Method and system for monitoring thermal-mechanical stress of high-voltage cable terminals in extremely cold environments

Abstract

The present invention provides a method and system for monitoring thermal-mechanical stress of high-voltage cable terminals in an extremely cold environment, which can be applied to the field of high voltage technology. The method includes: according to the relationship between time and electric load, a predetermined current is passed into the circuit where the cable terminal to be tested is located in a predetermined period of time, wherein the relationship between time and electric load is obtained by processing the real electric load current carrying capacity data of the predetermined geographical location; according to the relationship between time and air temperature, the external environment where the cable terminal to be tested is located is adjusted to a predetermined external temperature in a predetermined period of time, wherein the relationship between time and air temperature is obtained by processing the real environment data of the predetermined geographical location; under the conditions of a predetermined current and a predetermined external temperature, the test data between two adjacent structural layers of the cable terminal to be tested is obtained; based on multiple different test data, the thermal and stress test results of the cable terminal to be tested are obtained.

Description

Technical Field

[0001] The present invention relates to the field of high voltage technology, and in particular to a method and system for monitoring thermal-mechanical stress of a high voltage cable terminal in an extremely cold environment. Background Art

[0002] As the core component of the power system, cables are responsible for the transmission of electricity. However, cable terminals are the weakest link in the cable system due to their complex structure and multiple insulation types. For example, in extremely cold weather, the large temperature difference between the ambient temperature and the temperature inside the cable may cause the cable terminal to explode, thus affecting the safe and stable operation of the power grid.

[0003] The insulation design of the cable terminal is composed of at least two insulating materials. In order to reduce the contact air gap between the two and improve the insulation performance, a certain pressure is often applied to the interface during installation. However, the pressure is greatly affected by heat, and the interface pressure inside the cable terminal changes all the time. During normal operation, the current flowing through the conductor will cause it to heat up. At this time, if the ambient temperature drops sharply, a huge temperature gradient will be generated inside and outside, resulting in mechanical stress caused by heat, affecting the interface pressure. Therefore, it is urgent to simulate the operation of cable terminals in extremely cold environments and study the thermal-mechanical stress distribution of each internal structural layer.

[0004] In the process of implementing the present invention, it is found that the prior art has at least the following problems: in the process of simulation to study thermal and mechanical stress, usually only simulation under room temperature conditions is achieved, and it is impossible to study the correlation between internal heat and mechanical stress under extreme cold or different temperature conditions. Summary of the invention

[0005] In view of the above problems, the present invention provides a method and system for monitoring thermal-mechanical stress of high-voltage cable terminals in an extremely cold environment.

[0006] According to a first aspect of the present invention, a method for monitoring thermal-mechanical stress of a high-voltage cable terminal in an extremely cold environment is provided, comprising: according to the relationship between time and electric load, a predetermined current is passed through the circuit where the cable terminal to be tested is located during a predetermined period of time, wherein the relationship between time and electric load is obtained by processing the actual electric load current carrying capacity data at a predetermined geographical location; according to the relationship between time and air temperature, the external environment where the cable terminal to be tested is located is adjusted to a predetermined external temperature during a predetermined period of time, wherein the relationship between time and air temperature is obtained by processing the actual environment data at a predetermined geographical location; under the conditions of a predetermined current and a predetermined external temperature, test data between two adjacent structural layers of the cable terminal to be tested is obtained, wherein the test data includes a plurality of test sub-data located at different length positions of the cable terminal to be tested, each test sub-data including temperature data and pressure data; and based on the different plurality of test data, a thermal and stress test result of the cable terminal to be tested is obtained.

[0007] According to an embodiment of the present invention, test data between two adjacent structural layers of a cable terminal to be tested is obtained, including: determining the terminal type of the cable terminal to be tested; and obtaining multiple test sub-data using a pressure sensor and a temperature sensor arranged at multiple different terminal test positions to obtain test data, wherein the terminal test position includes a position between two adjacent structural layers that matches the terminal type, and the two adjacent structural layers include a cable insulation layer and a stress cone and / or a stress cone and an epoxy interface layer.

[0008] According to an embodiment of the present invention, a method for monitoring thermal-mechanical stress of a high-voltage cable terminal in an extremely cold environment further includes: determining a plurality of different terminal test positions of the cable terminal to be tested based on the terminal type of the cable terminal to be tested, wherein the terminal test position includes a terminal pressure test position and a terminal temperature test position, and the terminal pressure test positions and terminal temperature test positions of the same group are on the same circumference of the cable terminal to be tested and are 180° apart; and respectively setting pressure sensors and temperature sensors at the plurality of terminal test positions.

[0009] According to an embodiment of the present invention, a plurality of test sub-data are acquired by using a pressure sensor and a temperature sensor disposed at a plurality of different terminal test positions, including: acquiring a plurality of initial test sub-data by using a pressure sensor and a temperature sensor disposed at a plurality of different terminal test positions; and obtaining test sub-data based on the initial test sub-data when a pressure change value of the pressure data within a predetermined pressure change period is less than a predetermined pressure threshold, and when a temperature change value of the temperature data within a predetermined temperature change period is less than a predetermined temperature threshold.

[0010] According to an embodiment of the present invention, based on the relationship between time and electric load, a predetermined current is passed through the loop where the cable terminal to be tested is located during a predetermined period of time, including: determining the amount of change in electric load at a predetermined geographical location during the predetermined period of time based on the relationship between time and electric load; and based on the amount of change in electric load, using a voltage regulator to adjust the input power of a through-hole transformer configured in the loop until the predetermined current is passed through the loop within the predetermined period of time.

[0011] According to an embodiment of the present invention, based on the relationship between time and temperature, the external environment of the cable terminal to be tested is adjusted to a predetermined external temperature during a predetermined period of time, including: determining the temperature difference of a predetermined geographical location within the predetermined period of time based on the relationship between time and temperature; and based on the temperature difference, adjusting the cabin environment of the experimental cabin where the loop of the cable terminal to be tested is located to the predetermined external temperature.

