Method and device for determining the condition of the main insulation of a high voltage cable, electronic device

Abstract

The application discloses a kind of high-voltage cable main insulation state determination method and device, electronic equipment, it is related to power grid safety field or other related technical fields, the method comprises: the current data of high-voltage cable section and the voltage data of the corresponding transformer substation of high-voltage cable section are collected;Voltage data is based on the calculation of the voltage corresponding first type phase initial value of high-voltage cable section, and the first type phase initial value is corrected, and the voltage corresponding first type phase value of high-voltage cable section is obtained;Leakage current corresponding second type phase value of high-voltage cable section is calculated based on current data;Based on first type phase value and second type phase value, the dielectric loss of high-voltage cable section is calculated, and the insulation state of the main insulation part of high-voltage cable section is determined, and the state monitoring result of high-voltage cable main insulation is generated based on insulation state.The application solves the technical problem that measurement result accuracy is relatively low in related art when measuring the insulation state of high-voltage cable main insulation.

Description

TECHNICAL FIELD

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

[0002] With the development of the power industry, power cables play an increasingly important role in power systems. Due to the widespread use of power cables, the safe operation of power cables is particularly important, and the insulation performance of the main insulation part of the power cable is crucial to the safe operation of the power cable.

[0003] In related technologies, methods for determining the insulation state of the main insulation include the relative permittivity method, the angle difference method based on the voltage at both ends of the cable, and the interphase relative method, etc. Among them, the relative permittivity method monitors the leakage current of the main insulation of the high-voltage cable segment online, calculates the capacitance using the formula , and then calculates the relative permittivity of the cross-connection small section. According to the change of the relative permittivity of the cross-connection small section, the insulation state of the main insulation is determined. This insulation state monitoring method based on relative permittivity 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 ends with outlets. The voltage U1, U2 and current I1, I2 at both ends of the high-voltage cable can be measured synchronously using GPS or Beidou synchronization technology, and then U I , the angle difference is calculated, and the insulation state of the cable main insulation is evaluated. This measurement method is only applicable to special structure high-voltage cable lines and does not have universality, and has low measurement accuracy and low measurement result accuracy. The interphase relative method uses the relative phase difference of the interphase current to evaluate the insulation state of the cable segment in the cross-connection cable system. This relative calculation method has low measurement result accuracy.

[0004] In summary, the state measurement method of the main insulation of the high-voltage cable in related technologies has high measurement requirements, does not have universality, and has low measurement result accuracy.

[0005] To address the above problems, no effective solutions have been proposed so far. SUMMARY

[0006] Embodiments of the present application provide a method and device for determining the state of the main insulation of a high-voltage cable, and an electronic device, to at least solve the technical problem of low measurement result accuracy when measuring the insulation state of the main insulation of a high-voltage cable in related technologies. ​​​​​

[0007] According to an aspect of the embodiments of the present application, a method for determining the state of the main insulation of a high-voltage cable is provided, which comprises: 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 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, and the voltage data represents three-phase voltage values 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 for correcting the phase value of the voltage of the high-voltage cable segment, which is constructed in advance based on a back propagation neural network; 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; calculating 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 determining the insulation state of the main insulation part of the high-voltage cable segment based on the dielectric loss, and generating a state 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.

[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 comprises: obtaining a power grid frequency and a data sampling frequency, and correcting the power grid frequency based on the voltage data of the substation to obtain a corrected power grid frequency, wherein the power grid frequency represents the frequency of alternating current in a power system, and the data sampling frequency represents the sampling frequency of a 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 in one sampling period based on the data sampling frequency and the corrected power grid frequency; calculating the phase value corresponding to the voltage of the substation based on the three-phase voltage values of each sampling point in one sampling period and the number of sampling points, and taking 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 step of correcting the power grid frequency based on the voltage data of the transformer substation to obtain a corrected power grid frequency comprises: calculating an initial sampling point number in 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; calculating a phase value corresponding to the voltage of the transformer 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 sampling point number; calculating a phase value corresponding to the voltage of the transformer 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 sampling point number; correcting the power grid frequency based on the phase value corresponding to the voltage of the transformer substation in the first sampling period and the phase value corresponding to the voltage of the transformer substation in the second sampling period to obtain a corrected power grid frequency.

[0010] Optionally, the step of 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 section comprises: obtaining three-phase currents and three-phase power factors of a cable main core to obtain three-phase currents and three-phase power factors of the high-voltage cable section; obtaining a cable length value of the high-voltage cable section to be monitored; obtaining a distance value between a first high-voltage cable section and the transformer substation, wherein the first high-voltage cable section represents the high-voltage cable section closest to the transformer substation; inputting the three-phase currents, the three-phase power factors, the cable length value, and the distance value between the first high-voltage cable section and the transformer substation into the phase correction model to output a phase correction value corresponding to the voltage of the high-voltage cable section; correcting the first type of phase initial value based on the phase correction value to obtain a first type of phase value corresponding to the voltage of the high-voltage cable section.

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

[0012] Optionally, the phase correction model is pre-constructed, and the step of constructing the phase correction model comprises: 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 comprises: three-phase currents and three-phase power factors of a cable main core on the high-voltage cable line, a distance value of the substation from a first high-voltage cable segment, length values of each high-voltage cable segment on the high-voltage cable line, and phase correction values corresponding to voltages 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 based on 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 obtaining the trained cable correction model in a case where the test result indicates that the cable correction model passes the test.

[0013] Optionally, before determining the high-voltage cable segment to be monitored, the method further comprises: configuring a voltage monitoring module for the substation; configuring a current collection module for the high-voltage cable segment; constructing an optical fiber communication network, and connecting the voltage monitoring module and the current collection module based on the optical fiber communication network.

