Method and device for determining state of main insulation of high-voltage cable, and electronic equipment

Abstract

The invention discloses a high-voltage cable main insulation state determination method and device and electronic equipment, and relates to the field of power grid safety or other related technical fields, and the method comprises the steps: collecting the current data of a high-voltage cable section and the voltage data of a transformer substation corresponding to the high-voltage cable section; calculating a first-class phase initial value corresponding to the voltage of the high-voltage cable section based on the voltage data, and correcting the first-class phase initial value to obtain a first-class phase value corresponding to the voltage of the high-voltage cable section; calculating a second type phase value corresponding to the leakage current of the high-voltage cable section based on the current data; and calculating the dielectric loss of the high-voltage cable section based on the first type phase value and the second type phase value, determining the insulation state of the main insulation part of the high-voltage cable section, and generating a state monitoring result of the main insulation of the high-voltage cable based on the insulation state. According to the invention, the technical problem that the accuracy of the measurement result is low when the insulation state of the main insulation of the high-voltage cable is measured in the prior art is solved.

Description

Technical Field

[0001] The present invention relates to the field of power grid safety or other related technical fields, and in particular to a method and device for determining the state of a high-voltage cable main insulation, and electronic equipment. Background Art

[0002] With the development of the electric power industry, power cables are playing an increasingly important role in the power system. Due to the widespread use of power cables, the operation safety of power cables is particularly important, and the insulation performance of the main insulation part of the power cable is crucial to the operation safety of the power cable.

[0003] In the related technology, the methods for determining the insulation state of the main insulation mainly include: relative dielectric constant method, angle difference method based on the voltage at both ends of the cable, phase relative method, etc. Among them, the relative dielectric constant method monitors the main insulation leakage current of the high-voltage cable section online and uses the formula Calculate the capacitance and then calculate the relative dielectric constant of the cross-connected small section. According to the change of the relative dielectric constant of the cross-connected small section, the insulation state of the main insulation is judged. This insulation state monitoring method based on the relative dielectric constant has low calculation accuracy. The angle difference method based on the voltage at both ends of the cable is used for high-voltage cables with both ends on land and both outlets. The voltage U at both ends of the high-voltage cable can be synchronously measured at both ends using GPS or Beidou synchronization technology. 1 ,U 2 and current I 1 ,I 2 , then calculate Then by Calculate the voltage phase φ U ,Depend on Calculate the current phase φ I ,use The angle difference is calculated to evaluate the insulation state of the main insulation of the cable. This measurement method is only applicable to high-voltage cable lines with special structures. It is not universal and has low measurement accuracy. The measurement results obtained are less accurate. The phase-to-phase relative method uses the relative phase difference of the phase current in the cross-connected cable system to evaluate the insulation state of the cable segment. This relative calculation method has a lower measurement accuracy.

[0004] In summary, the state measurement method of the main insulation of the high-voltage cable in the related art has high measurement requirements, is not universal, and has low accuracy of the measurement results.

[0005] To address the above-mentioned problems, no effective solution has been proposed yet. Summary of the invention

[0006] The embodiments of the present invention provide a method and device for determining the state of the main insulation of a high-voltage cable, and an electronic device, so as to at least solve the technical problem in the related art that when measuring the insulation state of the main insulation of a high-voltage cable, the measurement result has low accuracy.

[0007] According to one aspect of an embodiment of the present invention, a method for determining the state of the main insulation of a high-voltage cable is provided, comprising: determining a high-voltage cable segment to be monitored, collecting current data of the high-voltage cable segment and voltage data of a substation corresponding to the high-voltage cable segment, wherein the current data comprises an input current and an output current of the high-voltage cable segment, the input current represents a current input from the substation to a metal sheath of the high-voltage cable segment, the output current refers to a current output from the high-voltage cable segment to the metal sheath, and the voltage data represents a three-phase voltage value of the substation; calculating a first-type phase initial value corresponding to the voltage of the high-voltage cable segment based on the voltage data of the substation, and calculating the first-type phase initial value based on the voltage data of the substation; The first type of phase initial value is corrected based on a phase correction model to obtain a first type of phase value corresponding to the voltage of the high-voltage cable segment, wherein the phase correction model is a model pre-constructed based on a back propagation neural network for correcting the phase value of the voltage of the high-voltage cable segment; a second type of phase value corresponding to the leakage current of the high-voltage cable segment is calculated based on the current data of the high-voltage cable segment; the dielectric loss of the high-voltage cable segment is calculated based on the first type of phase value and the second type of phase value, and the insulation state of the main insulation part of the high-voltage cable segment is determined based on the dielectric loss, and the status monitoring result of the main insulation of the high-voltage cable is generated based on the insulation state of the main insulation part of the high-voltage cable segment.

[0008] Optionally, the step of calculating the first type of phase initial value corresponding to the voltage of the high-voltage cable segment based on the voltage data of the substation includes: obtaining the grid frequency and the data sampling frequency, and correcting the grid frequency based on the voltage data of the substation to obtain the corrected grid frequency, wherein the grid frequency represents the frequency of the alternating current in the power system, and the data sampling frequency represents the sampling frequency of the data acquisition device when collecting the current data of the high-voltage cable segment and the voltage data of the substation corresponding to the high-voltage cable segment; calculating the number of sampling points within a sampling cycle based on the data sampling frequency and the corrected grid frequency; calculating the phase value corresponding to the voltage of the substation based on the three-phase voltage values ​​of each sampling point within a sampling cycle and the number of sampling points, and using the phase value corresponding to the voltage of the substation as the first type of phase initial value corresponding to the voltage of the high-voltage cable segment.

[0009] Optionally, the grid frequency is corrected based on the voltage data of the substation to obtain the corrected grid frequency, the step comprising: calculating the number of initial sampling points within a sampling cycle based on the grid frequency and the data sampling frequency; selecting two adjacent sampling cycles to obtain a first sampling cycle and a second sampling cycle; calculating a phase value corresponding to the voltage of the substation within the first sampling cycle based on the three-phase voltage values ​​of each sampling point within the first sampling cycle and the initial number of sampling points; calculating a phase value corresponding to the voltage of the substation within the second sampling cycle based on the three-phase voltage values ​​of each sampling point within the second sampling cycle and the initial number of sampling points; correcting the grid frequency based on the phase value corresponding to the voltage of the substation within the first sampling cycle and the phase value corresponding to the voltage of the substation within the second sampling cycle to obtain the corrected grid frequency.

[0010] Optionally, the step of correcting the first type of phase initial value based on the phase correction model to obtain the first type of phase value corresponding to the voltage of the high-voltage cable segment includes: obtaining the three-phase current and three-phase power factor of the cable main core to obtain the three-phase current and three-phase power factor of the high-voltage cable segment; obtaining the length of the high-voltage cable segment to be monitored to obtain the cable length value; obtaining the distance value between the first high-voltage cable segment and the substation, wherein the first high-voltage cable segment represents the high-voltage cable segment closest to the substation; inputting the three-phase current, the three-phase power factor, the cable length value and the distance value between the first high-voltage cable segment and the substation of the high-voltage cable segment into the phase correction model, and outputting the phase correction value corresponding to the voltage of the high-voltage cable segment; correcting the first type of phase initial value based on the phase correction value to obtain the first type of phase value corresponding to the voltage of the high-voltage cable segment.

[0011] Optionally, the step of calculating the second type of phase value corresponding to the leakage current of the high-voltage cable segment based on the current data of the high-voltage cable segment includes: calculating the number of sampling points within a sampling cycle based on the data sampling frequency and the corrected grid frequency; calculating the leakage current of each sampling point of the high-voltage cable segment within a sampling cycle based on the input current and output current of each sampling point within a sampling cycle in the current data of the high-voltage cable segment; calculating the second type of phase value corresponding to the leakage current of the high-voltage cable segment based on the leakage current of each sampling point of the high-voltage cable segment within a sampling cycle and the number of sampling points.

[0012] Optionally, the phase correction model is pre-constructed, and the step of constructing the phase correction model includes: generating a cable simulation model for a high-voltage cable line, and constructing a sample data set based on the cable simulation model, wherein the sample data set includes: the three-phase current and three-phase power factor of the cable main core on the high-voltage cable line, the distance value between the substation and the first high-voltage cable segment, the length value of each of the high-voltage cable segments on the high-voltage cable line, and the phase correction value corresponding to the voltage of each of the high-voltage cable segments on the high-voltage cable line; constructing an initial cable correction model based on the back propagation neural network; dividing the sample data set based on a preset division ratio to obtain a training set and a test set; iteratively training the initial cable correction model through the training set to obtain the trained cable correction model; testing the trained cable correction model based on the test set to obtain a test result, and when the test result indicates that the cable correction model passes the test, the trained cable correction model is obtained.