[0012] According to an embodiment of the present invention, based on multiple different test data, thermal and stress test results of the cable terminal to be tested are obtained, including: based on the multiple test data, obtaining the temperature and pressure change curves over time of each of multiple adjacent structural layers of the cable terminal to be tested; and based on the temperature and pressure change curves over time, obtaining the thermal and stress test results of the cable terminal to be tested.

[0013] A second aspect of the present invention provides a high voltage cable terminal thermal-mechanical stress monitoring system in an extremely cold environment, comprising:

[0014] A loop, wherein the loop is used to connect a terminal of a cable to be tested;

[0015] A sensor, used for detecting test data between two adjacent structural layers of a cable terminal to be tested;

[0016] The controller is used to determine the predetermined current to be passed into the circuit where the cable terminal to be tested is located during the predetermined period of time according to the relationship between time and electric load, and input a current adjustment instruction to the current regulator based on the predetermined current; it is used to determine the predetermined external temperature of the cable terminal to be tested during the predetermined period of time according to the relationship between time and air temperature, and input a temperature adjustment instruction to the temperature regulator based on the predetermined external temperature; it is also used to receive test data sent by the sensor, and obtain heat and stress test results of the cable terminal to be tested based on multiple different test data;

[0017] A current regulator, for regulating a predetermined current to be passed into the circuit in response to a current regulation instruction;

[0018] The temperature regulator is used to adjust the terminal of the cable to be tested to a predetermined external temperature in response to a temperature adjustment instruction.

[0019] According to an embodiment of the present invention, the cable terminal to be tested includes multiple different types, and the high-voltage cable terminal thermal-mechanical stress monitoring system under extreme cold environment also includes: an experimental cabin, wherein at least one target temperature sensor matching the cable terminal to be tested is arranged in the experimental cabin; the distance between the cable terminal to be tested and the at least one target temperature sensor is less than a predetermined distance threshold.

[0020] According to an embodiment of the present invention, the regulating capacity of the temperature regulator is greater than the maximum temperature variation in the relationship between time and air temperature.

[0021] A third aspect of the present invention provides an electronic device, comprising: one or more processors; a memory for storing one or more computer programs, wherein the one or more processors execute the one or more computer programs to implement the steps of the above method.

[0022] The fourth aspect of the present invention further provides a computer-readable storage medium on which a computer program or instruction is stored, and the steps of the above method are implemented when the above computer program or instruction is executed by a processor.

[0023] The fifth aspect of the present invention also provides a computer program product, including a computer program or instructions, which implement the steps of the above method when executed by a processor.

[0024] According to an embodiment of the present invention, a predetermined current is passed into the circuit where the cable terminal to be tested is located according to the relationship between time and electric load, and the external environment where the cable terminal to be tested is located is adjusted to a predetermined external temperature according to the relationship between time and air temperature, and the pressure and temperature conditions in the cable terminal to be tested are collected to determine the heat and stress test results of the cable terminal to be tested. Since the relationship between time and electric load and the relationship between time and air temperature are determined based on actual data, the current and temperature conditions of the cable terminal to be tested are the same as the actual conditions, thereby improving the simulation effect. In addition, in the case where the relationship between time and electric load and the relationship between time and air temperature represent changes in current and temperature, the current and ambient temperature of the cable to be tested can be changed in time, thereby further improving the simulation effect, enriching the detection environment, and improving the accuracy of the heat and stress test results of the cable terminal to be tested. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The above contents and other objects, features and advantages of the present invention will become more apparent through the following description of the embodiments of the present invention with reference to the accompanying drawings, in which:

[0026] Figure 1 A flow chart of a method for monitoring thermal-mechanical stress of a high-voltage cable terminal in an extreme cold environment according to an embodiment of the present invention is shown.

[0027] Figure 2 A structural diagram of a thermal-mechanical stress monitoring system for high-voltage cable terminals in an extreme cold environment according to an embodiment of the present invention is shown.

[0028] Figure 3 A schematic diagram of sensor locations of a GIS cable terminal according to an embodiment of the present invention is shown.

[0029] Figure 4 A schematic diagram showing sensor locations of an outdoor cable terminal according to an embodiment of the present invention is shown.

[0030] Figure 5 A block diagram of an electronic device suitable for implementing a method for monitoring thermal-mechanical stress of a high-voltage cable terminal in an extreme cold environment according to an embodiment of the present invention is shown.

[0031] In the figure, loop 1, through-core transformer 2, experimental cabin 3, current controller 4, temperature controller 5, temperature regulator 6, target temperature sensor 7, cable terminal to be tested 8, cable terminal to be tested 9, cables at both ends 10, conductor connecting wire 11, cable bracket 12, voltage regulator 13, temperature sensor 14 and pressure sensor 15. DETAILED DESCRIPTION

[0032] Below, embodiments of the present invention will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the present invention. In the following detailed description, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of embodiments of the present invention. However, it is apparent that one or more embodiments may also be implemented without these specific details. In addition, in the following description, descriptions of known structures and technologies are omitted to avoid unnecessary confusion of concepts of the present invention.

[0033] The terms used herein are only for describing specific embodiments and are not intended to limit the present invention. The terms "comprise", "include", etc. used herein indicate the existence of the features, steps, operations and / or components, but do not exclude the existence or addition of one or more other features, steps, operations or components.

[0034] All terms (including technical and scientific terms) used herein have the meanings commonly understood by those skilled in the art unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification and should not be interpreted in an idealized or overly rigid manner.

[0035] An embodiment of the present invention provides a method for monitoring thermal-mechanical stress of a high-voltage cable terminal in an extremely cold environment, comprising: according to the relationship between time and electric load, a predetermined current is passed through the circuit where the cable terminal to be tested is located during a predetermined period of time, wherein the relationship between time and electric load is obtained by processing the actual electric load current carrying capacity data at a predetermined geographical location; according to the relationship between time and air temperature, the external environment where the cable terminal to be tested is located is adjusted to a predetermined external temperature during a predetermined period of time, wherein the relationship between time and air temperature is obtained by processing the actual environment data at a predetermined geographical location; under the conditions of a predetermined current and a predetermined external temperature, test data between two adjacent structural layers of the cable terminal to be tested is obtained, wherein the test data includes multiple test sub-data located at different length positions of the cable terminal to be tested, each test sub-data includes temperature data and pressure data; and based on the different multiple test data, a thermal and stress test result of the cable terminal to be tested is obtained.

