factor.

[0028] The technical solution adopted by the present invention to solve the technical problem is: to provide a health assessment device for an intermediate head of a distribution cable, comprising:

[0029] The collection module is used to collect the historical data of the oscillation wave test and the historical data of the faults of the middle head of the distribution cable in the distribution network, so as to form a large database of the oscillation wave test and its element field values ​​and a characteristic library of partial discharge of typical types of defects;

[0030] The acquisition module is used to use the ground wave partial discharge sensor to periodically collect data from the middle head of the distribution cable to be evaluated, and obtain the average partial discharge amount, the maximum partial discharge amount, and the average discharge number of the cycle;

[0031] A calculation module, used to calculate an average growth rate of an average partial discharge amount, an average growth rate of a maximum partial discharge amount, and an average growth rate of a cycle average discharge number within an evaluation period;

[0032] Establishing a module for establishing a hierarchical model according to the hierarchical analysis method, wherein the main factors affecting the health of the distribution cable head in the hierarchical model include the average partial discharge amount, the average growth rate of the average partial discharge amount, the maximum partial discharge amount, the average growth rate of the maximum partial discharge amount, the average discharge number per cycle, and the average growth rate of the average discharge number per cycle;

[0033] A construction module, used to construct a judgment matrix according to the relationship between the factors in the hierarchical structure model, and obtain the weight of each factor by the square root method;

[0034] The evaluation value scoring module is used to quantitatively determine the evaluation value scores of each factor by comparing the oscillation wave test database and its element field values ​​with the typical type defect partial discharge feature library;

[0035] The evaluation module is used to calculate the comprehensive score value of the health evaluation of the distribution cable intermediate head according to the weight of each factor and the evaluation value score of each factor, and determine the health status of the distribution cable intermediate head according to the comprehensive score value of the health evaluation of the distribution cable intermediate head.

[0036] The technical solution adopted by the present invention to solve its technical problem is: to 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 implements the steps of the above-mentioned distribution cable intermediate head health assessment method when executing the computer program.

[0037] The technical solution adopted by the present invention to solve its technical problem is: providing a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the steps of the above-mentioned distribution cable intermediate head health assessment method are implemented.

[0038] Beneficial Effects

[0039] Due to the adoption of the above-mentioned technical scheme, compared with the prior art, the present invention has the following advantages and positive effects: based on the online monitoring data of geomagnetic partial discharge, the present invention comprehensively evaluates the health status of the middle head of the distribution cable by using the analytic hierarchy process, including the average partial discharge amount, the average growth rate of the average partial discharge amount, the maximum partial discharge amount, the average growth rate of the maximum partial discharge amount, the average number of discharges per cycle, the average growth rate of the average number of discharges per cycle and other factors. When calculating the evaluation value, a typical type of defect partial discharge feature library is established according to the oscillation wave test data, which is used as a reference value for the health evaluation limit for optimization calculation, thereby being able to carry out deterministic quantitative evaluation and comprehensively and accurately determine the health status of the middle head of the distribution cable. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a flow chart of a method for evaluating the health of an intermediate head of a distribution cable according to a first embodiment of the present invention. DETAILED DESCRIPTION

[0041] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the appended claims of the application equally.

[0042] The first embodiment of the present invention relates to a method for evaluating the health of an intermediate connector of a distribution cable, such as Figure 1 As shown, the following steps are included:

[0043] Step 1, collect the oscillation wave test historical data and fault history data of the middle head of the distribution cable in the regional distribution network, and form an oscillation wave test database and its element field values. Each data element field in the database includes but is not limited to the following information {test cable model, test cable operating life, test cable head operating life, test cable annual average load, test cable annual maximum load, defect type, defect content, partial discharge, starting voltage PDIV, discharge interval, discharge concentration phase}.

[0044] Step 2: Based on the oscillation wave test database, a typical type of defect partial discharge feature library is established, as shown in Table 1.

[0045] Table 1 Typical type defect table

[0046]

[0047]

[0048]

[0049] (3) Select a distribution cable middle head equipped with a ground wave partial discharge sensor as the evaluation object.

[0050] (4) Collect the basic information of the intermediate head of the distribution cable and the corresponding distribution cable {test cable model, test cable operating life, test cable head operating life, test cable annual average load, test cable annual maximum load}.