[0013] Optionally, before determining the high-voltage cable segment to be monitored, it also includes: configuring a voltage monitoring module for the substation; configuring a current acquisition module for the high-voltage cable segment; building a fiber optic communication network, and connecting the voltage monitoring module and the current acquisition module based on the fiber optic communication network.

[0014] According to another aspect of an embodiment of the present invention, a device for determining the state of the main insulation of a high-voltage cable is also provided, comprising: a collection unit, for determining a high-voltage cable segment to be monitored, collecting current data of the high-voltage cable segment and voltage data of a substation corresponding to the high-voltage cable segment, wherein the current data comprises an input current and an output current of the high-voltage cable segment, the input current representing the current input from the substation to the metal sheath of the high-voltage cable segment, the output current representing the current output from the high-voltage cable segment to the metal sheath, and the voltage data representing the three-phase voltage value of the substation; a correction unit, for calculating a first-type phase initial value corresponding to the voltage of the high-voltage cable segment based on the voltage data of the substation, and based on the voltage data of the substation The first type of phase initial value is corrected based on a phase correction model to obtain a first type of phase value corresponding to the voltage of the high-voltage cable segment, wherein the phase correction model is a model pre-constructed based on a back propagation neural network for correcting the phase value of the voltage of the high-voltage cable segment; a calculation unit is used to calculate a second type of phase value corresponding to the leakage current of the high-voltage cable segment based on the current data of the high-voltage cable segment; a determination unit is used to calculate the dielectric loss of the high-voltage cable segment based on the first type of phase value and the second type of phase value, and determine the insulation state of the main insulation part of the high-voltage cable segment based on the dielectric loss, and generate a status monitoring result of the main insulation of the high-voltage cable based on the insulation state of the main insulation part of the high-voltage cable segment.

[0015] Optionally, the correction unit includes: a first correction module, used to obtain the grid frequency and the data sampling frequency, and correct the grid frequency based on the voltage data of the substation to obtain the corrected grid frequency, wherein the grid frequency represents the frequency of the alternating current in the power system, and the data sampling frequency represents the sampling frequency of the data acquisition device when collecting the current data of the high-voltage cable segment and the voltage data of the substation corresponding to the high-voltage cable segment; a first calculation module, used to calculate the number of sampling points within a sampling cycle based on the data sampling frequency and the corrected grid frequency; a second calculation module, used to calculate the phase value corresponding to the voltage of the substation based on the three-phase voltage values ​​of each sampling point within a sampling cycle and the number of sampling points, and use the phase value corresponding to the voltage of the substation as the first type of phase initial value corresponding to the voltage of the high-voltage cable segment.

[0016] Optionally, the first correction module includes: a first calculation submodule, used to calculate the initial number of sampling points within a sampling cycle based on the grid frequency and the data sampling frequency; a first selection submodule, used to select two adjacent sampling cycles to obtain a first sampling cycle and a second sampling cycle; a second calculation submodule, used to calculate the phase value corresponding to the voltage of the substation within the first sampling cycle based on the three-phase voltage values ​​of each sampling point within the first sampling cycle and the initial number of sampling points; a third calculation submodule, used to calculate the phase value corresponding to the voltage of the substation within the second sampling cycle based on the three-phase voltage values ​​of each sampling point within the second sampling cycle and the initial number of sampling points; the first correction submodule, used to correct the grid frequency based on the phase value corresponding to the voltage of the substation within the first sampling cycle and the phase value corresponding to the voltage of the substation within the second sampling cycle to obtain the corrected grid frequency.

[0017] Optionally, the correction unit includes: a first acquisition module, used to acquire the three-phase current and three-phase power factor of the cable main core, and obtain the three-phase current and three-phase power factor of the high-voltage cable segment; a second acquisition module, used to acquire the length of the high-voltage cable segment to be monitored, and obtain the cable length value; a third acquisition module, used to acquire the distance value between the first high-voltage cable segment and the substation, wherein the first high-voltage cable segment represents the high-voltage cable segment closest to the substation; a first output module, used to input the three-phase current, the three-phase power factor, the cable length value and the distance value between the first high-voltage cable segment and the substation into the phase correction model, and output the phase correction value corresponding to the voltage of the high-voltage cable segment; a second correction module, used to correct the first type of phase initial value based on the phase correction value, and obtain the first type of phase value corresponding to the voltage of the high-voltage cable segment.

[0018] Optionally, the calculation unit includes: a third calculation module, used to calculate the number of sampling points within a sampling cycle based on the data sampling frequency and the corrected grid frequency; a fourth calculation module, used to calculate the leakage current of each sampling point of the high-voltage cable segment within a sampling cycle based on the input current and output current of each sampling point within a sampling cycle in the current data of the high-voltage cable segment; a fifth calculation module, used to calculate the second type phase value corresponding to the leakage current of the high-voltage cable segment based on the leakage current of each sampling point of the high-voltage cable segment within a sampling cycle and the number of sampling points.

[0019] Optionally, the state determination device for the main insulation of the high-voltage cable also includes: a first construction module, which is used to generate a cable simulation model for the high-voltage cable line, and construct a sample data set based on the cable simulation model, wherein the sample data set includes: the three-phase current and three-phase power factor of the cable main core on the high-voltage cable line, the distance value between the substation and the first high-voltage cable segment, the length value of each of the high-voltage cable segments on the high-voltage cable line, and the phase correction value corresponding to the voltage of each of the high-voltage cable segments on the high-voltage cable line; a second construction module, which is used to construct an initial cable correction model based on the back propagation neural network; a first division module, which is used to divide the sample data set based on a preset division ratio to obtain a training set and a test set; a first training module, which is used to iteratively train the initial cable correction model through the training set to obtain the trained cable correction model; a first testing module, which is used to test the trained cable correction model based on the test set to obtain a test result, and when the test result indicates that the cable correction model passes the test, the trained cable correction model is obtained.

[0020] Optionally, the device for determining the status of the main insulation of the high-voltage cable also includes: a first configuration module, used to configure a voltage monitoring module for the substation; a second configuration module, used to configure a current acquisition module for the high-voltage cable segment; a first connection module, used to construct a fiber-optic communication network, and connect the voltage monitoring module and the current acquisition module based on the fiber-optic communication network.

[0021] According to another aspect of an embodiment of the present invention, a computer-readable storage medium is also provided, wherein the computer-readable storage medium includes a stored computer program, wherein when the computer program is running, the device where the computer-readable storage medium is located is controlled to execute any of the above-mentioned methods for determining the status of the main insulation of a high-voltage cable.

[0022] According to another aspect of an embodiment of the present invention, there is also provided an electronic device, comprising one or more processors and a memory, wherein the memory is used to store one or more programs, wherein when the one or more programs are executed by the one or more processors, the one or more processors implement any one of the above-mentioned methods for determining the status of the main insulation of a high-voltage cable.

[0023] In the present application, the following steps are performed: determining a high-voltage cable segment to be monitored, collecting current data of the high-voltage cable segment and voltage data of the substation corresponding to the high-voltage cable segment, wherein the current data includes input current and output current of the high-voltage cable segment, the input current represents the current input from the substation to the metal sheath of the high-voltage cable segment, the output current refers to the current output from the metal sheath of the high-voltage cable segment, the voltage data represents the three-phase voltage value of the substation, the first type of phase initial value corresponding to the voltage of the high-voltage cable segment is calculated based on the voltage data of the substation, and the first type of phase initial value is corrected based on a phase correction model to obtain the first type of phase value corresponding to the voltage of the high-voltage cable segment, wherein the phase correction model is a model pre-constructed based on a back propagation neural network for correcting the phase value of the voltage of the high-voltage cable segment, and then the second type of phase value corresponding to the leakage current of the high-voltage cable segment is calculated based on the current data of the high-voltage cable segment, and finally the dielectric loss of the high-voltage cable segment is calculated based on the first type of phase value and the second type of phase value, and the insulation state of the main insulation part of the high-voltage cable segment is determined based on the dielectric loss, and the state monitoring result of the main insulation of the high-voltage cable is generated based on the insulation state of the main insulation part of the high-voltage cable segment.