[0036] Figure 1 A flow chart of a method for monitoring thermal-mechanical stress of a high-voltage cable terminal in an extreme cold environment according to an embodiment of the present invention is shown.

[0037] like Figure 1 As shown, the method for monitoring thermal-mechanical stress of a high-voltage cable terminal in an extreme cold environment of this embodiment includes operations S110 to S140.

[0038] In operation S110, according to the relationship between time and electric load, a predetermined current is passed into the loop where the cable terminal to be tested is located in a predetermined period of time.

[0039] According to an embodiment of the present invention, the relationship between time and electric load is obtained by processing the real electric load current carrying data at a predetermined geographical location. The predetermined geographical location is the real geographical location of the cable that needs to be simulated when performing thermal-mechanical stress monitoring of high-voltage cable terminals in an extremely cold environment, and the real electric load current carrying data is the historical electric load current carrying data of the cable at the predetermined geographical location, which can be determined by investigating the historical data. The predetermined period is the period during the process of performing thermal-mechanical stress monitoring of high-voltage cable terminals in an extremely cold environment.

[0040] According to an embodiment of the present invention, the actual electric load current carrying capacity data of the cable at the predicted geographical location is obtained, and then the relationship between time and electric load of the cable at the predicted geographical location is determined, and a predetermined current is passed through the loop where the terminal of the cable to be tested is located during a predetermined period of time to simulate the electric load condition of the cable at the predicted geographical location.

[0041] For example, the relationship between time and electric load may be determined through a daily load curve of a predetermined geographical location, wherein the daily load curve may include a trend of electric load variation over time within a day.

[0042] In operation S120, according to the relationship between time and air temperature, the external environment of the cable terminal to be tested is adjusted to a predetermined external temperature during a predetermined period of time.

[0043] According to an embodiment of the present invention, the relationship between time and temperature is obtained by processing real environmental data of a predetermined geographical location. The real environmental data is historical environmental data of a predetermined geographical location, and may include environmental data such as temperature.

[0044] According to an embodiment of the present invention, historical environmental data of the predicted geographic location is obtained to determine the relationship between the time and the temperature of the predicted geographic location, and the external environment of the cable terminal to be tested is adjusted to a predetermined external temperature during a predetermined period to simulate the environmental conditions of the predicted geographic location, wherein the predetermined external temperature can be determined based on the current time and the relationship between time and temperature.

[0045] For example, the relationship between time and temperature may be determined by a daily ambient temperature variation curve at a predetermined geographic location, wherein the daily ambient temperature variation curve may include a variation trend of the temperature over time within a day.

[0046] In operation S130, under the conditions of a predetermined current and a predetermined external temperature, test data between two adjacent structural layers of the cable terminal to be tested is obtained.

[0047] According to an embodiment of the present invention, the cable terminal to be tested may include two or more structural layers, each structural layer is wrapped by insulating material, the greater the pressure between two adjacent structural layers, the smaller the contact air gap, and the better the insulation performance.

[0048] According to an embodiment of the present invention, taking one end of the cable terminal to be tested as a reference point, a plurality of length positions are determined on the cable terminal to be tested, wherein different length positions have different distances from the reference point, and the test data includes a plurality of test sub-data located at different length positions of the cable terminal to be tested, each test sub-data including temperature data and pressure data, the temperature data including the temperature of the cable terminal to be tested at the length position at the time when the test data is acquired, and the pressure data including the pressure of the cable terminal to be tested at the length position at the time when the test data is acquired.

[0049] According to an embodiment of the present invention, test data between adjacent beam structure layers are determined based on temperature data and pressure data.

[0050] In operation S140, a heat and stress test result of the cable terminal to be tested is obtained based on a plurality of different test data.

[0051] According to an embodiment of the present invention, test data between two adjacent structural layers in multiple structural layers of a cable terminal to be tested are collected respectively to obtain multiple test data, and the temperature change and pressure change of the cable terminal to be tested are determined respectively according to the multiple temperature data and the multiple pressure data. Based on the temperature change and the pressure change, the thermal and stress test results of the cable terminal to be tested are determined, wherein the thermal and stress test results can be used to characterize the correspondence between the ambient temperature and pressure of the cable to be tested.

[0052] According to an embodiment of the present invention, a predetermined current is passed into the circuit where the cable terminal to be tested is located according to the relationship between time and electric load, and the external environment where the cable terminal to be tested is located is adjusted to a predetermined external temperature according to the relationship between time and air temperature, and the pressure and temperature conditions in the cable terminal to be tested are collected to determine the heat and stress test results of the cable terminal to be tested. Since the relationship between time and electric load and the relationship between time and air temperature are determined based on actual data, the current and temperature conditions of the cable terminal to be tested are the same as the actual conditions, thereby improving the simulation effect. In addition, in the case where the relationship between time and electric load and the relationship between time and air temperature represent changes in current and temperature, the current and ambient temperature of the cable to be tested can be changed in time, thereby further improving the simulation effect, enriching the detection environment, and improving the accuracy of the heat and stress test results of the cable terminal to be tested.

[0053] According to an embodiment of the present invention, test data between two adjacent structural layers of a cable terminal to be tested is obtained, including: determining the terminal type of the cable terminal to be tested; and obtaining multiple test sub-data using a pressure sensor and a temperature sensor arranged at multiple different terminal test positions to obtain test data, wherein the terminal test position includes a position between two adjacent structural layers that matches the terminal type, and the two adjacent structural layers include a cable insulation layer and a stress cone and / or a stress cone and an epoxy interface layer.