[0014] According to another aspect of the embodiment of the present application, a state determination apparatus for a high-voltage cable main insulation is also provided, comprising: an acquisition unit configured to determine a high-voltage cable segment to be monitored, and acquire 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 input current and output current of the high-voltage cable segment, the input current represents current input from the substation to a metal sheath of the high-voltage cable segment, the output current refers to current output from the metal sheath of the high-voltage cable segment, and the voltage data represents three-phase voltage values of the substation; a correction unit configured to calculate first-type phase initial values corresponding to voltages of the high-voltage cable segment based on the voltage data of the substation, and correct the first-type phase initial values based on a phase correction model to obtain first-type phase values corresponding to the voltages 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 phase values of the voltages of the high-voltage cable segment; a calculation unit configured to calculate second-type phase values corresponding to leakage currents of the high-voltage cable segment based on the current data of the high-voltage cable segment; and a determination unit configured to calculate dielectric loss of the high-voltage cable segment based on the first-type phase values and the second-type phase values, determine an insulation state of a main insulation part of the high-voltage cable segment based on the dielectric loss, and generate a state monitoring result of the high-voltage cable main insulation 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 period 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 period 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 period based on the grid frequency and the data sampling frequency; a first selection submodule, used to select two adjacent sampling periods to obtain a first sampling period and a second sampling period; a second calculation submodule, used to calculate the phase value corresponding to the voltage of the substation within the first sampling period based on the three-phase voltage values ​​of each sampling point within the first sampling period 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 period based on the three-phase voltage values ​​of each sampling point within the second sampling period and the initial number of sampling points; and a 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 period and the phase value corresponding to the voltage of the substation within the second sampling period to obtain the corrected grid frequency.

[0017] Optionally, the correction unit comprises: a first obtaining module, configured to obtain three-phase currents and three-phase power factors of the cable main core, to obtain three-phase currents and three-phase power factors of the high-voltage cable section; a second obtaining module, configured to obtain a length of the high-voltage cable section to be monitored, to obtain a cable length value; a third obtaining module, configured to obtain a distance value between a first high-voltage cable section and the transformer substation, wherein the first high-voltage cable section represents a high-voltage cable section closest to the transformer substation; a first output module, configured to input the three-phase currents, the three-phase power factors, the cable length value, and the distance value between the first high-voltage cable section and the transformer substation of the high-voltage cable section into the phase correction model, and output a phase correction value corresponding to a voltage of the high-voltage cable section; and a second correction module, configured to correct the first type of phase initial value based on the phase correction value, to obtain a first type of phase value corresponding to the voltage of the high-voltage cable section.

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

[0019] Optionally, the high-voltage cable main insulation state determination apparatus further comprises: a first construction module, configured to generate a cable simulation model for a high-voltage cable line, and to construct a sample data set based on the cable simulation model, wherein the sample data set comprises: three-phase currents and three-phase power factors of a cable main core on the high-voltage cable line, a distance value between the transformer substation and a first high-voltage cable section, length values of each high-voltage cable section on the high-voltage cable line, and phase correction values corresponding to voltages of each high-voltage cable section on the high-voltage cable line; a second construction module, configured to construct an initial cable correction model based on the back propagation neural network; a first division module, configured 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, configured to iteratively train the initial cable correction model through the training set, to obtain a trained cable correction model; and a first test module, configured to test the trained cable correction model based on the test set, to obtain a test result, and to obtain the trained cable correction model in a case where the test result indicates that the cable correction model passes the test.

[0020] Optionally, the state determination apparatus of the high-voltage cable main insulation further comprises: a first configuration module configured to configure a voltage monitoring module for the substation; a second configuration module configured to configure a current collection module for the high-voltage cable segment; and a first connection module configured to construct an optical fiber communication network and connect the voltage monitoring module and the current collection module based on the optical fiber communication network.

[0021] According to another aspect of the embodiments of the present application, a computer readable storage medium is also provided, which comprises a stored computer program, wherein the computer readable storage medium controls a device where the computer readable storage medium is located to perform any of the above-mentioned state determination methods of high-voltage cable main insulation when the computer program is running.

[0022] According to another aspect of the embodiments of the present application, an electronic device is also provided, which comprises one or more processors and a memory, and the memory is configured to store one or more programs, wherein the one or more programs, when executed by the one or more processors, cause the one or more processors to implement any of the above-mentioned state determination methods of high-voltage cable main insulation.

[0023] In the present application, by the following 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 comprises input current and output current of the high-voltage cable segment, the input current represents current input from the substation to the metal sheath of the high-voltage cable segment, and the output current refers to current output from the metal sheath of the high-voltage cable segment, and the voltage data represents three-phase voltage values of the substation, calculating a first type of phase initial value corresponding to 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 for correcting the phase value of the voltage of the high-voltage cable segment, which is constructed in advance based on a back propagation neural network, then calculating a second type of phase value corresponding to leakage current of the high-voltage cable segment based on the current data of the high-voltage cable segment, and finally calculating dielectric loss of the high-voltage cable segment based on the first type of phase value and the second type of phase value, and determining an insulation state of a main insulation part of the high-voltage cable segment based on the dielectric loss, and generating a state monitoring result of the high-voltage cable main insulation 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 the high-voltage cable section, the current data of the high-voltage cable section and the voltage data of the transformer substation connected with the high-voltage cable section are collected, the initial phase value of the voltage is calculated based on the voltage data, the initial phase value is corrected through the pre-constructed phase correction model to obtain the phase value corresponding to the voltage of the high-voltage cable section, and the phase value of the leakage current is calculated through the current data, so as to calculate the dielectric loss of the high-voltage cable section according to the phase value of the voltage and the phase value of the current, determine the insulation state of the main insulation part of the high-voltage cable section through the dielectric loss, the measurement method is simple, suitable for any measurement scene, and the purpose of accurate measurement is achieved, the effect of improving the accuracy of the insulation state measurement result is achieved, and the technical problem of low measurement result accuracy in the related art when measuring the insulation state of the main insulation of the high-voltage cable is solved. BRIEF DESCRIPTION OF DRAWINGS