[0024] In the present application, when evaluating the insulation state of the main insulation of a high-voltage cable segment, the current data of the high-voltage cable segment and the voltage data of the substation to which the high-voltage cable segment is connected are collected, and the initial phase value of the voltage is calculated based on the voltage data. The initial phase value is corrected by a pre-constructed phase correction model to obtain the phase value corresponding to the voltage of the high-voltage cable segment, and the phase value of the leakage current is calculated by the current data, thereby calculating the dielectric loss of the high-voltage cable segment according to the phase value of the voltage and the phase value of the current, and determining the insulation state of the main insulation part of the high-voltage cable segment through the dielectric loss. The measurement method is simple and suitable for any measurement scenario, achieving the purpose of precise measurement, and achieving the effect of improving the accuracy of the insulation state measurement results, thereby solving the technical problem of low accuracy of the measurement results when measuring the insulation state of the main insulation of the high-voltage cable in the related art. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0026] Figure 1 is a flow chart of an optional method for determining the state of the main insulation of a high-voltage cable according to an embodiment of the present invention;

[0027] Figure 2 is a schematic diagram of an optional cross-interconnection portion of a high-voltage cable according to an embodiment of the present invention;

[0028] Figure 3 is a schematic diagram of a dielectric loss measurement principle of an optional high-voltage cable interconnection part according to an embodiment of the present invention;

[0029] Figure 4 is a schematic diagram of an optional high-voltage cable segment measuring device according to an embodiment of the present invention;

[0030] Figure 5 is a schematic diagram of an optional device for determining the state of the main insulation of a high-voltage cable according to an embodiment of the present invention;

[0031] Figure 6 The hardware structure block diagram of an electronic device (or mobile device) for determining the state of the main insulation of a high-voltage cable according to an embodiment of the present invention. DETAILED DESCRIPTION

[0032] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0033] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0034] It should be noted that the method for determining the state of the main insulation of a high-voltage cable and the device thereof in the present application can be used in the field of power grid safety when the working state of the main insulation of the high-voltage cable is determined based on the dielectric loss of the high-voltage cable segment, and can also be used in any field other than the field of power grid safety when the working state of the main insulation of the high-voltage cable is determined based on the dielectric loss of the high-voltage cable segment. The present application does not limit the application field of the method for determining the state of the main insulation of the high-voltage cable and the device thereof.

[0035] It should be noted that the relevant information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are information and data authorized by the user or fully authorized by all parties, and the collection, storage, use, processing, transmission, provision, disclosure and application of the relevant data comply with the relevant laws, regulations and standards of the relevant regions, take necessary confidentiality measures, do not violate public order and good customs, and provide corresponding operation entrances for users to choose to authorize or refuse. For example, an interface is set up between this system and relevant users or organizations. Before obtaining relevant information, it is necessary to send an acquisition request to the aforementioned user or organization through the interface, and obtain relevant information after receiving the consent information fed back by the aforementioned user or organization.

[0036] It should be noted that in this application, when collecting and analyzing customer information, corresponding operation entrances are provided for users to choose to agree or reject the automated decision-making results; if the user chooses to reject, the expert decision-making process will be entered.

[0037] The following embodiments of the present invention can be applied to various high-voltage cable main insulation state determination systems / applications / devices. The present invention collects the current data of the high-voltage cable segment and the voltage data of the substation in real time through the online monitoring equipment of the high-voltage cable segment. The measurement method is simple and applicable to general measurement environments. The modules in the device can synchronize data through the optical fiber communication network to achieve high-precision data synchronization in harsh environments, which helps to improve the accuracy of state measurement. At the same time, the embodiment of the present invention calculates the phase value of the substation voltage based on the voltage data, and corrects the phase value of the substation voltage to obtain the phase value of the high-voltage cable segment voltage, and calculates the phase value of the leakage current of the high-voltage cable segment based on the current data, and then calculates the dielectric loss of the high-voltage cable segment according to the phase value of the voltage and the phase value of the leakage current, and determines the insulation state of the main insulation of the high-voltage cable segment through the dielectric loss, thereby achieving accurate measurement of the insulation state and ensuring the accuracy of the measurement results.

[0038] The present invention is described in detail below in conjunction with various embodiments.

[0039] Embodiment 1

[0040] According to an embodiment of the present invention, an embodiment of a method for determining the state of the main insulation of a high-voltage cable is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0041] Figure 1 is a flow chart of an optional method for determining the state of the main insulation of a high-voltage cable according to an embodiment of the present invention, such as Figure 1 As shown, the method comprises the following steps:

[0042] Step S101, determining a high-voltage cable segment to be monitored, and collecting current data of the high-voltage cable segment and voltage data of a substation corresponding to the high-voltage cable segment.

[0043] In the power system, high-voltage cables are used to transmit electric energy efficiently, over long distances and safely. They are the main medium for transmitting electric energy in the power system and are responsible for transmitting electric energy from power plants or substations to user terminals or other power facilities. One end of the high-voltage cable is connected to power transmission equipment such as substations, and the other end is connected to power consumption equipment such as user terminals. High-voltage cables are usually located underground, replacing traditional overhead lines. Underground high-voltage cables can effectively avoid the impact of weather and environmental factors on power transmission, while reducing damage to urban landscapes and improving power supply reliability.

[0044] The main insulation of high-voltage cables is the key insulation layer located between the cable conductor (i.e. the metal wire through which the current passes) and the grounded shield layer (or metal sheath). The main function of the main insulation is to provide electrical isolation, ensuring that the current only flows inside the conductor and does not leak into the external environment. As the core insulation layer inside the cable, it directly determines the electrical performance and safety level of the cable, while the sheath and other protective layers outside the cable are to increase the working strength and environmental adaptability of the cable. In high-voltage cables, the performance of the main insulation is particularly important because it needs to maintain a good insulation state under high voltage and long-term operating conditions to prevent electrical failures and ensure the efficiency and safety of power transmission.

[0045] For high-voltage cables deployed underground, it is difficult to evaluate the insulation status of their main insulation. How to efficiently and easily measure the insulation status of the main insulation to ensure the safe operation of high-voltage cables is an important issue in the field of power safety.

[0046] High-voltage cable segment refers to the shielding layer grounding technology of high-voltage single-core cable. In order to reduce the induced current of the cable core current on the shielding layer, the whole cable is divided into several small segments of equal or substantially equal length. Insulating joints are installed between each small segment. When evaluating the insulation status of the main insulation of the high-voltage cable, it is only necessary to determine the insulation status of the main insulation of multiple independent high-voltage cable segments.

[0047] Figure 2 is a schematic diagram of an optional cross-connection part of a high-voltage cable according to an embodiment of the present invention, such as Figure 2 As shown, the high-voltage cable cross-connection part is composed of nine high-voltage cable sections, namely A1, B1, C1, A2, B2, C2, A3, B3 and C3, which also include a left grounding box GL, a right grounding box GR and cross-connection boxes JA1 and JA2.

[0048] Optionally, before determining the high-voltage cable segment to be monitored, it also includes: configuring a voltage monitoring module for the substation; configuring a current acquisition module for the high-voltage cable segment; building a fiber optic communication network, and connecting the voltage monitoring module and the current acquisition module based on the fiber optic communication network.

[0049] It should be noted that the embodiment of the present invention calculates the dielectric loss of the high-voltage cable segment by collecting the current data of each high-voltage cable segment and the voltage data of the substation, and determines the insulation state of the main insulation of the high-voltage cable segment through the dielectric loss. Before measuring and evaluating the insulation state of the main insulation of the high-voltage cable segment, the embodiment of the present invention configures an online insulation state monitoring device for the high-voltage cable. The online insulation state monitoring device includes a voltage monitoring module deployed in the substation and a current acquisition module deployed on both sides of each high-voltage cable segment, and an optical fiber communication network connecting the voltage monitoring module and each current acquisition module. The optical fiber communication network can solve the problem of data synchronization and transmission failure caused by the absence of GPS and Beidou signals in the cable trench in the traditional method, improve the data synchronization accuracy, and ensure that data synchronization can be quickly achieved even in harsh environments, thereby realizing online monitoring of the main insulation state of the high-voltage cable.

[0050] It should be noted that when evaluating the insulation state of the main insulation of the high-voltage cable segment, the voltage data of the substation is collected through the voltage monitoring module, and the voltage data includes the three-phase voltage value of the substation, and the current data of the high-voltage cable segment is collected through the current collection module. The current data includes the input current and output current of the high-voltage cable segment. The input current represents the current input from the substation to the metal sheath of the high-voltage cable segment, and the output current refers to the current output from the metal sheath of the high-voltage cable segment. The voltage data represents the three-phase voltage value of the substation.