[0054] According to an embodiment of the present invention, the terminal types of the cable terminals to be tested may include GIS cable terminals for gas insulated switchgear (GIS), and may also include outdoor cable terminals for use in outdoor environments, wherein, due to differences in the structures of different terminal types, different terminal types may correspond to different terminal test positions.

[0055] According to an embodiment of the present invention, after determining the terminal type of the cable terminal to be tested, the terminal test position matching the terminal type is determined, and pressure sensors and temperature sensors arranged at multiple different terminal test positions are used to obtain multiple test sub-data between two adjacent structural layers.

[0056] According to an embodiment of the present invention, two adjacent structural layers include a cable insulation layer and a stress cone and / or a stress cone and an epoxy interface layer, and the stress cone includes a stress cone root, a stress cone middle and a stress cone head.

[0057] According to the embodiment of the present invention, since the test data is collected based on the pressure sensors and temperature sensors at multiple different terminal test positions, the comprehensiveness of the test data is improved, thereby improving the accuracy of the test.

[0058] According to an embodiment of the present invention, a method for monitoring thermal-mechanical stress of a high-voltage cable terminal in an extremely cold environment further includes: determining a plurality of different terminal test positions of the cable terminal to be tested based on the terminal type of the cable terminal to be tested, wherein the terminal test position includes a terminal pressure test position and a terminal temperature test position, and the terminal pressure test positions and terminal temperature test positions of the same group are on the same circumference of the cable terminal to be tested and are 180° apart; and respectively setting pressure sensors and temperature sensors at the plurality of terminal test positions.

[0059] According to an embodiment of the present invention, according to the terminal type of the cable terminal to be tested, a plurality of terminal test positions corresponding to the terminal type can be determined on the cable terminal to be tested. The terminal test positions include a plurality of groups of test positions, each group of test positions including a terminal pressure test position and a terminal temperature test position.

[0060] According to an embodiment of the present invention, in order to ensure that the pressure data and temperature data of the same group of tests are data at the same length position in the cable terminal to be tested, the terminal pressure test position and the terminal temperature test position of the same group can be placed on the same circumference of the cable terminal to be tested.

[0061] According to an embodiment of the present invention, in order to avoid mutual influence among different sensors in the process of obtaining pressure data and temperature data, the distance between the terminal pressure test position and the terminal temperature test position can be set as large as possible. Since the cable terminal to be tested is a cylinder, the line segment between the two ends of the diameter on the circumference of a cross section of the cylinder is the longest. Therefore, the terminal pressure test position and the terminal temperature test position can be respectively set at the two ends of the diameter of the same circle, that is, 180° apart.

[0062] According to an embodiment of the present invention, after a plurality of terminal test positions are determined, pressure sensors are respectively arranged at the plurality of terminal pressure test positions, and temperature sensors are respectively arranged at the plurality of terminal temperature test positions.

[0063] According to an embodiment of the present invention, by setting the terminal pressure test position and the terminal temperature test position of different terminal types, it is possible to ensure that the pressure data and the temperature data of the same group of tests are at the same length position in the cable terminal to be tested, thereby improving the accuracy of data collection. In addition, by setting the terminal pressure test position and the terminal temperature test position to be on the same circumference 180° apart, the mutual influence between the two test positions can be reduced by increasing the distance between the test positions, thereby further improving the accuracy of data collection.

[0064] According to an embodiment of the present invention, a plurality of test sub-data are acquired by using a pressure sensor and a temperature sensor disposed at a plurality of different terminal test positions, including: acquiring a plurality of initial test sub-data by using a pressure sensor and a temperature sensor disposed at a plurality of different terminal test positions; and obtaining test sub-data based on the initial test sub-data when a pressure change value of the pressure data within a predetermined pressure change period is less than a predetermined pressure threshold, and when a temperature change value of the temperature data within a predetermined temperature change period is less than a predetermined temperature threshold.

[0065] According to an embodiment of the present invention, pressure sensors and temperature sensors disposed at a plurality of different terminal test positions are used to collect pressure data and temperature data, respectively, to obtain a plurality of initial test sub-data.

[0066] According to an embodiment of the present invention, the pressure change value of the pressure data in each initial test sub-data within a predetermined pressure change period, and the temperature change value of the temperature data in each initial test sub-data within a predetermined temperature change period are determined, wherein the predetermined pressure change period and the predetermined temperature change period can be 30 minutes.

[0067] According to an embodiment of the present invention, the pressure change value of the pressure data within a predetermined pressure change period is compared with the predetermined pressure threshold, and the temperature change value of the temperature data within a predetermined temperature change period is compared with the predetermined temperature threshold. When the pressure change value is greater than the predetermined pressure threshold and / or the temperature change value is greater than the predetermined temperature threshold, it can be determined that the pressure and / or temperature changes of the current cable terminal to be tested are unstable. If the pressure change value is less than the predetermined pressure threshold and the temperature change value is less than the predetermined temperature threshold, it can be determined that the pressure and temperature changes of the current cable terminal to be tested are already in a stable state, and the initial test sub-data can be used as the test sub-data. The predetermined pressure threshold can be 0.003Mpa / 30min, and the predetermined temperature threshold can be 0.3℃ / 30min.

[0068] According to an embodiment of the present invention, respective pressure change values ​​and temperature change values ​​are determined according to a predetermined pressure change period and a predetermined temperature change period, and the pressure change values ​​and temperature change values ​​are compared with a predetermined pressure threshold and a predetermined temperature threshold, respectively. When it is determined that the pressure change value is less than the predetermined pressure threshold and the temperature change value is less than the temperature change threshold, the initial test sub-data is used as the test sub-data, which can ensure that the pressure and temperature changes in the environment are relatively stable. When a steady state is reached, the test sub-data is determined again, thereby avoiding data errors caused by rapid changes in the simulation environment and ensuring the stability and accuracy of the test.

[0069] According to an embodiment of the present invention, based on the relationship between time and electric load, a predetermined current is passed through the loop where the cable terminal to be tested is located during a predetermined period of time, including: determining the amount of change in electric load at a predetermined geographical location during the predetermined period of time based on the relationship between time and electric load; and based on the amount of change in electric load, using a voltage regulator to adjust the input power of a through-hole transformer configured in the loop until the predetermined current is passed through the loop within the predetermined period of time.