[0025] The accompanying drawings, which are included to provide a further understanding of the application and constitute a part of this application, illustrate embodiments of the application and together with the description serve to explain the application. In the drawings:

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

[0027] Figure 2 is a schematic diagram of an optional cross-interconnected part of the high-voltage cable according to an embodiment of the application;

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

[0029] Figure 4 is a schematic diagram of an optional high-voltage cable section measurement device according to an embodiment of the application;

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

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

[0032] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions 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 embodiments described 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 making creative efforts should fall within the scope of protection of the present invention.

[0033] It should be noted that the terms "first", "second", etc. in the description 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 numbers 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 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 status 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 security when the working status of the main insulation of a 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 security when the working status of the main insulation of a high-voltage cable is determined based on the dielectric loss of the high-voltage cable segment. The application does not limit the application field of the method for determining the status of the main insulation of a 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 morals, and provide corresponding operation entrances for users to choose to authorize or refuse. For example, an interface is set up between this system and the relevant users or institutions. Before obtaining relevant information, it is necessary to send an acquisition request to the aforementioned user or institution through the interface, and obtain the relevant information after receiving the consent information fed back by the aforementioned user or institution.

[0036] It should be noted that in the present application, when collecting and analyzing customer information, a corresponding operation portal is provided for the user to select to agree or refuse the automatic decision result; if the user chooses to refuse, the expert decision process is entered.

[0037] The following embodiments of the present application can be applied to various high-voltage cable main insulation state determination systems / applications / devices. The present application collects current data of a high-voltage cable section and voltage data of a substation in real time through an online monitoring device of the high-voltage cable section, the measurement method is simple, suitable for general measurement environment, and each module in the device can synchronize data through an optical fiber communication network, realizing high-precision data synchronization in harsh environments, which helps to improve the accuracy of state measurement. At the same time, the present application calculates the phase value of the substation voltage based on the voltage data, and corrects the phase value of the substation voltage, so as to obtain the phase value of the high-voltage cable section voltage, and calculates the phase value of the high-voltage cable section leakage current based on the current data, and then calculates the dielectric loss of the high-voltage cable section according to the phase value of the voltage and the phase value of the leakage current, so as to determine the insulation state of the high-voltage cable section main insulation, and realize accurate measurement of the insulation state, and guarantee the accuracy of the measurement result.

[0038] The present application will be described in detail below in conjunction with various embodiments.

[0039] Embodiment one

[0040] According to the embodiments of the present application, an embodiment of a high-voltage cable main insulation state determination method 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 the logical order is shown in the flowchart, in some cases, the steps shown or described herein can be executed in an order different from that shown herein.

[0041] Figure 1 is a flowchart of an optional high-voltage cable main insulation state determination method according to the embodiments of the present application, as shown in Figure 1 The method comprises the following steps:

[0042] Step S101, determine the high-voltage cable section to be monitored, collect the current data of the high-voltage cable section and the voltage data of the corresponding substation of the high-voltage cable section.

[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-consuming 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 primary insulation of a high-voltage cable is the critical insulating layer located between the cable conductor (the metal wire through which current flows) and the grounded shield (or metal sheath). The primary insulation's primary function is to provide electrical isolation, ensuring that current flows only within the conductor and does not leak into the external environment. As the core insulation layer within the cable, it directly determines the cable's electrical performance and safety rating. The sheath and other protective layers on the outside of the cable are designed to increase the cable's operating strength and environmental adaptability. The performance of the primary insulation is particularly important in high-voltage cables, as it must maintain good insulation 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 assess the insulation condition of their main insulation. How to efficiently and easily measure the insulation condition of the main insulation to ensure the safe operation of high-voltage cables is an important issue in the field of power safety.

[0046] A high-voltage cable segment refers to a technique in which the shielding layer of a high-voltage single-core cable is grounded. In order to reduce the induced current of the cable core current on the shielding layer, the entire 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 portion 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 segments 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 application calculates the dielectric loss of the high-voltage cable section by collecting the current data of each high-voltage cable section and the voltage data of the transformer substation, and determines the insulation state of the main insulation of the high-voltage cable section through the dielectric loss. Before measuring and evaluating the insulation state of the main insulation of the high-voltage cable section, the present application configures an insulation state online monitoring device for the high-voltage cable, the insulation state online monitoring device includes a voltage monitoring module deployed in the transformer substation and a current collection module deployed on both sides of each high-voltage cable section, and an optical fiber communication network connecting the voltage monitoring module and each current collection module. The optical fiber communication network can solve the problem of data synchronization and transmission caused by the absence of GPS and Beidou signals in the cable trench in the traditional method, improve the data synchronization accuracy, ensure that data synchronization can be quickly realized in harsh environments, thereby realizing online monitoring of the insulation state of the main insulation 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 section, the voltage data of the transformer substation is collected by the voltage monitoring module, the voltage data includes the three-phase voltage value of the transformer substation, and the current data of the high-voltage cable section is collected by the current collection module, 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 transformer substation to the metal sheath of the high-voltage cable section, and the output current represents 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 transformer substation.