[0051] (5) The ground wave partial discharge sensor installed at the middle head of the distribution cable collects data within a period of 1 s once every hour. The collected data include the average value PFAV of partial discharge within 1 s, the maximum value PFmax of partial discharge within 1 s, and the average number of discharges Num within 1 s. Data collection is continuous.

[0052] (6) Set the initial evaluation period T0 = 168h;

[0053] (7) Calculate the average growth rate η of the average PD value within the evaluation period PFAV , the average growth rate of the maximum partial discharge η PFmax , the average growth rate of the average discharge frequency per cycle η Num Three parameters;

[0054] Among them, the average growth rate of the average partial discharge value η PFAV Calculate according to the following formula:

[0055]

[0056] Among them, the average growth rate of the maximum partial discharge is η PFmax Calculate according to the following formula:

[0057]

[0058] Among them, the average growth rate of the average discharge frequency of the cycle is η Num Calculate according to the following formula:

[0059]

[0060] (8) According to the hierarchical analysis method, a hierarchical model is established. The main factors affecting the health of distribution cable heads include the average value of partial discharge PFAV, the average growth rate of the average value of partial discharge η PFAV , maximum partial discharge PFmax, average growth rate of maximum partial discharge η PFmax , the average discharge frequency Num, the average growth rate of the average discharge frequency η Num And six factors.

[0061] (9) Constructing the judgment matrix

[0062] 1) By comparing the influencing factors with each other, the relative importance of the influencing factors is determined, such as equally important is defined as 1, slightly important is defined as 3, relatively important is defined as 5, strongly important is defined as 7, strongly important is defined as 8, and extremely important is defined as 9, as follows:

[0063] Partial discharge volume average PFAV VS Partial discharge volume average PFAV: Equally important1;

[0064] Average partial discharge volume PFAV VS maximum partial discharge volume PFmax: PFmax is relatively slightly important 3;

[0065] The average value of partial discharge PFAV VS the average number of discharges per cycle Num: Num is relatively strong and important 5;

[0066] Average growth rate η of the average partial discharge volume PFAV VS the maximum partial discharge volume PFmax :ηPFAV is relatively strong and important 8;

[0067] Average growth rate η of the average partial discharge volume PFAV VS the maximum partial discharge volume PFmax :ηPFmax is relatively extremely important 9;

[0068] Average partial discharge volume PFAV VS average growth rate of average discharge times in a cycle η Num :ηNum is relatively strongly important 7;

[0069] Maximum partial discharge PFmax VS average number of discharges per cycle Num: PFmax is relatively slightly important 3;

[0070] The average growth rate η of the maximum partial discharge PFmax VS the average partial discharge PFAV : PFmax is relatively slightly important 3;

[0071] Maximum partial discharge PFmaxVS average growth rate of maximum partial discharge η PFmax : PFmax is relatively slightly important 3;

[0072] The average growth rate of the maximum partial discharge PFmaxVS the average discharge times in the cycle η Num : PFmax is relatively slightly important 3;

[0073] Average discharge times per cycle Num VS average growth rate of average partial discharge amount η PFAV :ηPFAV is relatively strong and important 8;

[0074] Average discharge times per cycle Num VS average growth rate of maximum partial discharge value η PFmax :ηPFmax is relatively extremely important 9;

[0075] Average discharge times per cycle Num VS Average growth rate of average discharge times per cycle η Num :ηNum is relatively strongly important 7;

[0076] The average growth rate of the average partial discharge volume η PFAV Average growth rate η of the maximum VS partial discharge PFmax :ηPFmax is relatively extremely important 9;

[0077] The average growth rate of the average partial discharge volume η PFAV The average growth rate of the average discharge frequency of the VS cycle η Num :ηNum is relatively strongly important 7;

[0078] The average growth rate of the maximum partial discharge η PFmax The average growth rate of the average discharge frequency of the VS cycle η Num ηPFmax is relatively strongly important9.

[0079] 2) By comparing the influencing factors, the judgment matrix is ​​obtained. The details are as follows:

[0080] PFAV PFmax Num ηPFAV ηPFmax ηNum PFAV 1 1 / 3 1 / 5 1 / 8 1 / 9 1 / 7 PFmax 3 1 1 / 3 1 / 3 1 / 3 1 / 3 Num 5 3 1 1 / 8 1 / 9 1 / 7 ηPFAV 8 3 8 1 1 / 9 1 / 7 ηPFmax 9 3 9 9 1 9 ηNum 7 3 7 7 1 / 9 1

[0081] 3) According to the square root method, the weights of various influencing factors are calculated. The weight w1 of the average partial discharge volume PFAV is 0.0249, the weight w2 of the maximum partial discharge volume PFmax is 0.2753, the weight w3 of the average number of discharges per cycle Num is 0.0425, and the average growth rate η of the average partial discharge volume is PFAVThe weight w4 is 0.0920, and the average growth rate of the maximum partial discharge is η PFmax The weight w5 is 0.3970, and the average growth rate of the average discharge frequency of the cycle is η Num The weight w6 is 0.1683.