[0070] According to an embodiment of the present invention, based on a predetermined time period and the relationship between time and electric load, the change in electric load at a predetermined geographical location within the predetermined time period, that is, the change in electric load at a predetermined geographical location within the predetermined time period, is determined, and based on the change in electric load, a voltage regulator is used to adjust the input power of a through-hole transformer configured in the loop, thereby changing the current in the loop until the current in the loop is adjusted to be the same as the predetermined current.

[0071] According to an embodiment of the present invention, based on the relationship between time and electric load, the change in electric load at a predetermined geographical location within a predetermined time period can be accurately determined, so that the current in the loop can be adjusted in time so that the current in the loop is the same as the predetermined current, thereby improving the authenticity of the simulation and further improving the accuracy of the test.

[0072] According to an embodiment of the present invention, based on the relationship between time and temperature, the external environment of the cable terminal to be tested is adjusted to a predetermined external temperature during a predetermined period of time, including: determining the temperature difference of a predetermined geographical location within the predetermined period of time based on the relationship between time and temperature; and based on the temperature difference, adjusting the cabin environment of the experimental cabin where the loop of the cable terminal to be tested is located to the predetermined external temperature.

[0073] According to an embodiment of the present invention, the circuit of the cable terminal to be tested may be arranged in a test chamber, and the test chamber may further include a temperature control device for regulating the temperature in the chamber.

[0074] According to an embodiment of the present invention, based on a predetermined time period and the relationship between time and air temperature, the temperature difference of a predetermined geographical location within the predetermined time period is determined, and the cabin environment of the experimental cabin where the loop of the cable terminal to be tested is located is adjusted according to the temperature difference until it is adjusted to a predetermined external temperature.

[0075] According to an embodiment of the present invention, based on the relationship between time and air temperature, the temperature difference at a predetermined geographical location within a predetermined period of time can be accurately determined, so that the cabin environment where the loop of the cable terminal to be tested is located can be adjusted in time to make the cabin environment the same as the predetermined external temperature, thereby further improving the authenticity of the simulation and further improving the accuracy of the test.

[0076] According to an embodiment of the present invention, based on multiple different test data, thermal and stress test results of the cable terminal to be tested are obtained, including: based on the multiple test data, obtaining the temperature and pressure change curves over time of each of multiple adjacent structural layers of the cable terminal to be tested; and based on the temperature and pressure change curves over time, obtaining the thermal and stress test results of the cable terminal to be tested.

[0077] According to an embodiment of the present invention, each test data includes a corresponding set of temperature data and pressure data that change with time, and based on each test data, the temperature and pressure change curves of two adjacent structural layers of the cable terminal to be tested over time can be determined. Based on multiple test data, the temperature and pressure change curves of two different adjacent structural layers of the cable terminal to be tested over time can be determined.

[0078] According to an embodiment of the present invention, based on the temperature and pressure change curves over time, the temperature and pressure of the cable terminal to be tested can be analyzed to determine the influence of the temperature of the environment in which the cable terminal to be tested is located on the pressure between two adjacent structural layers of the cable terminal to be tested, thereby obtaining the thermal and stress test results of the cable terminal to be tested.

[0079] According to an embodiment of the present invention, by converting test data into a curve of temperature and pressure changing over time, the changing relationship between heat and stress of the cable terminal to be tested can be determined more intuitively, thereby improving test efficiency and test accuracy, reducing the difficulty of data analysis, and improving the ease of use of the test.

[0080] Based on the above-mentioned method for monitoring thermal-mechanical stress of high-voltage cable terminals in extremely cold environments, the present invention also provides a system for monitoring thermal-mechanical stress of high-voltage cable terminals in extremely cold environments. Figure 2 The system is described in detail.

[0081] Figure 2 A structural diagram of a thermal-mechanical stress monitoring system for high-voltage cable terminals in an extreme cold environment according to an embodiment of the present invention is shown.

[0082] like Figure 2 As shown, the thermal-mechanical stress monitoring system for high-voltage cable terminals in an extremely cold environment of this embodiment includes a loop 1, a through-core transformer 2, a test cabin 3, a current controller 4, a temperature controller 5, a temperature regulator 6, a target temperature sensor 7, a cable terminal to be tested 8, a cable terminal to be tested 9, cables at both ends 10, a conductor connecting line 11, a cable bracket 12 and a voltage regulator 13, wherein the cable terminal to be tested 8 is a GIS cable terminal, and the cable terminal to be tested 9 is an outdoor cable terminal.

[0083] The loop 1 is used to connect the terminal of the cable to be tested and is arranged in the experimental chamber 3. The through-hole transformer 2 passes through the loop 1 and the power is set by the voltage regulator 13 controlled by the current controller 4 to load different currents to the loop 1. The current setting range can be 0~1800A. The temperature in the experimental chamber 3 is controlled by the temperature controller 5, which controls the temperature regulator 6 to cool the experimental chamber 3 and performs feedback adjustment through the target temperature sensor 7.

[0084] The sensors include temperature sensors and pressure sensors, which are used to detect the test data between two adjacent structural layers of the cable terminal to be tested 8 or the cable terminal to be tested 9. The temperature sensor includes a T-type temperature sensor 14 and a target temperature sensor 7, wherein the T-type temperature sensor 14 is arranged at different structural layers of the cable terminal to be tested, and the target temperature sensor 7 is arranged inside the experimental cabin 3. The pressure sensor includes a pressure sensor 15, which is arranged at different structural layers of the cable terminal to be tested.

[0085] The solid-solid interface and the oil-solid interface inside the cable terminal to be tested need to be insulated, and sensors can be used to capture the insulation matching of the above interfaces. At the same time, multiple temperature and pressure sensors are also arranged at different positions on the same interface to approximate the continuous temperature-stress distribution of the entire interface.