[0051] Figure 3 is a kind of optional dielectric loss measurement schematic diagram of high-voltage cable interconnection part according to the embodiment of the present application, as Figure 3 The voltage monitoring unit (corresponding to the voltage detection module described above) is deployed at one end of the transformer substation, responsible for collecting the ABC three-phase voltage of the transformer substation, and each cross-interconnected high-voltage cable section is deployed with a current collection unit, Figure 3The current acquisition unit (corresponding to the current acquisition module) 1 is arranged between the substation and the three high-voltage cable sections A1, B1 and C1, and is used to acquire the input current of the three high-voltage cable sections A1, B1 and C1; the current acquisition unit (corresponding to the current acquisition module) 2 is arranged between the three high-voltage cable sections A1, B1 and C1 and the three high-voltage cable sections A2, B2 and C2, and is used to acquire the output current of the three high-voltage cable sections A1, B1 and C1 and the input current of the three high-voltage cable sections A2, B2 and C2; the current acquisition unit (corresponding to the current acquisition module) 3 is arranged between the three high-voltage cable sections A2, B2 and C2 and the three high-voltage cable sections A3, B3 and C3, and is used to acquire the output current of the three high-voltage cable sections A2, B2 and C2 and the input current of the three high-voltage cable sections A3, B3 and C3; and the current acquisition unit (corresponding to the current acquisition module) 4 is arranged between the three high-voltage cable sections A3, B3 and C3 and the three high-voltage cable sections A4, B4 and C4, and is used to acquire the output current of the three high-voltage cable sections A3, B3 and C3.

[0052] Figure 4 is a schematic diagram of an optional high-voltage cable section measurement device according to an embodiment of the present application, as shown in Figure 4 The high-voltage cable section measurement device spans the station end (corresponding to the substation) and the high-voltage cable, the station end is provided with a voltage monitoring unit (corresponding to the voltage monitoring module), and each high-voltage cable section in the underground cable corridor is provided with a current acquisition unit (corresponding to the current acquisition module) at both ends. Figure 4 In the embodiment, the current acquisition unit 1#, the current acquisition unit 2#, the current acquisition unit 3# and the current acquisition unit 4# are used for schematic illustration, and the current acquisition units correspond to the current acquisition modules), the voltage monitoring unit and the current acquisition units perform data synchronization through an optical fiber communication network (communication can be performed through the IEC61850 protocol), and are used for online monitoring of power data of the power system.

[0053] In step S102, a 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 a phase correction model to obtain a first type of phase value corresponding to the voltage of the high-voltage cable section.

[0054] It should be noted that after the voltage data of the substation is acquired, an initial phase value corresponding to the voltage of the substation needs to be calculated based on the voltage data of the substation to obtain a first type of initial phase value. In order to obtain a phase value corresponding to the voltage of each high-voltage cable section based on the phase value corresponding to the voltage of the substation, the first type of initial phase value needs to be corrected through a pre-constructed phase correction model, so as to obtain a first type of phase value corresponding to the voltage of each high-voltage cable section.

[0055] It should be noted that the phase correction model of the embodiment of the present application is a model for correcting the phase value of the voltage of the high-voltage cable section, which is constructed in advance based on a back propagation neural network.

[0056] Optionally, 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 transformer substation comprises: obtaining the power grid frequency and the data sampling frequency, and correcting the power grid frequency based on the voltage data of the transformer substation to obtain a corrected power grid frequency, wherein the power 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 the current data of the high-voltage cable section and the voltage data of the transformer substation corresponding to the high-voltage cable section; calculating the number of sampling points in one sampling period based on the data sampling frequency and the corrected power grid frequency; and calculating the phase value corresponding to the voltage of the transformer substation based on the three-phase voltage values of each sampling point in one sampling period and the number of sampling points, and taking the phase value corresponding to the voltage of the transformer substation as the first type of phase initial value corresponding to the voltage of the high-voltage cable section.

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

[0058] When calculating the phase value of the voltage, first, the number of sampling points in one sampling period after correction is calculated, that is, f S The data sampling frequency is represented by f, the corrected power grid frequency is represented by f, and the voltage value x(n) of each sampling point is determined, wherein n=1, 2, …, N-1, and the voltage value can be the A-phase voltage value, and then frequency domain transformation is performed to obtain the frequency domain representation of the voltage: Wherein, k is the frequency index, which represents different harmonic components, and j is the imaginary unit.

[0059] Optionally, the step of correcting the power grid frequency based on the voltage data of the transformer substation to obtain the corrected power grid frequency comprises: calculating the number of initial sampling points in 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; calculating the phase value corresponding to the voltage of the transformer substation in the first sampling period based on the three-phase voltage values of each sampling point in the first sampling period and the number of initial sampling points; calculating the phase value corresponding to the voltage of the transformer 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 initial sampling points; correcting the power grid frequency based on the phase value corresponding to the voltage of the transformer substation in the first sampling period and the phase value corresponding to the voltage of the transformer substation in the second sampling period to obtain the corrected power grid frequency.

[0060] It should be noted that the correction of the power grid frequency can guarantee the accuracy of the power grid frequency, thereby improving the accuracy of the subsequent calculation results. Specifically, the number of initial sampling points in a sampling period is calculated based on the power grid frequency and the data sampling frequency, and the number of sampling points in the whole period before correction is N0=(int)(f S ×0.02), where int is the integer of the calculation result, representing the data sampling frequency, and then two adjacent sampling periods, i.e. the first sampling period and the second sampling period, are selected, the phase angle φ1 of the first sampling period (the first N0 points) is calculated, the phase angle φ2 of the first sampling period (the last N0 points) is calculated, and the corrected power grid frequency is represented as: where f0 is the power grid frequency before correction.

[0061] 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 section comprises: obtaining the three-phase current and the three-phase power factor of the cable main core to obtain the three-phase current and the three-phase power factor of the high-voltage cable section; obtaining the length of the high-voltage cable section to be monitored to obtain the cable length value; obtaining the distance value between the first high-voltage cable section and the transformer substation, wherein the first high-voltage cable section represents the high-voltage cable section closest to the transformer 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 section and the transformer substation into the phase correction model to output the phase correction value corresponding to the voltage of the high-voltage cable section; 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 section.