[0051] Figure 3 is a schematic diagram of a dielectric loss measurement principle of an optional high-voltage cable interconnection part according to an embodiment of the present invention, such as Figure 3 As shown, the voltage monitoring unit (corresponding to the above voltage detection module) is deployed at one end of the substation and is responsible for collecting the three-phase voltage of the substation ABC. A current collection unit is deployed in each cross-connected high-voltage cable segment. Figure 3In the invention, a current acquisition unit (corresponding to the above-mentioned current acquisition module) 1 is deployed between the substation and the three high-voltage cable segments A1, B1, and C1, for collecting the input current of the three high-voltage cable segments A1, B1, and C1; a current acquisition unit (corresponding to the above-mentioned current acquisition module) 2 is deployed between the three high-voltage cable segments A1, B1, and C1 and the three high-voltage cable segments A2, B2, and C2, for collecting the output current of the three high-voltage cable segments A1, B1, and C1 and the input current of the three high-voltage cable segments A2, B2, and C2; 2. A current acquisition unit (corresponding to the above-mentioned current acquisition module) 3 is deployed between the three high-voltage cable segments 2 and C2 and the three high-voltage cable segments A3, B3, and C3, which is used to collect the output current of the three high-voltage cable segments A2, B2, and C2 and the input current of the three high-voltage cable segments A3, B3, and C3. A current acquisition unit (corresponding to the above-mentioned current acquisition module) 4 is deployed between the three high-voltage cable segments A3, B3, and C3 and the three high-voltage cable segments A4, B4, and C4, which is used to collect the output current of the three high-voltage cable segments A3, B3, and C3.

[0052] Figure 4 is a schematic diagram of an optional high-voltage cable segment measuring device according to an embodiment of the present invention, such as Figure 4 As shown, the high-voltage cable segment measurement equipment spans the station end (corresponding to the above-mentioned substation) and the high-voltage cable, the station end is deployed with a voltage monitoring unit (corresponding to the above-mentioned voltage monitoring module), and each high-voltage cable segment in the underground cable corridor is deployed with a current collection unit ( Figure 4 In the figure, current acquisition unit 1#, current acquisition unit 2#, current acquisition unit 3#, and current acquisition unit 4# are used for schematic illustration, and the current acquisition unit corresponds to the above-mentioned current acquisition module). The voltage monitoring unit and the current acquisition unit synchronize data through an optical fiber communication network (communication can be carried out through the IEC61850 protocol) for online monitoring of power data of the power system.

[0053] Step S102, calculating the first type of phase initial value corresponding to the voltage of the high-voltage cable segment based on the voltage data of the substation, and correcting the first type of phase initial value based on the phase correction model to obtain the first type of phase value corresponding to the voltage of the high-voltage cable segment.

[0054] It should be noted that after collecting the voltage data of the substation, it is necessary to calculate the initial phase value corresponding to the substation voltage based on the substation voltage data to obtain the first type of initial phase value. In order to obtain the phase value corresponding to the voltage of each high-voltage cable segment based on the phase value corresponding to the substation voltage, it is necessary to correct the first type of phase initial value through a pre-constructed phase correction model to obtain the first type of phase value corresponding to the voltage of each high-voltage cable segment.

[0055] It should be noted that the phase correction model in the embodiment of the present invention is a model pre-constructed based on a back propagation neural network and is used to correct the phase value of the voltage of the high-voltage cable segment.

[0056] Optionally, the step of calculating a first type of phase initial value corresponding to the voltage of a high-voltage cable segment based on the voltage data of the substation includes: obtaining a grid frequency and a data sampling frequency, and correcting the grid frequency based on the voltage data of the substation to obtain a corrected grid frequency, wherein the grid frequency represents the frequency of alternating current in the power system, and the data sampling frequency represents the sampling frequency of a data acquisition device when collecting current data of the high-voltage cable segment and voltage data of the substation corresponding to the high-voltage cable segment; calculating the number of sampling points within a sampling cycle based on the data sampling frequency and the corrected grid frequency; calculating the phase value corresponding to the voltage of the substation based on the three-phase voltage values ​​of each sampling point within a sampling cycle and the number of sampling points, and using the phase value corresponding to the voltage of the substation as the first type of phase initial value corresponding to the voltage of the high-voltage cable segment.

[0057] It should be noted that when calculating the voltage phase value of the substation, the grid frequency and data sampling frequency are first obtained. The grid frequency refers to the frequency of fluctuations of the alternating current in the power system in the power network, which is generally a standard value of 50HZ or 60HZ. The data sampling frequency refers to the sampling frequency of data acquisition devices such as the voltage monitoring module and the current acquisition module. In order to ensure the accuracy of the grid frequency, it is necessary to correct the grid frequency to obtain the corrected grid frequency, and then calculate the number of sampling points of the data acquisition device in one sampling period by calculating the ratio of the data sampling frequency to the grid frequency. Then, the phase value corresponding to the voltage of the substation is calculated according to the three-phase voltage values ​​of each sampling point and the number of sampling points, and it is used as the first type of phase initial value corresponding to the voltage of the high-voltage cable segment.

[0058] When calculating the phase value of the voltage, first calculate the number of sampling points in one sampling cycle after correction, that is, f S represents the data sampling frequency, f represents the corrected grid frequency, and determines the voltage value x(n) of each sampling point, where n=1,2...N-1. The voltage value can be the A-phase voltage value. Then, frequency domain transformation is performed to obtain the frequency domain representation of the voltage: Where k is the frequency index representing the different harmonic components and j is the imaginary unit.

[0059] Optionally, the grid frequency is corrected based on the voltage data of the substation to obtain the corrected grid frequency, the steps including: calculating the initial number of sampling points within a sampling cycle based on the grid frequency and the data sampling frequency; selecting two adjacent sampling cycles to obtain a first sampling cycle and a second sampling cycle; calculating a phase value corresponding to the voltage of the substation within the first sampling cycle based on the three-phase voltage values ​​of each sampling point within the first sampling cycle and the initial number of sampling points; calculating a phase value corresponding to the voltage of the substation within the second sampling cycle based on the three-phase voltage values ​​of each sampling point within the second sampling cycle and the initial number of sampling points; correcting the grid frequency based on the phase value corresponding to the voltage of the substation within the first sampling cycle and the phase value corresponding to the voltage of the substation within the second sampling cycle to obtain the corrected grid frequency.

[0060] It should be noted that correcting the grid frequency can ensure the accuracy of the grid frequency, thereby improving the accuracy of subsequent calculation results. Specifically, the number of initial sampling points in a sampling cycle is calculated based on the grid frequency and the data sampling frequency, and the number of sampling points in the entire cycle before correction is N. 0 =(int)(f S ×0.02), where int is the integer of the calculation result, indicating the data sampling frequency, and then two adjacent sampling periods are selected, namely the first sampling period and the second sampling period, and the first sampling period (the first N 0 The phase angle φ 1 , calculate the first sampling period (after N 0 The phase angle φ 2 , then the corrected grid frequency is expressed as: Among them, f 0 is the grid frequency before correction.

[0061] Optionally, the step of correcting the first-type phase initial value based on the phase correction model to obtain the first-type phase value corresponding to the voltage of the high-voltage cable segment includes: obtaining the three-phase current and three-phase power factor of the cable main core to obtain the three-phase current and three-phase power factor of the high-voltage cable segment; obtaining the length of the high-voltage cable segment to be monitored to obtain the cable length value; obtaining the distance value between the first high-voltage cable segment and the substation, wherein the first high-voltage cable segment represents the high-voltage cable segment closest to the substation; inputting the three-phase current, three-phase power factor, cable length value of the high-voltage cable segment and the distance value between the first high-voltage cable segment and the substation into the phase correction model, and outputting the phase correction value corresponding to the voltage of the high-voltage cable segment; correcting the first-type phase initial value based on the phase correction value to obtain the first-type phase value corresponding to the voltage of the high-voltage cable segment.