[0086] Data collection can be achieved through an acquisition card, a data acquisition host computer and a temperature controller 5. The lead wires of each temperature sensor 14 and pressure sensor 15 are connected to the data acquisition host computer through an acquisition card, and the target temperature sensor 7 communicates with the temperature controller 5.

[0087] The controller is used to determine the predetermined current to be passed into the circuit where the cable terminal to be tested is located during the predetermined period of time according to the relationship between time and electric load, and input a current adjustment instruction to the current regulator based on the predetermined current; it is used to determine the predetermined external temperature of the cable terminal to be tested during the predetermined period of time according to the relationship between time and air temperature, and input a temperature adjustment instruction to the temperature regulator based on the predetermined external temperature; it is also used to receive test data sent by the sensor, and obtain heat and stress test results of the cable terminal to be tested based on multiple different test data.

[0088] The current regulator is used for regulating a predetermined current flowing into the loop in response to a current regulation instruction.

[0089] The temperature regulator is used to adjust the cable terminal to be tested or the cable terminal to be tested to a predetermined external temperature in response to a temperature adjustment instruction.

[0090] According to an embodiment of the present invention, by setting a loop and setting the cable terminal 8 and the cable terminal 9 to be tested in the loop, the cable terminals to be tested of different terminal types can be set in the same loop, so that the simulation test of the cable terminals to be tested of different terminal types can be realized by controlling the loop and the temperature in an area, which can improve the efficiency of the test. In addition, by analyzing through the controller, and inputting the current adjustment instruction and the temperature adjustment instruction respectively, controlling the current regulator and the temperature regulator to adjust the cable terminal to be tested, the simulation can be accurately performed, and the accuracy of the test can be improved.

[0091] According to an embodiment of the present invention, the cable terminal to be tested includes multiple different types, and the high-voltage cable terminal thermal-mechanical stress monitoring system under extreme cold environment also includes: an experimental cabin, wherein at least one target temperature sensor matching the cable terminal to be tested is arranged in the experimental cabin; the distance between the cable terminal to be tested and the at least one target temperature sensor is less than a predetermined distance threshold.

[0092] According to an embodiment of the present invention, the distance between the target temperature sensor in the experimental chamber and the cable terminal to be tested is less than a predetermined spacing threshold to ensure that the temperature collected by the target temperature sensor is sufficiently close to the actual ambient temperature of the cable terminal to be tested, wherein the predetermined spacing threshold can be 1 meter.

[0093] According to an embodiment of the present invention, by controlling the distance between the cable terminal to be tested and the target temperature sensor to be less than a predetermined distance threshold, the temperature collected by the target temperature sensor can be made sufficiently close to the actual ambient temperature of the cable terminal to be tested, thereby judging the relationship between the ambient temperature of the cable terminal to be tested and the predetermined external temperature, so that when the ambient temperature is different from the predetermined external temperature, a temperature adjustment instruction can be promptly issued through the controller so that the cable terminal to be tested is at the predetermined external temperature, thereby enhancing the simulation effect and further improving the accuracy of thermal-mechanical stress monitoring of high-voltage cable terminals in extremely cold environments.

[0094] According to an embodiment of the present invention, the regulating capacity of the temperature regulator is greater than the maximum temperature variation in the relationship between time and air temperature.

[0095] According to an embodiment of the present invention, the maximum temperature change in the relationship between time and air temperature can be determined based on the maximum value of the temperature change within a predetermined time. In order to enable the temperature regulator to control the cable terminal to be tested to be at a predetermined external temperature, the adjustment capacity of the temperature regulator needs to be greater than the maximum temperature change. The adjustment capacity of the temperature regulator can be set to a maximum cooling rate of 20°C / h and a minimum cooling rate of -30°C.

[0096] According to an embodiment of the present invention, by ensuring the adjustment capability of the temperature regulator, it is possible to control the terminal to be tested to be at a predetermined external temperature using the temperature regulator, thereby ensuring the accuracy of the simulation environment and further improving the accuracy of thermal-mechanical stress monitoring of high-voltage cable terminals in extremely cold environments.

[0097] Figure 3 A schematic diagram of sensor locations of a GIS cable terminal according to an embodiment of the present invention is shown.

[0098] like Figure 3 As shown, the temperature sensor 14 and the pressure sensor 15 in the GIS cable terminal can be respectively arranged between the cable insulation layer and the stress cone root, the cable insulation layer and the stress cone middle, the cable insulation layer and the stress cone head, the stress cone root and the epoxy interface layer, the stress cone middle and the epoxy interface layer, and the stress cone head and the epoxy interface layer. Among them, a group of temperature sensors 14 and pressure sensors 15 are arranged on every two adjacent structural layers, and the same group of temperature sensors and pressure sensors are arranged on the same circumference and are 180° apart.

[0099] Figure 4 A schematic diagram showing sensor locations of an outdoor cable terminal according to an embodiment of the present invention is shown.

[0100] like Figure 4 As shown, the temperature sensor 14 and the pressure sensor 15 of the outdoor cable terminal can be respectively arranged at the cable insulation layer and the root of the stress cone, the cable insulation layer and the middle of the stress cone, and the cable insulation layer and the head of the stress cone. Among them, a group of temperature sensors 14 and pressure sensors 15 are arranged on every two adjacent structural layers, and the same group of temperature sensors and pressure sensors are arranged on the same circumference and are 180° apart. In addition, a plurality of temperature sensors 14 and pressure sensors 15 can be installed at multiple positions on the root, middle, head of the stress cone surface and the cable insulation layer surface.

[0101] Figure 5 A block diagram of an electronic device suitable for implementing a method for monitoring thermal-mechanical stress of a high-voltage cable terminal in an extreme cold environment according to an embodiment of the present invention is shown.

[0102] like Figure 5As shown, the electronic device 500 according to an embodiment of the present invention includes a processor 501, which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM) 502 or a program loaded from a storage part 508 to a random access memory (RAM) 503. The processor 501 may include, for example, a general-purpose microprocessor (such as a CPU), an instruction set processor and / or a related chipset and / or a special-purpose microprocessor (for example, an application-specific integrated circuit (ASIC)), etc. The processor 501 may also include an onboard memory for caching purposes. The processor 501 may include a single processing unit or multiple processing units for performing different actions of the method flow according to an embodiment of the present invention.