[0062] It should be noted that the phase correction model can calculate the phase correction value of the high-voltage cable segment relative to the voltage of the transformer substation according to the main core current of the high-voltage cable segment, the phase value corresponding to the main core current, the distance between the high-voltage cable segment and the transformer substation, and the length of the high-voltage cable segment, thereby correcting the first type of phase initial value of each high-voltage cable segment to obtain the first type of phase value of each high-voltage cable segment, thereby improving the accuracy of the insulation state evaluation result, while ensuring the accuracy of the monitoring result and realizing automatic online monitoring. Specifically, when correcting the phase, first, the three-phase current and the three-phase power factor of the cable main core are obtained. The cable main core is the main component responsible for conducting current inside the cable and is located at the center of the cable and is wrapped by multiple layers of insulation material and protective layer. The insulation state of the cable directly affects the size and characteristics of the main core current. For example, aging or damage of the cable insulation material will increase the 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 voltage of the transformer substation can be corrected by measuring the main core current. At the same time, the cable length value of the high-voltage cable segment to be monitored and the distance between the high-voltage cable segment and the transformer substation are also obtained. The above data is input into the phase correction model to obtain the mapping relationship between the input data and the phase through the phase correction model, and the phase correction value of the voltage is output, thereby adding the first type of phase initial value of the high-voltage cable segment to the phase correction value to obtain the first type of 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: three-phase current and three-phase power factor of the cable main core on the high-voltage cable line, distance value between the transformer substation and the first high-voltage cable segment, length value of each high-voltage cable segment on the high-voltage cable line, and 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 obtaining the trained cable correction model in the case that the test result indicates that the cable correction model passes the test.

[0064] It should be noted that the phase correction model of the embodiment of the present application adopts a back propagation neural network and uses a back propagation algorithm for training. The phase correction network comprises an input layer, one or more hidden layers and an output layer. The neurons of each layer are connected to all the neurons of the next layer through weights and are used to correct the voltage phase angle of the high-voltage cable section to more accurately evaluate the dielectric loss of the high-voltage cable section. Specifically, when the phase correction model is iteratively trained, first, sample data for training is prepared. The sample data is obtained by simulating a simulation model of the high-voltage cable. Specifically, it 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 transformer substation and the first high-voltage cable section, the length value of each high-voltage cable section on the high-voltage cable line, and the phase correction value corresponding to the voltage of each high-voltage cable section on the high-voltage cable line. Then, the sample data set is divided into two parts, one for iterative training of the model and the other for performance testing of the model. The iterative training of the model specifically includes the following steps:

[0065] Forward propagation, the input signal is transmitted from the input layer to the hidden layer, and then to the output layer, and the output value is calculated. In this process, the signal is weighted and summed through the weights of the network, and then processed by the activation function to produce a new signal that is transmitted to the next layer.

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

[0067] Back propagation, the error is propagated from the output layer to the input layer, and the gradient is calculated to adjust the weights between the layers. 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, according to the gradient calculated by back propagation, the weights in the neural network are updated using an optimization algorithm.

[0069] Iterative training, repeat the above processes of forward propagation, error calculation, back propagation and weight update until the error between the predicted output of the network and the actual target value reaches a predetermined threshold, or the predetermined number of training times is reached.

[0070] Finally, the phase correction model obtained by iterative training is tested by a test set, the accuracy of the phase correction model is calculated, and if the calculated accuracy is greater than the pre-set accuracy threshold, it is determined that the model training is completed.

[0071] Step S103, calculate the second type of phase value corresponding to the leakage current of the high-voltage cable section based on the current data of the high-voltage cable section.

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

[0073] It should be noted that after the first type of phase value corresponding to the voltage of the high-voltage cable section is calculated, the phase value corresponding to the current of the high-voltage cable section is calculated based on the current data of the high-voltage cable section. The first type of phase value corresponding to the voltage is calculated in the same way, first calculating the number of sampling points in a corrected sampling period, that is f S , where n = 1, 2, …, N-1, the leakage current value is calculated by the input current and the output current of the high-voltage cable section, and then frequency domain transformation is performed to obtain the frequency domain representation of the voltage: , where k is the frequency index, representing different harmonic components, and j is the imaginary unit.

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

[0075] It should be noted that the dielectric loss of the high-voltage cable section can be calculated according to the corrected first type of phase value and the calculated second type of phase value. The dielectric loss can directly reflect the insulation state of the main insulation of the high-voltage cable section, because the dielectric loss is directly related to the properties of the insulation material. In particular, when the insulation material is aged, damp, contaminated or has defects, its dielectric loss characteristics will change significantly. Therefore, the insulation state of the main insulation of the high-voltage cable section can be evaluated by the dielectric loss of each high-voltage cable section, and subsequent improvement measures can be taken for the main insulation of the high-voltage cable section according to the specific insulation defect type.

[0076] Specifically, taking A1 section as an example, the dielectric loss angle of A1 section is calculated: , and the dielectric loss tan(δ A1 ) of A1 cable section is calculated based on the dielectric loss angle. The smaller the value of tan(δ A1 ), the lower the dielectric loss of A1 section, and the better the insulation performance of the main insulation of A1 section. Conversely,A1 The greater the value, the more energy is converted into heat in the dielectric, and the worse the insulation performance of the main insulation of the A1 section.