[0062] It should be noted that the phase correction model can calculate the phase correction value of the voltage of the high-voltage cable segment relative to the substation according to the main core current of the high-voltage cable segment, the phase value corresponding to the main core current, the distance of the high-voltage cable segment from the substation, and the length of the high-voltage cable segment, thereby correcting the first-class phase initial value of each high-voltage cable segment to obtain the first-class phase value of each high-voltage cable segment, thereby improving the accuracy of the insulation status assessment results, and realizing automatic online monitoring while ensuring the accuracy of the monitoring results. Specifically, when correcting the phase, the three-phase current and three-phase power factor of the cable main core are first obtained. The cable main core is the main component responsible for conducting current inside the cable. It is located in the center of the cable and is wrapped by multiple layers of insulating materials and protective layers. The insulation state of the cable will directly affect the size and characteristics of the main core current. For example, aging or damage of the cable insulation material will cause an increase in leakage current. Therefore, when evaluating the insulation state of the high-voltage cable segment, the phase value of the high-voltage cable segment relative to the substation voltage can be corrected by measuring the main core current. At the same time, it is also necessary to obtain the cable length value of the high-voltage cable segment to be monitored and the distance between the high-voltage cable segment and the substation, input the above data into the phase correction model, obtain the mapping relationship between the input data and the phase through the phase correction model, and output the phase correction value of the voltage, so as to add the first-class phase initial value and the phase correction value of the high-voltage cable segment to obtain the first-class phase value corresponding to the voltage of the high-voltage cable segment.

[0063] Optionally, the phase correction model is pre-constructed, and the steps of constructing the phase correction model include: generating a cable simulation model for the high-voltage cable line, and constructing a sample data set based on the cable simulation model, wherein the sample data set includes: the three-phase current and three-phase power factor of the cable main core on the high-voltage cable line, the distance value between the substation and the first high-voltage cable segment, the length value of each high-voltage cable segment on the high-voltage cable line, and the phase correction value corresponding to the voltage of each high-voltage cable segment on the high-voltage cable line; constructing an initial cable correction model based on a back propagation neural network; dividing the sample data set based on a preset division ratio to obtain a training set and a test set; iteratively training the initial cable correction model through the training set to obtain a trained cable correction model; testing the trained cable correction model based on the test set to obtain a test result, and when the test result indicates that the cable correction model passes the test, a trained cable correction model is obtained.

[0064] It should be noted that the phase correction model of the embodiment of the present invention adopts a back propagation neural network and is trained using a back propagation algorithm. The phase correction network includes an input layer, one or more hidden layers, and an output layer. The neurons in each layer are connected to all neurons in the next layer through weights, and are used to correct the voltage phase angle of the high-voltage cable segment to more accurately evaluate the dielectric loss of the high-voltage cable segment. Specifically, when iteratively training the phase correction model, first prepare sample data for training. The sample data is obtained by simulating a simulation model of the high-voltage cable, specifically including the three-phase current and three-phase power factor of the main cable core on the high-voltage cable line, the distance value between the substation and the first high-voltage cable segment, the length value of each high-voltage cable segment on the high-voltage cable line, and the phase correction value corresponding to the voltage of each high-voltage cable segment on the high-voltage cable line. Then, the sample data set is divided, one part is used for iterative training of the model, and the other part is used for performance testing of the model. The iterative training of the model specifically includes the following steps:

[0065] In forward propagation, the input signal is passed from the input layer to the hidden layer, and then to the output layer to calculate the output value. In this process, the signal is weighted and summed through the weights of the network, and then processed by the activation function to generate a new signal to be passed to the next layer.

[0066] Error calculation, compare the output of the network with the actual target value and calculate the loss function.

[0067] Back propagation, propagating the error from the output layer back to the input layer, and adjusting the weights between layers by calculating the gradient. This process uses the chain rule and the gradient descent algorithm to update the weights in the network to reduce the error.

[0068] Weight update, based on the gradient calculated by back-propagation, uses an optimization algorithm to update the weights in the neural network.

[0069] Iterative training repeats the above process of forward propagation, error calculation, back propagation and weight update until the error between the network's predicted output and the actual target value reaches a predetermined threshold, or reaches a preset number of training times.

[0070] Finally, the phase correction model obtained by iterative training is tested through the test set, and the accuracy of the phase correction model is calculated. If the calculated accuracy is greater than the preset accuracy threshold, the model training is determined to be completed.

[0071] Step S103: calculating a second type phase value corresponding to the leakage current of the high-voltage cable segment based on the current data of the high-voltage cable segment.

[0072] Optionally, the step of calculating the second type of phase value corresponding to the leakage current of the high-voltage cable segment based on the current data of the high-voltage cable segment includes: calculating the number of sampling points within a sampling period based on the data sampling frequency and the corrected grid frequency; calculating the leakage current of each sampling point of the high-voltage cable segment within a sampling period based on the input current and output current of each sampling point within a sampling period in the current data of the high-voltage cable segment; calculating the second type of phase value corresponding to the leakage current of the high-voltage cable segment based on the leakage current of each sampling point within a sampling period and the number of sampling points of the high-voltage cable segment.

[0073] It should be noted that after calculating the first type of phase value corresponding to the voltage of the high-voltage cable segment, the phase value corresponding to the current of the high-voltage cable segment is calculated based on the current data of the high-voltage cable segment. The calculation method of the first type of phase value corresponding to the voltage is the same as that of the first type of phase value. First, the number of sampling points in one sampling period after correction is calculated, that is, f S Represents the data sampling frequency, f represents the corrected grid frequency, and determines the leakage current value I(n) of each sampling point, where n=1,2...N-1. The leakage current value is calculated by the input current and output current of the high-voltage cable segment, and then the frequency domain transformation is performed to obtain the frequency domain representation of the voltage: Where k is the frequency index representing the different harmonic components and j is the imaginary unit.

[0074] Step S104, calculating the dielectric loss of the high-voltage cable segment based on the first phase value and the second phase value, determining the insulation state of the main insulation part of the high-voltage cable segment based on the dielectric loss, and generating a status monitoring result of the main insulation of the high-voltage cable based on the insulation state of the main insulation part of the high-voltage cable segment.

[0075] It should be noted that the dielectric loss of the high-voltage cable segment can be calculated based on the corrected first-type phase value and the calculated second-type phase value. The dielectric loss can intuitively reflect the insulation state of the main insulation of the high-voltage cable segment. This is because the dielectric loss is directly related to the properties of the insulating material, especially when the insulating material is aged, damp, contaminated or defective, its dielectric loss characteristics will change significantly. Therefore, the insulation state of the main insulation of the high-voltage cable segment can be evaluated through the dielectric loss of each high-voltage cable segment, and improvement measures can be taken for the main insulation of the high-voltage cable segment according to the specific type of insulation defect.

[0076] Specifically, taking segment A1 as an example, calculate the dielectric loss angle of segment A1: The dielectric loss tan(δ A1 ).tan(δ A1 ) is smaller, indicating that the dielectric loss of section A1 is lower and the insulation performance of section A1 main insulation is better. Conversely, tan(δA1 ) value is larger, indicating that more energy is converted into heat energy in the dielectric, and the insulation performance of the A1 section main insulation is poor.

[0077] Through the above steps, the high-voltage cable section to be monitored is determined, and the current data of the high-voltage cable section and the voltage data of the substation corresponding to the high-voltage cable section are collected, wherein the current data includes the input current and the output current of the high-voltage cable section, the input current represents the current input from the substation to the metal sheath of the high-voltage cable section, the output current refers to the current output from the metal sheath of the high-voltage cable section, and the voltage data represents the three-phase voltage value of the substation, and the first type of phase initial value corresponding to the voltage of the high-voltage cable section is calculated based on the voltage data of the substation, and the first type of phase initial value is corrected based on the phase correction model to obtain the first type of phase value corresponding to the voltage of the high-voltage cable section, wherein the phase correction model is a model pre-constructed based on the back propagation neural network for correcting the phase value of the voltage of the high-voltage cable section, and then the second type of phase value corresponding to the leakage current of the high-voltage cable section is calculated based on the current data of the high-voltage cable section, and finally the dielectric loss of the high-voltage cable section is calculated based on the first type of phase value and the second type of phase value, and the insulation state of the main insulation part of the high-voltage cable section is determined based on the dielectric loss, and the state monitoring result of the main insulation of the high-voltage cable is generated based on the insulation state of the main insulation part of the high-voltage cable section.

[0078] In this embodiment, when evaluating the insulation state of the main insulation of a high-voltage cable segment, current data of the high-voltage cable segment and voltage data of the substation to which the high-voltage cable segment is connected are collected, and an initial phase value of the voltage is calculated based on the voltage data. The initial phase value is corrected by a pre-constructed phase correction model to obtain a phase value corresponding to the voltage of the high-voltage cable segment, and the phase value of the leakage current is calculated by the current data, thereby calculating the dielectric loss of the high-voltage cable segment according to the phase value of the voltage and the phase value of the current, and determining the insulation state of the main insulation part of the high-voltage cable segment through the dielectric loss. The measurement method is simple and suitable for any measurement scenario, achieving the purpose of precise measurement, and achieving the effect of improving the accuracy of the insulation state measurement results, thereby solving the technical problem of low accuracy of the measurement results when measuring the insulation state of the main insulation of the high-voltage cable in the related art.