[0082] (10) By comparing the oscillation wave test database and its element field values ​​with the typical type defect partial discharge feature library, the evaluation value scores of each factor are quantitatively determined.

[0083] 1) The evaluation score of the influencing factor local discharge interval average value PFAVXZ is defined as follows:

[0084] According to the discharge interval and discharge concentration phase of the middle head of the distribution cable during the evaluation period, compare the typical type of defect partial discharge feature library to find the partial discharge defect type and its corresponding partial discharge volume interval average value PFAVXZ. If the evaluation period of the partial discharge volume average value PFAV If the value is greater than the average value of the partial discharge volume interval PFAVXZ, the evaluation value of the average value of the partial discharge volume PFAV is 100, and the rest are calculated according to Determine the assessment value score of the average partial discharge volume PFAV within the assessment period.

[0085] 2) The evaluation value score of the influencing factor PFmax is defined as follows:

[0086] According to the discharge interval and discharge concentration phase of the middle head of the distribution cable during the evaluation period, compare the typical type of defect partial discharge feature library to find the partial discharge defect type and its corresponding upper limit value of the partial discharge range PFAVSXZ. If the value is greater than the upper limit of the partial discharge interval PFAVSXZ, the evaluation value of the maximum partial discharge value PFmax is 100, and the rest are calculated according to Determine the evaluation value score of the maximum partial discharge value PFmax within the evaluation period.

[0087] 3) The evaluation score of the influencing factor, average number of discharges per cycle Num, is defined as follows:

[0088] The evaluation value score of the average number of discharges per cycle Num is determined in a manner of 1 point for every 10 times, and the maximum score is 100 points.

[0089] 4) Average growth rate of the average value of the local discharge volume of influencing factors η PFAV The evaluation score is defined as follows:

[0090] The average growth rate of the average partial discharge volume η PFAV No points will be awarded for a negative value, and 1 point will be awarded for every 1% increase, with a maximum score of 100 points.

[0091] 5) Average growth rate η of the maximum value of the partial discharge volume PFmax The evaluation score is defined as follows:

[0092] The average growth rate of the maximum partial discharge η PFmax No points will be awarded for negative values, and 1 point will be awarded for every 1% increase, with a maximum score of 100 points.

[0093] 6) Influencing factors Average growth rate of average discharge frequency η Num The evaluation score is defined as follows:

[0094] Average growth rate of average discharge frequency per cycle η Num No points will be awarded for negative values, and 1 point will be awarded for every 1% increase, with a maximum score of 100 points.

[0095] (11) Calculate the comprehensive score of the health assessment of the intermediate head of the distribution cable Among them, L is the comprehensive score of the health assessment of the intermediate head of the distribution cable, P i is the evaluation score of the i-th factor, w i is the weight of the ith factor.

[0096] (12) The score value is divided into five intervals, namely, healthy L=0, sub-healthy L is 0 to 10, excluding zero, defect L is 10 to 60, excluding 10, serious defect L is 60 to 80, excluding zero, and critical defect L is 80 to 100, excluding 80. The health status of the distribution cable is determined according to the comprehensive score value of the health assessment of the distribution cable intermediate head obtained in step (11).

[0097] It is not difficult to find that according to the online monitoring data of geomagnetic partial discharge, the average partial discharge amount, the average growth rate of the average partial discharge amount, the maximum partial discharge amount, the average growth rate of the maximum partial discharge amount, the average number of discharges per cycle, the average growth rate of the average number of discharges per cycle and other factors are comprehensively considered, and then the hierarchical analysis method is used to compare the oscillation wave test big database and its element field values ​​with the typical type defect partial discharge feature library to quantitatively calculate the evaluation value, and a comprehensive evaluation is performed on the health status of the distribution cable middle head. When calculating the evaluation value, a typical type defect partial discharge feature library is established according to the oscillation wave test data, and it is optimized and calculated as a reference value for the health assessment limit, so that the health status of the distribution cable middle head can be determined comprehensively and accurately.