[0077] Through the above steps, the high-voltage cable section to be monitored is determined, 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, 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, and the output current represents the current output from the metal sheath of the high-voltage cable section, 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 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 for correcting the phase value of the voltage of the high-voltage cable section, which is constructed in advance based on a back propagation neural network, 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 the embodiment, when evaluating the insulation state of the main insulation of the high-voltage cable section, the current data of the high-voltage cable section and the voltage data of the substation connected to the high-voltage cable section are collected, the initial phase value of the voltage is calculated based on the voltage data, the initial phase value is corrected through the pre-constructed phase correction model to obtain the phase value corresponding to the voltage of the high-voltage cable section, and the phase value of the leakage current is calculated through the current data, so as to calculate the dielectric loss of the high-voltage cable section according to the phase value of the voltage and the phase value of the current, determine the insulation state of the main insulation part of the high-voltage cable section through the dielectric loss, the measurement method is simple, suitable for any measurement scene, and the purpose of accurate measurement is achieved, the effect of improving the accuracy of the insulation state measurement result is achieved, and the technical problem of low measurement result accuracy in measuring the insulation state of the main insulation of the high-voltage cable in the related art is solved.

[0079] The following will be described in detail in combination with another embodiment.

[0080] Embodiment two

[0081] The state determination device for the main insulation of the high-voltage cable provided in the embodiment includes a plurality of implementation units, each implementation unit corresponds to each implementation step in the aforementioned embodiment one, and the specific implementation manner and beneficial effects can be referred to the aforementioned method embodiment, which will not be described herein again.

[0082] Figure 5is a schematic diagram of an optional high-voltage cable main insulation state determination device according to an embodiment of the present application, as shown in the figure, the high-voltage cable main insulation state determination device can include: an acquisition unit 51, a correction unit 52, a calculation unit 53, a determination unit 54, wherein, Figure 5

[0083] The acquisition unit 51 is configured to determine a high-voltage cable segment to be monitored, acquire current data of the high-voltage cable segment and voltage data of a corresponding substation of 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 current input from the substation to the metal sheath of the high-voltage cable segment, the output current refers to current output from the metal sheath of the high-voltage cable segment, and the voltage data represents three-phase voltage values of the substation.

[0084] The correction unit 52 is configured to calculate first-type phase initial values corresponding to the voltage of the high-voltage cable segment based on the voltage data of the substation, and correct the first-type phase initial values based on a phase correction model to obtain first-type phase values corresponding to the voltage of the high-voltage cable segment, wherein the phase correction model is a model for correcting phase values of the voltage of the high-voltage cable segment, which is constructed in advance based on a back propagation neural network.

[0085] The calculation unit 53 is configured to calculate second-type phase values corresponding to leakage current of the high-voltage cable segment based on the current data of the high-voltage cable segment.

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

[0087] ​The state determination device of the high-voltage cable main insulation determines the high-voltage cable section to be monitored through the acquisition unit 51, acquires the current data of the high-voltage cable section and the voltage data of the corresponding transformer substation of the high-voltage cable section, 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 transformer substation to the metal sheath of the high-voltage cable section, and 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 transformer substation; the correction unit 52 calculates the first type of phase initial value corresponding to the voltage of the high-voltage cable section based on the voltage data of the transformer substation, and corrects 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 section, wherein the phase correction model is a model for correcting the phase value of the voltage of the high-voltage cable section, which is constructed in advance based on a back propagation neural network; the calculation unit 53 calculates the second type of phase value corresponding to the leakage current of the high-voltage cable section based on the current data of the high-voltage cable section; the determination unit 54 calculates the dielectric loss of the high-voltage cable section based on the first type of phase value and the second type of phase value, and determines the insulation state of the main insulation part of the high-voltage cable section based on the dielectric loss, and generates the state monitoring result of the high-voltage cable main insulation based on the insulation state of the main insulation part of the high-voltage cable section.

[0088] In the embodiment, when evaluating the insulation state of the main insulation of the high-voltage cable section, the current data of the high-voltage cable section and the voltage data of the transformer substation connected to the high-voltage cable section are acquired, the initial phase value of the voltage is calculated based on the voltage data, the initial phase value is corrected through the pre-constructed phase correction model to obtain the phase value corresponding to the voltage of the high-voltage cable section, and the phase value of the leakage current is calculated through the current data, so as to calculate the dielectric loss of the high-voltage cable section according to the phase value of the voltage and the phase value of the current, determine the insulation state of the main insulation part of the high-voltage cable section through the dielectric loss, and achieve the purpose of accurate measurement. The measurement method is simple and suitable for any measurement scene, and the purpose of accurate measurement is achieved, and the effect of improving the accuracy of the insulation state measurement result is achieved, thereby solving the technical problem of low measurement result accuracy in measuring the insulation state of the high-voltage cable main insulation in the related art.

[0089] Optionally, the correction unit comprises: a first correction module, configured to acquire the power grid frequency and the data sampling frequency, and correct the power grid frequency based on the voltage data of the transformer substation to obtain the corrected power grid frequency, wherein the power 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 the current data of the high-voltage cable section and the voltage data of the transformer substation corresponding to the high-voltage cable section; a first calculation module, configured to calculate the number of sampling points in one sampling period based on the data sampling frequency and the corrected power grid frequency; and a second calculation module, configured to calculate the phase value corresponding to the voltage of the transformer substation based on the three-phase voltage values of each sampling point in one sampling period and the number of sampling points, and take the phase value corresponding to the voltage of the transformer substation as the first type phase initial value corresponding to the voltage of the high-voltage cable section.