[0079] The following is a detailed description in conjunction with another embodiment.

[0080] Embodiment 2

[0081] A device for determining the status of the main insulation of a high-voltage cable provided in this embodiment includes multiple implementation units, each implementation unit corresponds to each implementation step in the above-mentioned embodiment 1. Its specific implementation methods and beneficial effects can refer to the above-mentioned method embodiments and will not be repeated here.

[0082] Figure 5is a schematic diagram of an optional device for determining the state of the main insulation of a high-voltage cable according to an embodiment of the present invention, such as Figure 5 As shown, the device for determining the state of the main insulation of the high-voltage cable may include: a collection unit 51, a correction unit 52, a calculation unit 53, and a determination unit 54, wherein:

[0083] The collection unit 51 is used to determine the high-voltage cable segment to be monitored, collect the current data of the high-voltage cable segment and the voltage data of the substation corresponding to the high-voltage cable segment, wherein the current data includes the input current and output current of the high-voltage cable segment, the input current represents the current input from the substation to the metal sheath of the high-voltage cable segment, the output current refers to the current output from the high-voltage cable segment to the metal sheath, and the voltage data represents the three-phase voltage value of the substation;

[0084] A correction unit 52 is used to calculate the first type of phase initial value corresponding to the voltage of the high-voltage cable segment based on the voltage data of the substation, and correct the first type of phase initial value based on the phase correction model to obtain the first type of phase value corresponding to the voltage of the high-voltage cable segment, wherein the phase correction model is a model pre-constructed based on a back propagation neural network for correcting the phase value of the voltage of the high-voltage cable segment;

[0085] A calculation unit 53, configured to calculate a second type of phase value corresponding to a leakage current of the high-voltage cable segment based on current data of the high-voltage cable segment;

[0086] The determination unit 54 is used to calculate the dielectric loss of the high-voltage cable segment based on the first phase value and the second phase value, and determine the insulation state of the main insulation part of the high-voltage cable segment based on the dielectric loss, and generate a status monitoring result of the main insulation of the high-voltage cable based on the insulation state of the main insulation part of the high-voltage cable segment.

[0087] The above-mentioned device for determining the state of the main insulation of the high-voltage cable determines the high-voltage cable section to be monitored through the acquisition unit 51, collects the current data of the high-voltage cable section and the voltage data of the substation corresponding to the high-voltage cable section, wherein the current data includes the input current and output current of the high-voltage cable section, the input current represents the current input from the substation to the metal sheath of the high-voltage cable section, the output current refers to the current output from the high-voltage cable section to the metal sheath, and the voltage data represents the three-phase voltage value of the substation; the correction unit 52 calculates the first-type phase initial value corresponding to the voltage of the high-voltage cable section based on the voltage data of the substation, and corrects the first-type phase initial value based on the phase correction model. The initial phase value is corrected to obtain a first type of phase value corresponding to the voltage of the high-voltage cable segment, wherein the phase correction model is a model pre-constructed based on the back propagation neural network for correcting the phase value of the voltage of the high-voltage cable segment; the second type of phase value corresponding to the leakage current of the high-voltage cable segment is calculated based on the current data of the high-voltage cable segment by the calculation unit 53; the dielectric loss of the high-voltage cable segment is calculated based on the first type of phase value and the second type of phase value by the determination unit 54, and the insulation state of the main insulation part of the high-voltage cable segment is determined based on the dielectric loss, and the status monitoring result of the main insulation of the high-voltage cable is generated based on the insulation state of the main insulation part of the high-voltage cable segment.

[0088] In this embodiment, when evaluating the insulation state of the main insulation of a high-voltage cable segment, current data of the high-voltage cable segment and voltage data of the substation to which the high-voltage cable segment is connected are collected, and an initial phase value of the voltage is calculated based on the voltage data. The initial phase value is corrected by a pre-constructed phase correction model to obtain a phase value corresponding to the voltage of the high-voltage cable segment, and the phase value of the leakage current is calculated by the current data, thereby calculating the dielectric loss of the high-voltage cable segment according to the phase value of the voltage and the phase value of the current, and determining the insulation state of the main insulation part of the high-voltage cable segment through the dielectric loss. The measurement method is simple and suitable for any measurement scenario, achieving the purpose of precise measurement, and achieving the effect of improving the accuracy of the insulation state measurement results, thereby solving the technical problem of low accuracy of the measurement results when measuring the insulation state of the main insulation of the high-voltage cable in the related art.

[0089] Optionally, the correction unit includes: a first correction module, used to obtain the grid frequency and the data sampling frequency, and correct the grid frequency based on the voltage data of the substation to obtain a corrected grid frequency, wherein the grid frequency represents the frequency of the alternating current in the power system, and the data sampling frequency represents the sampling frequency of the data acquisition device when collecting the current data of the high-voltage cable segment and the voltage data of the substation corresponding to the high-voltage cable segment; a first calculation module, used to calculate the number of sampling points within a sampling cycle based on the data sampling frequency and the corrected grid frequency; a second calculation module, used to calculate the phase value corresponding to the voltage of the substation based on the three-phase voltage values ​​of each sampling point within a sampling cycle and the number of sampling points, and use the phase value corresponding to the voltage of the substation as the first type of phase initial value corresponding to the voltage of the high-voltage cable segment.

[0090] Optionally, the first correction module includes: a first calculation submodule, which is used to calculate the initial number of sampling points within a sampling cycle based on the grid frequency and the data sampling frequency; a first selection submodule, which is used to select two adjacent sampling cycles to obtain a first sampling cycle and a second sampling cycle; a second calculation submodule, which is used to calculate the phase value corresponding to the voltage of the substation within the first sampling cycle based on the three-phase voltage values ​​of each sampling point within the first sampling cycle and the initial number of sampling points; a third calculation submodule, which is used to calculate the phase value corresponding to the voltage of the substation within the second sampling cycle based on the three-phase voltage values ​​of each sampling point within the second sampling cycle and the initial number of sampling points; the first correction submodule, which is used to correct the grid frequency based on the phase value corresponding to the voltage of the substation within the first sampling cycle and the phase value corresponding to the voltage of the substation within the second sampling cycle to obtain a corrected grid frequency.

[0091] Optionally, the correction unit includes: a first acquisition module, used to acquire the three-phase current and three-phase power factor of the cable main core, and obtain the three-phase current and three-phase power factor of the high-voltage cable segment; a second acquisition module, used to acquire the length of the high-voltage cable segment to be monitored, and obtain the cable length value; a third acquisition module, used to acquire the distance value between the first high-voltage cable segment and the substation, wherein the first high-voltage cable segment represents the high-voltage cable segment closest to the substation; a first output module, used to input the three-phase current, three-phase power factor, cable length value of the high-voltage cable segment, and the distance value between the first high-voltage cable segment and the substation into the phase correction model, and output the phase correction value corresponding to the voltage of the high-voltage cable segment; a second correction module, used to correct the first type of phase initial value based on the phase correction value, and obtain the first type of phase value corresponding to the voltage of the high-voltage cable segment.

[0092] Optionally, the calculation unit includes: a third calculation module, used to calculate the number of sampling points within a sampling cycle based on the data sampling frequency and the corrected grid frequency; a fourth calculation module, used to calculate the leakage current of each sampling point of the high-voltage cable segment within a sampling cycle based on the input current and output current of each sampling point within a sampling cycle in the current data of the high-voltage cable segment; a fifth calculation module, used to calculate the second type phase value corresponding to the leakage current of the high-voltage cable segment based on the leakage current of each sampling point within a sampling cycle and the number of sampling points of the high-voltage cable segment.

[0093] Optionally, the state determination device for the main insulation of a high-voltage cable also includes: a first construction module, which is used to generate a cable simulation model for a high-voltage cable line, and construct a sample data set based on the cable simulation model, wherein the sample data set includes: the three-phase current and three-phase power factor of the main cable core on the high-voltage cable line, the distance value between the substation and the first high-voltage cable segment, the length value of each high-voltage cable segment on the high-voltage cable line, and the phase correction value corresponding to the voltage of each high-voltage cable segment on the high-voltage cable line; a second construction module, which is used to construct an initial cable correction model based on a back propagation neural network; a first division module, which is used to divide the sample data set based on a preset division ratio to obtain a training set and a test set; a first training module, which is used to iteratively train the initial cable correction model through the training set to obtain a trained cable correction model; a first testing module, which is used to test the trained cable correction model based on the test set to obtain a test result, and when the test result indicates that the cable correction model passes the test, a trained cable correction model is obtained.