[0098] A second embodiment of the present invention relates to a health assessment device for an intermediate head of a distribution cable, comprising:

[0099] The collection module is used to collect the historical data of the oscillation wave test and the historical data of the faults of the middle head of the distribution cable in the distribution network, so as to form a large database of the oscillation wave test and its element field values ​​and a characteristic library of partial discharge of typical types of defects;

[0100] The acquisition module is used to use the ground wave partial discharge sensor to periodically collect data from the middle head of the distribution cable to be evaluated, and obtain the average partial discharge amount, the maximum partial discharge amount, and the average discharge number of the cycle;

[0101] A calculation module, used to calculate an average growth rate of an average partial discharge amount, an average growth rate of a maximum partial discharge amount, and an average growth rate of a cycle average discharge number within an evaluation period;

[0102] Establishing a module for establishing a hierarchical model according to the hierarchical analysis method, wherein the main factors affecting the health of the distribution cable head in the hierarchical model include the average partial discharge amount, the average growth rate of the average partial discharge amount, the maximum partial discharge amount, the average growth rate of the maximum partial discharge amount, the average discharge number per cycle, and the average growth rate of the average discharge number per cycle;

[0103] A construction module, used to construct a judgment matrix according to the relationship between the factors in the hierarchical structure model, and obtain the weight of each factor by the square root method;

[0104] The evaluation value scoring module is used to quantitatively determine the evaluation value scores of each factor by comparing the oscillation wave test database and its element field values ​​with the typical type defect partial discharge feature library;

[0105] The evaluation module is used to calculate the comprehensive score value of the health evaluation of the distribution cable intermediate head according to the weight of each factor and the evaluation value score of each factor, and determine the health status of the distribution cable intermediate head according to the comprehensive score value of the health evaluation of the distribution cable intermediate head.

[0106] The calculation module is Calculate the average growth rate of the average partial discharge volume, where η PFAV is the average growth rate of the average PD value within the evaluation period T0, PFAV j is the average value of partial discharge in the jth hour within the evaluation period T0.

[0107] The calculation module is Calculate the average growth rate of the maximum partial discharge, where η PFmax PFmax is the average growth rate of the maximum value of partial discharge in the evaluation period T0. j is the maximum value of partial discharge in the jth hour within the evaluation period T0.

[0108] The calculation module is Calculate the average growth rate of the average discharge frequency per cycle, where η Num PFmax is the average growth rate of the average number of discharges per cycle within the evaluation period T0. j It is the average number of discharges per cycle in the jth hour within the evaluation period T0.

[0109] The construction module comprises:

[0110] The importance determination unit is used to determine the relative importance of each factor by comparing each factor with the others;

[0111] The construction unit is used to construct a judgment matrix based on the relative importance of each factor.

[0112] The evaluation value scoring module includes:

[0113] The partial discharge average value evaluation unit is used to compare the typical type of defect partial discharge feature library according to the middle head discharge interval and discharge concentration phase of the distribution cable within the evaluation period, find the partial discharge defect type and its corresponding partial discharge interval average value PFAVXZ, if the evaluation period of the partial discharge average value PFAV If the value is greater than the average value of the partial discharge volume interval PFAVXZ, the evaluation value of the average value of the partial discharge volume PFAV is 100, and the rest are calculated according to Determine the assessment value score of the average partial discharge volume PFAV within the assessment period;

[0114] The maximum partial discharge value evaluation unit is used to compare the typical type of defect partial discharge feature library with the discharge interval and discharge concentration phase of the middle head of the distribution cable within the evaluation period, find the partial discharge defect type and its corresponding upper limit value of the partial discharge value interval PFAVSXZ, if the evaluation period of the maximum partial discharge value PFmax If the value is greater than the upper limit of the partial discharge interval PFAVSXZ, the evaluation value of the maximum partial discharge value PFmax is 100, and the rest are calculated according to Determine the evaluation value score of the maximum partial discharge value PFmax within the evaluation period;

[0115] The average discharge frequency evaluation unit is used to determine the evaluation value score of the average discharge frequency according to the method of 1 point for each K frequency;

[0116] An average growth rate evaluation unit for the average partial discharge volume, used to determine the evaluation value score of the average growth rate of the average partial discharge volume in the manner that if the average growth rate of the average partial discharge volume is negative, no score is given, and 1 point is given for each increase of m%;