[0090] Optionally, the first correction module comprises: a first calculation submodule, configured to calculate the initial number of sampling points in one sampling period based on the power grid frequency and the data sampling frequency; a first selection submodule, configured to select two adjacent sampling periods to obtain a first sampling period and a second sampling period; a second calculation submodule, configured to calculate the phase value corresponding to the voltage of the transformer 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; a third calculation submodule, configured to calculate the phase value corresponding to the voltage of the transformer 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; and a first correction submodule, configured to correct the power grid frequency based on the phase value corresponding to the voltage of the transformer substation in the first sampling period and the phase value corresponding to the voltage of the transformer substation in the second sampling period to obtain the corrected power grid frequency.

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

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

[0093] Optionally, the high-voltage cable main insulation state determination apparatus further comprises: a first construction module configured 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 comprises: three-phase currents and three-phase power factors of the cable main core on the high-voltage cable line, distance values of the transformer substation and the first high-voltage cable section, length values of each high-voltage cable section on the high-voltage cable line, and phase correction values corresponding to voltages of each high-voltage cable section on the high-voltage cable line; a second construction module configured to construct an initial cable correction model based on a back propagation neural network; a first division module configured 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 configured to iteratively train the initial cable correction model through the training set to obtain a trained cable correction model; and a first test module configured to test the trained cable correction model based on the test set to obtain a test result, and obtain the trained cable correction model in a case where the test result indicates that the cable correction model passes the test.

[0094] Optionally, the high-voltage cable main insulation state determination apparatus further comprises: a first configuration module configured to configure a voltage monitoring module for the transformer substation; a second configuration module configured to configure a current acquisition module for the high-voltage cable section; and a first connection module configured to construct an optical fiber communication network and connect the voltage monitoring module and the current acquisition module based on the optical fiber communication network.

[0095] The high-voltage cable main insulation state determination apparatus can further comprise a processor and a memory, and the above-mentioned acquisition unit 51, correction unit 52, calculation unit 53, determination unit 54, etc. are stored in the memory as program units, and the corresponding functions are realized by the processor executing the above-mentioned program units stored in the memory.

[0096] The above-mentioned processor comprises a core, and the core retrieves the corresponding program unit from the memory. The core can be set to one or more, and the working state of the high-voltage cable main insulation is obtained by adjusting the core parameters.

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

[0098] According to another aspect of the embodiments of the present application, a computer readable storage medium is also provided, which includes a stored computer program, wherein the computer readable storage medium controls the device where the computer readable storage medium is located to perform any of the above-mentioned methods for determining the state of the main insulation of the high-voltage cable when the computer program is running.

[0099] According to another aspect of the embodiments of the present application, an electronic device is also provided, which includes one or more processors and a memory, and the memory is configured to store one or more programs, wherein the one or more programs, when executed by the one or more processors, cause the one or more processors to implement any of the above-mentioned methods for determining the state of the main insulation of the high-voltage cable.

[0100] According to another aspect of the embodiments of the present application, a computer program product is also provided, which includes a computer program, wherein the computer program, when executed by a processor, implements any of the above-mentioned methods for determining the state of the main insulation of the high-voltage cable.

[0101] The present application also provides a computer program product, which, when executed on a data processing device, is adapted to execute a program that is initialized with 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 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, and the voltage data represents three-phase voltage values 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 for correcting the phase value of the voltage of the high-voltage cable segment, which is constructed in advance based on a back propagation neural network; 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; calculating 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 determining the insulation state of the main insulation part of the high-voltage cable segment based on the dielectric loss, and generating a state 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.

[0102] The application further provides a computer program product, which is also suitable for executing the program of the following method steps when executed on a data processing device: 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 transformer substation comprises the steps of: obtaining the power grid frequency and the data sampling frequency, and correcting the power grid frequency based on the voltage data of the transformer substation to obtain the corrected power grid frequency, wherein the power 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 the current data of the high-voltage cable section and the voltage data of the transformer substation corresponding to the high-voltage cable section; calculating the number of sampling points in one sampling period based on the data sampling frequency and the corrected power grid frequency; calculating the phase value corresponding to the voltage of the transformer substation based on the three-phase voltage values of each sampling point in one sampling period and the number of sampling points, and taking the phase value corresponding to the voltage of the transformer substation as the first type of phase initial value corresponding to the voltage of the high-voltage cable section.

[0103] The application further provides a computer program product, which is also suitable for executing the program of the following method steps when executed on a data processing device: the step of correcting the power grid frequency based on the voltage data of the transformer substation to obtain the corrected power grid frequency comprises the steps of: calculating the initial number of sampling points in one 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; calculating the phase value corresponding to the voltage of the transformer 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 transformer 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 power grid frequency based on the phase value corresponding to the voltage of the transformer substation in the first sampling period and the phase value corresponding to the voltage of the transformer substation in the second sampling period to obtain the corrected power grid frequency.

[0104] The application further provides a computer program product, which is also suitable for executing the program of the following method steps when executed on a data processing device: 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 section comprises the steps of: obtaining the three-phase current and the three-phase power factor of the cable main core to obtain the three-phase current and the three-phase power factor of the high-voltage cable section; obtaining the length of the high-voltage cable section to be monitored to obtain the cable length value; obtaining the distance value between the first high-voltage cable section and the transformer substation, wherein the first high-voltage cable section represents the high-voltage cable section closest to the transformer 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 section and the transformer substation into the phase correction model to output the phase correction value corresponding to the voltage of the high-voltage cable section; 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 section.

[0105] The application further provides a computer program product, which, when executed on a data processing device, is further adapted to execute a program for initializing the following method steps: the step of calculating the second-type phase value corresponding to the leakage current of the high-voltage cable section based on the current data of the high-voltage cable section comprises the following steps: calculating the number of sampling points in a sampling period based on the data sampling frequency and the corrected power grid frequency; calculating the leakage current of the high-voltage cable section at each sampling point in a sampling period based on the input current and the output current of each sampling point in a sampling period in the current data of the high-voltage cable section; and calculating the second-type phase value corresponding to the leakage current of the high-voltage cable section based on the leakage current of the high-voltage cable section at each sampling point in a sampling period and the number of sampling points.