[0094] Optionally, the device for determining the status of the main insulation of a high-voltage cable also includes: a first configuration module, used to configure a voltage monitoring module for the substation; a second configuration module, used to configure a current acquisition module for the high-voltage cable segment; a first connection module, used to construct a fiber-optic communication network, and connect the voltage monitoring module and the current acquisition module based on the fiber-optic communication network.

[0095] The above-mentioned high-voltage cable main insulation status determination device may also include a processor and a memory. The above-mentioned acquisition unit 51, correction unit 52, calculation unit 53, determination unit 54, etc. are all stored in the memory as program units, and the processor executes the above-mentioned program units stored in the memory to realize corresponding functions.

[0096] The processor includes a kernel, which retrieves the corresponding program unit from the memory. One or more kernels can be set, and the working state of the main insulation of the high-voltage cable can be obtained by adjusting the kernel parameters.

[0097] The above-mentioned memory may include non-permanent memory in a computer-readable medium, random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM, and the memory includes at least one storage chip.

[0098] According to another aspect of an embodiment of the present invention, a computer-readable storage medium is also provided, the computer-readable storage medium including a stored computer program, wherein when the computer program is running, the device where the computer-readable storage medium is located is controlled to execute any of the above-mentioned methods for determining the status of the main insulation of a high-voltage cable.

[0099] According to another aspect of an embodiment of the present invention, there is also provided an electronic device, comprising one or more processors and a memory, the memory being used to store one or more programs, wherein when the one or more programs are executed by one or more processors, the one or more processors implement any one of the above-mentioned methods for determining the status of the main insulation of a high-voltage cable.

[0100] According to another aspect of an embodiment of the present invention, a computer program product is further provided. The computer program product includes a computer program, wherein when the computer program is executed by a processor, any one of the above-mentioned methods for determining the state of the main insulation of a high-voltage cable is implemented.

[0101] The present application also provides a computer program product, which, when executed on a data processing device, is suitable for executing an initialization program having the following method steps: determining a high-voltage cable segment to be monitored, collecting current data of the high-voltage cable segment and voltage data of a substation corresponding to the high-voltage cable segment, wherein the current data includes an input current and an output current of the high-voltage cable segment, the input current represents the current input from the substation to the metal sheath of the high-voltage cable segment, the output current refers to the current output from the high-voltage cable segment to the metal sheath, and the voltage data represents the three-phase voltage value of the substation; based on the voltage data of the substation, the first-type phase initialization corresponding to the voltage of the high-voltage cable segment is calculated; value, and correct the first type of phase initial value based on the phase correction model to obtain the first type of phase value corresponding to the voltage of the high-voltage cable segment, wherein the phase correction model is a model pre-constructed based on the back propagation neural network for correcting the phase value of the voltage of the high-voltage cable segment; the second type of phase value corresponding to the leakage current of the high-voltage cable segment is calculated based on the current data of the high-voltage cable segment; the dielectric loss of the high-voltage cable segment is calculated based on the first type of phase value and the second type of phase value, and the insulation state of the main insulation part of the high-voltage cable segment is determined based on the dielectric loss, and the state monitoring result of the main insulation of the high-voltage cable is generated based on the insulation state of the main insulation part of the high-voltage cable segment.

[0102] The present application also provides a computer program product, which, when executed on a data processing device, is also suitable for executing a program that is initialized with the following method steps: the step of calculating a first-type phase initial value corresponding to the voltage of a high-voltage cable segment based on the voltage data of the substation includes: obtaining a grid frequency and a data sampling frequency, and correcting the grid frequency based on the voltage data of the substation to obtain a corrected grid frequency, wherein the grid frequency represents the frequency of alternating current in the power system, and the data sampling frequency represents the sampling frequency of the data acquisition device when collecting current data of the high-voltage cable segment and voltage data of the substation corresponding to the high-voltage cable segment; calculating the number of sampling points within a sampling cycle based on the data sampling frequency and the corrected grid frequency; calculating the phase value corresponding to the voltage of the substation based on the three-phase voltage values ​​of each sampling point within a sampling cycle and the number of sampling points, and using the phase value corresponding to the voltage of the substation as the first-type phase initial value corresponding to the voltage of the high-voltage cable segment.

[0103] The present application also provides a computer program product, which, when executed on a data processing device, is also suitable for executing a program that is initialized with the following method steps: the grid frequency is corrected based on the voltage data of the substation, and the step of obtaining the corrected grid frequency includes: calculating the initial number of sampling points in a sampling period based on the grid frequency and the data sampling frequency; selecting two adjacent sampling periods to obtain a first sampling period and a second sampling period; calculating the phase value corresponding to the voltage of the substation in the first sampling period based on the three-phase voltage values ​​of each sampling point in the first sampling period and the initial number of sampling points; calculating the phase value corresponding to the voltage of the substation in the second sampling period based on the three-phase voltage values ​​of each sampling point in the second sampling period and the initial number of sampling points; correcting the grid frequency based on the phase value corresponding to the voltage of the substation in the first sampling period and the phase value corresponding to the voltage of the substation in the second sampling period to obtain the corrected grid frequency.

[0104] The present application also provides a computer program product, which, when executed on a data processing device, is also suitable for executing a program that is initialized with the following method steps: correcting the first-type phase initial value based on the phase correction model, and obtaining the first-type phase value corresponding to the voltage of the high-voltage cable segment. The step includes: obtaining the three-phase current and three-phase power factor of the cable main core to obtain the three-phase current and three-phase power factor of the high-voltage cable segment; obtaining the length of the high-voltage cable segment to be monitored to obtain the cable length value; obtaining the distance value between the first high-voltage cable segment and the substation, wherein the first high-voltage cable segment represents the high-voltage cable segment closest to the substation; inputting the three-phase current, three-phase power factor, cable length value of the high-voltage cable segment and the distance value between the first high-voltage cable segment and the substation into the phase correction model, and outputting the phase correction value corresponding to the voltage of the high-voltage cable segment; correcting the first-type phase initial value based on the phase correction value to obtain the first-type phase value corresponding to the voltage of the high-voltage cable segment.

[0105] The present application also provides a computer program product, which, when executed on a data processing device, is also suitable for executing a program that is initialized with the following method steps: the step of calculating a second type of phase value corresponding to the leakage current of the high-voltage cable segment based on the current data of the high-voltage cable segment includes: calculating the number of sampling points within a sampling period based on the data sampling frequency and the corrected grid frequency; calculating the leakage current of each sampling point of the high-voltage cable segment within a sampling period based on the input current and output current of each sampling point in the current data of the high-voltage cable segment within a sampling period; calculating the second type of phase value corresponding to the leakage current of the high-voltage cable segment based on the leakage current of each sampling point of the high-voltage cable segment within a sampling period and the number of sampling points.

[0106] The present application also provides a computer program product, which, when executed on a data processing device, is also suitable for executing a program that is initialized with the following method steps: a phase correction model is pre-constructed, and the step of constructing the phase correction model includes: generating a cable simulation model for a high-voltage cable line, and constructing a sample data set based on the cable simulation model, wherein the sample data set includes: three-phase current and three-phase power factor of a cable main core on the high-voltage cable line, a distance value between a substation and a first high-voltage cable segment, a length value of each high-voltage cable segment on the high-voltage cable line, and a phase correction value corresponding to the voltage of each high-voltage cable segment on the high-voltage cable line; constructing an initial cable correction model based on a back propagation neural network; dividing the sample data set based on a preset division ratio to obtain a training set and a test set; iteratively training the initial cable correction model through the training set to obtain a trained cable correction model; testing the trained cable correction model based on the test set to obtain a test result, and when the test result indicates that the cable correction model passes the test, a trained cable correction model is obtained.

[0107] The present application also provides a computer program product, which, when executed on a data processing device, is also suitable for executing a program that initializes the following method steps: before determining the high-voltage cable segment to be monitored, it also includes: configuring a voltage monitoring module for the substation; configuring a current acquisition module for the high-voltage cable segment; building a fiber-optic communication network, and connecting the voltage monitoring module and the current acquisition module based on the fiber-optic communication network.