[0117] An average growth rate evaluation unit for the maximum partial discharge amount, used to determine the evaluation value score of the average growth rate of the maximum partial discharge amount in the manner that if the average growth rate of the maximum partial discharge amount is negative, no score is given, and 1 point is given for each increase of m%;

[0118] The average growth rate evaluation unit of the average number of discharges per cycle is used to determine the evaluation value score of the average growth rate of the average number of discharges per cycle in the manner that if the average growth rate of the average number of discharges per cycle is negative, no score is given, and 1 point is given for each increase of m%.

[0119] The evaluation module is Calculate the comprehensive score of the health assessment of the intermediate head of the distribution cable, where L is the comprehensive score of the health assessment of the intermediate head of the distribution cable, P i is the evaluation score of the i-th factor, w i is the weight of the ith factor.

[0120] A third embodiment of the present invention relates to an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the distribution cable intermediate head health assessment method of the first embodiment when executing the computer program.

[0121] A fourth embodiment of the present invention relates to a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the steps of the method for evaluating the health of an intermediate head of a distribution cable of the first embodiment are implemented.

[0122] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage and optical storage, etc.) that contain computer-usable program code.

[0123] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0124] These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer-readable memory produce a manufactured product including an instruction method, which is implemented in the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0125] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process in the computer or other programmable device. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0126] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for health assessment of intermediate connectors of distribution cables, characterized in that: The following steps are involved: Collect the historical data of oscillation wave tests and fault history of the middle head of the distribution cable in the distribution network to form a large database of oscillation wave tests and its element field values ​​and a typical type of defect partial discharge feature library; The ground wave partial discharge sensor is used to periodically collect data from the middle head of the distribution cable to be evaluated, and the average partial discharge value, the maximum partial discharge value, and the average discharge times per cycle are obtained; Calculate the average growth rate of the average partial discharge amount, the average growth rate of the maximum partial discharge amount, and the average growth rate of the average number of discharges per cycle within the evaluation period; According to the hierarchical analysis method, a hierarchical model is established, in which the main factors affecting the health of the distribution cable head include the average partial discharge value, the average growth rate of the average partial discharge value, the maximum partial discharge value, the average growth rate of the maximum partial discharge value, the average discharge times per cycle, and the average growth rate of the average discharge times per cycle; Constructing a judgment matrix according to the relationship between the factors in the hierarchical structure model, and obtaining the weight of each factor by the square root method; By comparing the oscillation wave test database and its element field values ​​with the typical defect partial discharge feature database, the evaluation value scores of each factor are quantitatively determined; The comprehensive score value of the health assessment of the distribution cable intermediate head is calculated according to the weight of each factor and the evaluation value score of each factor, and the health status of the distribution cable intermediate head is determined according to the comprehensive score value of the health assessment of the distribution cable intermediate head.

2. The method for health assessment of intermediate connectors of distribution cables according to claim 1, characterized in that: Each data element field in the oscillation wave test database includes but is not limited to the following information: test cable model, test cable operating life, test cable head operating life, test cable annual average load, test cable annual maximum load, defect type, defect content, partial discharge amount, starting voltage PDIV, discharge interval and discharge concentration phase.

3. The method for health assessment of intermediate connectors of distribution cables according to claim 1, characterized in that: The average growth rate of the average partial discharge value is given by Calculated, where η PFAV is the average growth rate of the average PD value within the evaluation period T0, PFAV j is the average value of partial discharge in the jth hour within the evaluation period T0.

4. The method for health assessment of intermediate connectors of distribution cables according to claim 1, characterized in that: The average growth rate of the maximum partial discharge is given by Calculated, where η PFmax PFmax is the average growth rate of the maximum value of partial discharge in the evaluation period T0. j is the maximum value of partial discharge in the jth hour within the evaluation period T0.

5. The method for health assessment of intermediate connectors of distribution cables according to claim 1, characterized in that: The average growth rate of the average number of discharges per cycle is Calculated, η Num PFmax is the average growth rate of the average number of discharges per cycle within the evaluation period T0. j It is the average number of discharges per cycle in the jth hour within the evaluation period T0.

6. The method for health assessment of intermediate connectors of distribution cables according to claim 1, characterized in that: The step of constructing a judgment matrix according to the relationship between the factors in the hierarchical structure model specifically includes: By comparing the factors pairwise, the relative importance of each factor can be determined. A judgment matrix is ​​constructed based on the relative importance of each factor.