[0103] In RAM 503, various programs and data required for the operation of electronic device 500 are stored. Processor 501, ROM 502 and RAM 503 are connected to each other via bus 504. Processor 501 performs various operations of the method flow according to the embodiment of the present invention by executing the program in ROM 502 and / or RAM 503. It should be noted that the program can also be stored in one or more memories other than ROM 502 and RAM 503. Processor 501 can also perform various operations of the method flow according to the embodiment of the present invention by executing the program stored in the one or more memories.

[0104] According to an embodiment of the present invention, the electronic device 500 may further include an input / output (I / O) interface 505, which is also connected to the bus 504. The electronic device 500 may further include one or more of the following components connected to the I / O interface 505: an input portion 506 including a keyboard, a mouse, etc.; an output portion 507 including a cathode ray tube (CRT), a liquid crystal display (LCD), etc., and a speaker, etc.; a storage portion 508 including a hard disk, etc.; and a communication portion 509 including a network interface card such as a LAN card, a modem, etc. The communication portion 509 performs communication processing via a network such as the Internet. A drive 510 is also connected to the I / O interface 505 as needed. A removable medium 511, such as a magnetic disk, an optical disk, a magneto-optical disk, a semiconductor memory, etc., is installed on the drive 510 as needed, so that a computer program read therefrom is installed into the storage portion 508 as needed.

[0105] The present invention also provides a computer-readable storage medium, which may be included in the device / apparatus / system described in the above embodiment; or may exist independently without being assembled into the device / apparatus / system. The above computer-readable storage medium carries one or more programs, and when the above one or more programs are executed, the method according to the embodiment of the present invention is implemented.

[0106] According to an embodiment of the present invention, the computer-readable storage medium may be a non-volatile computer-readable storage medium, for example, may include but is not limited to: a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof. In the present invention, the computer-readable storage medium may be any tangible medium containing or storing a program, which may be used by or in combination with an instruction execution system, an apparatus or a device. For example, according to an embodiment of the present invention, the computer-readable storage medium may include the ROM 502 and / or RAM 503 described above and / or one or more memories other than ROM 502 and RAM 503.

[0107] The embodiment of the present invention also includes a computer program product, which includes a computer program, and the computer program contains program code for executing the method shown in the flowchart. When the computer program product is run in a computer system, the program code is used to enable the computer system to implement the method for monitoring thermal-mechanical stress of high-voltage cable terminals in extreme cold environments provided by the embodiment of the present invention.

[0108] The computer program executes the above functions defined in the system / device of the embodiment of the present invention when it is executed by the processor 501. According to the embodiment of the present invention, the system, device, module, unit, etc. described above can be implemented by a computer program module.

[0109] In one embodiment, the computer program may rely on tangible storage media such as optical storage devices, magnetic storage devices, etc. In another embodiment, the computer program may also be transmitted and distributed in the form of signals on a network medium, and downloaded and installed through the communication part 509, and / or installed from the removable medium 511. The program code contained in the computer program may be transmitted using any appropriate network medium, including but not limited to: wireless, wired, etc., or any suitable combination of the above.

[0110] In such an embodiment, the computer program can be downloaded and installed from the network through the communication part 509, and / or installed from the removable medium 511. When the computer program is executed by the processor 501, the above functions defined in the system of the embodiment of the present invention are performed. According to the embodiment of the present invention, the system, device, means, module, unit, etc. described above can be implemented by a computer program module.

[0111] According to an embodiment of the present invention, the program code for executing the computer program provided by the embodiment of the present invention can be written in any combination of one or more programming languages. Specifically, these computing programs can be implemented using high-level process and / or object-oriented programming languages, and / or assembly / machine languages. Programming languages ​​include, but are not limited to, Java, C++, python, "C" language or similar programming languages. The program code can be executed entirely on the user computing device, partially on the user device, partially on the remote computing device, or entirely on the remote computing device or server. In the case of a remote computing device, the remote computing device can be connected to the user computing device through any type of network, including a local area network (LAN) or a wide area network (WAN), or can be connected to an external computing device (e.g., using an Internet service provider to connect through the Internet).

[0112] The flow chart and block diagram in the accompanying drawings illustrate the possible architecture, function and operation of the system, method and computer program product according to various embodiments of the present invention. In this regard, each box in the flow chart or block diagram can represent a module, a program segment, or a part of a code, and the above-mentioned module, program segment, or a part of a code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram or flow chart, and the combination of the boxes in the block diagram or flow chart can be implemented with a dedicated hardware-based system that performs a specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

[0113] It will be appreciated by those skilled in the art that the features described in the various embodiments and / or claims of the present invention may be combined and / or combined in various ways, even if such combinations and / or combinations are not explicitly described in the present invention. In particular, the features described in the various embodiments and / or claims of the present invention may be combined and / or combined in various ways without departing from the spirit and teachings of the present invention. All of these combinations and / or combinations fall within the scope of the present invention.

[0114] The embodiments of the present invention are described above. However, these embodiments are only for the purpose of illustration, and are not intended to limit the scope of the present invention. Although each embodiment is described above, it does not mean that the measures in each embodiment cannot be used in combination. The scope of the present invention is defined by the attached claims and their equivalents. Without departing from the scope of the present invention, those skilled in the art may make various substitutions and modifications, which should all fall within the scope of the present invention.