[0108] Figure 6 1 is a hardware structure block diagram of an electronic device (or mobile device) for determining the state of the main insulation of a high-voltage cable according to an embodiment of the present invention. Figure 6 As shown, the electronic device may include one or more processors ( Figure 6602a, 602b, ..., 602n are used to illustrate), a memory 604 for storing data. In addition, it may also include: a display, an input / output interface (I / O interface), a universal serial bus (USB) port (which may be included as one of the ports of the I / O interface), a network interface, a keyboard, a power supply and / or a camera. It can be understood by those skilled in the art that Figure 6 The structure shown is only for illustration and does not limit the structure of the above electronic device. Figure 6 More or fewer components as shown, or with Figure 6 Different configurations shown.

[0109] The serial numbers of the above embodiments of the present invention are only for description and do not represent the advantages or disadvantages of the embodiments.

[0110] In the above embodiments of the present invention, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0111] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. Among them, the device embodiments described above are only schematic. For example, the division of units can be a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of units or modules, which can be electrical or other forms.

[0112] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed over multiple units. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0113] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0114] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for a computer device (which can be a personal computer, a server or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), mobile hard disk, magnetic disk or optical disk and other media that can store program codes.

[0115] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for determining the state of the main insulation of a high-voltage cable, characterized in that: include: Determine a high-voltage cable segment to be monitored, collect current data of the high-voltage cable segment and voltage data of a substation corresponding to the high-voltage cable segment, wherein the current data includes input current and output current of the high-voltage cable segment, the input current represents the current input from the substation to the metal sheath of the high-voltage cable segment, the output current refers to the current output from the high-voltage cable segment to the metal sheath, and the voltage data represents the three-phase voltage value of the substation; Calculating a first type of phase initial value corresponding to the voltage of the high-voltage cable segment based on the voltage data of the substation, and correcting the first type of phase initial value based on a phase correction model to obtain a first type of phase value corresponding to the voltage of the high-voltage cable segment, wherein the phase correction model is a model pre-constructed based on a back propagation neural network for correcting the phase value of the voltage of the high-voltage cable segment; Calculating a second type of phase value corresponding to the leakage current of the high-voltage cable segment based on the current data of the high-voltage cable segment; The dielectric loss of the high-voltage cable segment is calculated based on the first type of phase value and the second type of phase value, and the insulation state of the main insulation part of the high-voltage cable segment is determined based on the dielectric loss, and the state monitoring result of the main insulation of the high-voltage cable is generated based on the insulation state of the main insulation part of the high-voltage cable segment.

2. The determination method according to claim 1, characterized in that: The step of calculating the first type of phase initial value corresponding to the voltage of the high-voltage cable section based on the voltage data of the substation comprises: Acquire a grid frequency and a data sampling frequency, and correct the grid frequency based on the voltage data of the substation to obtain the corrected grid frequency, wherein the grid frequency represents the frequency of alternating current in the power system, and the data sampling frequency represents the sampling frequency of a data acquisition device when collecting current data of the high-voltage cable segment and voltage data of the substation corresponding to the high-voltage cable segment; Calculate the number of sampling points within a sampling period based on the data sampling frequency and the corrected power grid frequency; The phase value corresponding to the voltage of the substation is calculated based on the three-phase voltage values ​​of each sampling point in a sampling period and the number of sampling points, and the phase value corresponding to the voltage of the substation is used as the first type phase initial value corresponding to the voltage of the high-voltage cable segment.

3. The determination method according to claim 2, characterized in that: The step of correcting the grid frequency based on the voltage data of the substation to obtain the corrected grid frequency includes: Calculate the number of initial sampling points within a sampling period based on the power grid frequency and the data sampling frequency; Selecting two adjacent sampling periods to obtain a first sampling period and a second sampling period; Calculate the phase value corresponding to the voltage of the substation in the first sampling period based on the three-phase voltage values ​​of each sampling point in the first sampling period and the initial number of sampling points; Calculate the phase value corresponding to the voltage of the substation in the second sampling period based on the three-phase voltage values ​​of each sampling point in the second sampling period and the number of the initial sampling points; The grid frequency is corrected based on a phase value corresponding to the voltage of the substation in the first sampling period and a phase value corresponding to the voltage of the substation in the second sampling period to obtain a corrected grid frequency.

4. The determination method according to claim 1, characterized in that: The step of correcting the first type of phase initial value based on the phase correction model to obtain the first type of phase value corresponding to the voltage of the high-voltage cable segment includes: Obtaining the three-phase current and three-phase power factor of the cable main core, and obtaining the three-phase current and three-phase power factor of the high-voltage cable section; Obtaining the length of the high-voltage cable segment to be monitored to obtain a cable length value; Acquire a distance value between a first high-voltage cable segment and the substation, wherein the first high-voltage cable segment represents a high-voltage cable segment closest to the substation; Input the three-phase current of the high-voltage cable segment, the three-phase power factor, the cable length value, and the distance value between the first high-voltage cable segment and the substation into the phase correction model, and output a phase correction value corresponding to the voltage of the high-voltage cable segment; The first type of phase initial value is corrected based on the phase correction value to obtain a first type of phase value corresponding to the voltage of the high-voltage cable segment.

5. The determination method according to claim 2, characterized in that: The step of calculating the second type phase value corresponding to the leakage current of the high-voltage cable segment based on the current data of the high-voltage cable segment comprises: Calculate the number of sampling points within a sampling period based on the data sampling frequency and the corrected power grid frequency; Calculate the leakage current of each sampling point of the high-voltage cable segment within a sampling period based on the input current and output current of each sampling point within a sampling period in the current data of the high-voltage cable segment; The second type phase value corresponding to the leakage current of the high-voltage cable segment is calculated based on the leakage current of each sampling point of the high-voltage cable segment within a sampling period and the number of the sampling points.

6. The determination method according to claim 1, characterized in that: The phase correction model is pre-constructed, and the steps of constructing the phase correction model include: Generate a cable simulation model for the high-voltage cable line, and construct a sample data set based on the cable simulation model, wherein the sample data set includes: three-phase current and three-phase power factor of the main cable core on the high-voltage cable line, the distance value between the substation and the first high-voltage cable segment, the length value of each high-voltage cable segment on the high-voltage cable line, and the phase correction value corresponding to the voltage of each high-voltage cable segment on the high-voltage cable line; constructing an initial cable correction model based on the back propagation neural network; Dividing the sample data set based on a preset division ratio to obtain a training set and a test set; Iteratively training the initial cable correction model using the training set to obtain the trained cable correction model; The trained cable correction model is tested based on the test set to obtain a test result. When the test result indicates that the cable correction model passes the test, the trained cable correction model is obtained.

7. The determination method according to claim 1, characterized in that: Before determining the high voltage cable section to be monitored, also include: Configuring a voltage monitoring module for the substation; Configuring a current acquisition module for the high-voltage cable segment; An optical fiber communication network is constructed, and the voltage monitoring module and the current acquisition module are connected based on the optical fiber communication network.

8. A device for determining the state of the main insulation of a high-voltage cable, characterized in that: include: A collection unit, used to determine a high-voltage cable segment to be monitored, collect current data of the high-voltage cable segment and voltage data of a substation corresponding to the high-voltage cable segment, wherein the current data includes an input current and an output current of the high-voltage cable segment, the input current represents a current input from the substation to a metal sheath of the high-voltage cable segment, the output current refers to a current output from the high-voltage cable segment to the metal sheath, and the voltage data represents a three-phase voltage value of the substation; A correction unit, configured to calculate a first type of phase initial value corresponding to the voltage of the high-voltage cable segment based on the voltage data of the substation, and to correct the first type of phase initial value based on a phase correction model to obtain a first type of phase value corresponding to the voltage of the high-voltage cable segment, wherein the phase correction model is a model pre-constructed based on a back propagation neural network for correcting the phase value of the voltage of the high-voltage cable segment; A calculation unit, configured to calculate a second type of phase value corresponding to a leakage current of the high-voltage cable segment based on current data of the high-voltage cable segment; A determination unit is used to calculate the dielectric loss of the high-voltage cable segment based on the first phase value and the second phase value, and determine the insulation state of the main insulation part of the high-voltage cable segment based on the dielectric loss, and generate a status monitoring result of the main insulation of the high-voltage cable based on the insulation state of the main insulation part of the high-voltage cable segment.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium includes a stored computer program, wherein when the computer program is executed, the device where the computer-readable storage medium is located is controlled to execute the method for determining the state of the main insulation of a high-voltage cable according to any one of claims 1 to 7.

10. An electronic device, characterized in that: It comprises one or more processors and a memory, wherein the memory is used to store one or more programs, wherein when the one or more programs are executed by the one or more processors, the one or more processors implement the method for determining the state of the main insulation of a high-voltage cable as described in any one of claims 1 to 7.

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