[0106] The application further provides a computer program product, which, when executed on a data processing device, is further adapted to execute a program for initializing the following method steps: the phase correction model is pre-constructed, and the step of constructing the phase correction model comprises the following steps: 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 comprises: three-phase currents and three-phase power factors of a cable main core on the high-voltage cable line, distance values of the transformer substation and the first high-voltage cable section, length values of each high-voltage cable section on the high-voltage cable line, and phase correction values corresponding to voltages of each high-voltage cable section 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 obtaining the trained cable correction model in the case that the test result indicates that the cable correction model passes the test.

[0107] The application further provides a computer program product, which, when executed on a data processing device, is further adapted to execute a program for initializing the following method steps: before determining the high-voltage cable section to be monitored, the method further comprises the following steps: configuring a voltage monitoring module for the transformer substation; configuring a current collection module for the high-voltage cable section; constructing an optical fiber communication network, and connecting the voltage monitoring module and the current collection module based on the optical fiber communication network.

[0108] Figure 6 is a hardware structure block diagram of an electronic device (or a mobile device) for a method for determining the state of a high-voltage cable main insulation according to an embodiment of the application. As shown in Figure 6 , the electronic device can include one or more processors ( Figure 6The electronic device can further include a display, an input / output interface (I / O interface), a universal serial bus (USB) port (which can be included as one of the ports of the I / O interface), a network interface, a keyboard, a power supply, and / or a camera. Figure 6 The structure shown is merely schematic, and does not limit the structure of the electronic device described above. For example, the electronic device can further include more or fewer components than those shown in the figure, or have a different configuration from that shown in the figure. Figure 6 The structure shown is merely schematic, and does not limit the structure of the electronic device described above. For example, the electronic device can further include more or fewer components than those shown in the figure, or have a different configuration from that shown in the figure. Figure 6 The structure shown is merely schematic, and does not limit the structure of the electronic device described above. For example, the electronic device can further include more or fewer components than those shown in the figure, or have a different configuration from that shown in the figure.

[0109] The above-mentioned embodiment numbers of the present application are merely for description, and do not represent the advantages or disadvantages of the embodiments.

[0110] In the above-described embodiments of the present application, the description of each embodiment has its own focus, and the parts not described in detail in a certain embodiment can be referred to the relevant description of other embodiments.

[0111] In several embodiments provided in the present application, it should be understood that the disclosed technical contents can be implemented by other ways. Among them, the above-described device embodiments are only schematic, for example, the division of units can be a logical function division, and actual implementation can have another division way, for example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the units or modules shown or discussed can be indirect coupling or communication connection through some interfaces, units or modules, which can be electrical or other forms.

[0112] The units described as separate components can or can not be physically separated, and the components shown as units can or can not be physical units, i.e. they can be located in one place or distributed on multiple units. Part or all of the units can 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 application can be integrated in one processing unit, or each unit can exist physically, or two or more units can be integrated in one unit. The above integrated unit can be realized in the form of hardware or in the form of software functional unit.

[0114] The integrated unit, if implemented in the form of a software function unit and sold or used as an independent product, can be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the present application, essentially or in other words, the part that contributes to the prior art or the whole or part of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium, including a number of instructions to make a computer device (which can be a personal computer, a server or a network device, etc.) execute all or part of the steps of the methods described in various embodiments of the present application. The aforementioned storage medium includes: a U disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a mobile hard disk, a magnetic disk or an optical disk, and various media that can store program codes.

[0115] The above is only the preferred embodiment of the present application, and it should be pointed out that for those skilled in the art, without departing from the principles of the present application, a number of improvements and refinements can be made, and these improvements and refinements should be considered as the protection scope of the present application.

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, and collect 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 represents the current output from the high-voltage cable segment to the metal sheath, and the voltage data represents the three-phase voltage values ​​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 correcting the first-type phase initial value based on a phase correction model to obtain a first-type phase value corresponding to the voltage of the high-voltage cable segment, including: 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 a cable length value; obtaining a distance value between a 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 a 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, 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 phase value and the second-type 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.

2. The determination method according to claim 1, characterized in that The step of calculating the first type phase initial value corresponding to the voltage of the high-voltage cable section 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 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; Calculating the number of sampling points in a sampling period based on the data sampling frequency and the corrected 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 within 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: Calculating the number of initial sampling points within 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 a 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 a 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 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 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 includes: Calculating the number of sampling points in 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; 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.

5. 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 a main cable core on the high-voltage cable line, a distance between the substation and the first high-voltage cable segment, a length 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 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. If the test result indicates that the cable correction model passes the test, the trained cable correction model is obtained.

6. 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.

7. A device for determining the state of the main insulation of a high-voltage cable, characterized in that: include: a collection unit, configured to determine a high-voltage cable segment to be monitored, and 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 representing current input from the substation to the metal sheath of the high-voltage cable segment, the output current representing current output from the high-voltage cable segment to the metal sheath, and the voltage data representing three-phase voltage values ​​of the substation; a correction unit, configured to calculate 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 correct the first-type phase initial value based on a phase correction model to obtain a first-type 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; 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 of the high-voltage cable segment into the phase correction model, and output a phase correction value corresponding to the voltage of the high-voltage cable segment; a second correction module, used to correct the first-type phase initial value based on the phase correction value, and obtain the first-type phase value corresponding to 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-type phase value and the second-type phase value, 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.

8. 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 status of the main insulation of a high-voltage cable according to any one of claims 1 to 6.

9. An electronic device, characterized in that: The method 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 status of the main insulation of a high-voltage cable as described in any one of claims 1 to 6.

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