7. The method for health assessment of intermediate connectors of distribution cables according to claim 1, characterized in that: By comparing the oscillation wave test database and its element field values ​​with the typical type defect partial discharge feature library, the evaluation value scores of each factor are quantitatively determined, including: According to the discharge interval and discharge concentration phase of the middle head of the distribution cable during the evaluation period, compare the typical type of defect partial discharge feature library to find the partial discharge defect type and its corresponding partial discharge volume interval average value PFAVXZ. If the evaluation period of the partial discharge volume average value PFAV If the value is greater than the average value of the partial discharge volume interval PFAVXZ, the evaluation value of the average value of the partial discharge volume PFAV is 100, and the rest are calculated according to Determine the assessment value score of the average partial discharge volume PFAV within the assessment period; According to the discharge interval and discharge concentration phase of the middle head of the distribution cable during the evaluation period, compare the typical type of defect partial discharge feature library to find the partial discharge defect type and its corresponding upper limit value of the partial discharge volume interval PFAVSXZ. If the evaluation period of the maximum partial discharge volume PFmax If the value is greater than the upper limit of the partial discharge interval PFAVSXZ, the evaluation value of the maximum partial discharge value PFmax is 100, and the rest are calculated according to Determine the evaluation value score of the maximum partial discharge value PFmax within the evaluation period; The evaluation score of the average number of discharges per cycle is determined by giving 1 point for each K number. The evaluation score of the average growth rate of the average partial discharge volume is determined in such a way that if the average growth rate of the average partial discharge volume is negative, no score is given, and 1 point is given for every increase of m%; The evaluation score of the average growth rate of the maximum value of partial discharge is determined in such a way that if the average growth rate of the maximum value of partial discharge is negative, no score is given, and 1 point is given for every increase of m%; The evaluation score of the average growth rate of the average number of discharges per cycle is determined in the following manner: if the average growth rate of the average number of discharges per cycle is negative, no points will be awarded, and 1 point will be awarded for every m% increase.

8. The method for health assessment of intermediate connectors of distribution cables according to claim 1, characterized in that: The comprehensive score of the health assessment of the intermediate head of the distribution cable is Calculated, where L is the comprehensive score of the health assessment of the intermediate head of the distribution cable, P i is the evaluation score of the i-th factor, w i is the weight of the ith factor.

9. A health assessment device for an intermediate head of a distribution cable, characterized in that: include: The collection module is used to collect the historical data of the oscillation wave test and the historical data of the faults of the middle head of the distribution cable in the distribution network, so as to form a large database of the oscillation wave test and its element field values ​​and a characteristic library of partial discharge of typical types of defects; The acquisition module is used to use the ground wave partial discharge sensor to periodically collect data from the middle head of the distribution cable to be evaluated, and obtain the average partial discharge amount, the maximum partial discharge amount, and the average discharge number of the cycle; A calculation module, used to calculate an average growth rate of an average partial discharge amount, an average growth rate of a maximum partial discharge amount, and an average growth rate of a cycle average discharge number within an evaluation period; Establishing a module for establishing a hierarchical model according to the hierarchical analysis method, wherein the main factors affecting the health of the distribution cable head in the hierarchical model include the average partial discharge amount, the average growth rate of the average partial discharge amount, the maximum partial discharge amount, the average growth rate of the maximum partial discharge amount, the average discharge number per cycle, and the average growth rate of the average discharge number per cycle; A construction module, used to construct a judgment matrix according to the relationship between the factors in the hierarchical structure model, and obtain the weight of each factor by the square root method; The evaluation value scoring module is used to quantitatively determine the evaluation value scores of each factor by comparing the oscillation wave test database and its element field values ​​with the typical type defect partial discharge feature library; The evaluation module is used to calculate the comprehensive score value of the health evaluation of the distribution cable intermediate head according to the weight of each factor and the evaluation value score of each factor, and determine the health status of the distribution cable intermediate head according to the comprehensive score value of the health evaluation of the distribution cable intermediate head.

10. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of the method for evaluating the health of an intermediate head of a distribution cable as claimed in any one of claims 1 to 7 are implemented.

11. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method for evaluating the health of an intermediate head of a distribution cable as claimed in any one of claims 1 to 7 are implemented.

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