Claims

1. A method for monitoring thermal-mechanical stress of high-voltage cable terminals in an extremely cold environment, characterized in that: The method comprises: According to the relationship between time and electric load, a predetermined current is passed into the loop where the terminal of the cable to be tested is located in a predetermined period of time, wherein the relationship between time and electric load is obtained by processing the actual electric load current carrying capacity data at the predetermined geographical location; According to the relationship between time and temperature, adjusting the external environment of the cable terminal to be tested to a predetermined external temperature during the predetermined period, wherein the relationship between time and temperature is obtained by processing the real environment data of the predetermined geographical location; Under the conditions of the predetermined current and the predetermined external temperature, acquiring test data between two adjacent structural layers of the cable terminal to be tested, wherein the test data includes a plurality of test sub-data located at different length positions of the cable terminal to be tested, and each of the test sub-data includes temperature data and pressure data; and Based on the different test data, obtaining the heat and stress test results of the cable terminal to be tested; Wherein, the step of obtaining the test data between two adjacent structural layers of the cable terminal to be tested includes: Determining the terminal type of the cable terminal to be tested; and Using pressure sensors and temperature sensors disposed at multiple different terminal test positions, a plurality of the test sub-data are acquired to obtain the test data, wherein the terminal test position includes a position between the two adjacent structural layers that matches the terminal type, and the two adjacent structural layers include a cable insulation layer and a stress cone and / or a stress cone and an epoxy interface layer; The step of obtaining the heat and stress test results of the cable terminal to be tested based on the different test data includes: Based on the plurality of test data, obtaining the temperature and pressure variation curves of the respective two adjacent structural layers of the cable terminal to be tested over time; and Based on the temperature and pressure variation curves over time, obtaining the heat and stress test results of the cable terminal to be tested; The method further comprises: Determining a plurality of different terminal test positions of the cable terminal to be tested based on the terminal type of the cable terminal to be tested, wherein the terminal test positions include a terminal pressure test position and a terminal temperature test position, and the terminal pressure test position and the terminal temperature test position of the same group are on the same circumference of the cable terminal to be tested and are 180° apart; and The pressure sensor and the temperature sensor are respectively arranged at a plurality of the terminal test positions.

2. The method according to claim 1, characterized in that Using pressure sensors and temperature sensors disposed at multiple different terminal test positions, a plurality of test sub-data are acquired, including: Acquiring a plurality of initial test sub-data using pressure sensors and temperature sensors disposed at a plurality of different terminal test positions; and In the case that the pressure change value of the pressure data in each of the initial test sub-data within a predetermined pressure change period is less than the predetermined pressure threshold, and in the case that the temperature change value of the temperature data in each of the initial test sub-data within a predetermined temperature change period is less than the predetermined temperature threshold, the test sub-data is obtained based on the initial test sub-data.

3. The method according to claim 1, characterized in that The method of supplying a predetermined current to the circuit where the cable terminal to be tested is located in a predetermined period of time according to the relationship between time and electric load includes: Determining the amount of change in the electric load at the predetermined geographical location within the predetermined period of time according to the relationship between the time and the electric load; and Based on the change in the electric load, a voltage regulator is used to adjust the input power of the through-hole transformer configured in the loop until the predetermined current flows in the loop within the predetermined time period.

4. The method according to claim 1, characterized in that: The step of adjusting the external environment of the cable terminal to be tested to a predetermined external temperature during the predetermined period according to the relationship between time and air temperature includes: Determining the temperature difference of the predetermined geographical location within the predetermined period of time according to the relationship between the time and the temperature; and Based on the temperature difference, the environment inside the test chamber where the loop of the cable terminal to be tested is located is adjusted to the predetermined external temperature.

5. A system for monitoring thermal-mechanical stress of high-voltage cable terminals in extreme cold environments, applied to the method for monitoring thermal-mechanical stress of high-voltage cable terminals in extreme cold environments as claimed in any one of claims 1 to 4, characterized in that: The system comprises: A loop, wherein the loop is used to connect the terminal of the cable to be tested; A sensor, used for detecting test data between two adjacent structural layers of the cable terminal to be tested; The controller is used to determine the predetermined current to be passed into the circuit where the cable terminal to be tested is located during the predetermined period of time according to the relationship between time and electric load, and input a current adjustment instruction to the current regulator based on the predetermined current; to determine the predetermined external temperature of the cable terminal to be tested during the predetermined period of time according to the relationship between time and air temperature, and input a temperature adjustment instruction to the temperature regulator based on the predetermined external temperature; and to receive the test data sent by the sensor, and obtain the heat and stress test results of the cable terminal to be tested based on different multiple test data; a current regulator, configured to adjust the predetermined current flowing into the loop in response to the current adjustment instruction; and A temperature regulator, for regulating the cable terminal to be tested to the predetermined external temperature in response to the temperature adjustment instruction; Wherein, the detecting of the test data between two adjacent structural layers of the cable terminal to be tested comprises: Determining the terminal type of the cable terminal to be tested; and Using pressure sensors and temperature sensors disposed at multiple different terminal test positions, a plurality of the test sub-data are acquired to obtain the test data, wherein the terminal test position includes a position between the two adjacent structural layers that matches the terminal type, and the two adjacent structural layers include a cable insulation layer and a stress cone and / or a stress cone and an epoxy interface layer; The step of obtaining the heat and stress test results of the cable terminal to be tested based on the different test data includes: Based on the plurality of test data, obtaining the temperature and pressure variation curves of the respective two adjacent structural layers of the cable terminal to be tested over time; and Based on the temperature and pressure variation curves over time, obtaining the heat and stress test results of the cable terminal to be tested; The controller is also used for: Determining a plurality of different terminal test positions of the cable terminal to be tested based on the terminal type of the cable terminal to be tested, wherein the terminal test positions include a terminal pressure test position and a terminal temperature test position, and the terminal pressure test position and the terminal temperature test position of the same group are on the same circumference of the cable terminal to be tested and are 180° apart; and The pressure sensor and the temperature sensor are respectively arranged at a plurality of the terminal test positions.

6. The system according to claim 5, characterized in that The cable terminals to be tested include multiple different types, The system further comprises: An experimental chamber, wherein at least one target temperature sensor matching the cable terminal to be tested is provided in the experimental chamber; The distance between the cable terminal to be tested and the at least one target temperature sensor is smaller than a predetermined distance threshold.

7. The system according to claim 5, characterized in that The regulating capacity of the temperature regulator is greater than the maximum temperature change in the relationship between time and air temperature.

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