An automatic control device and testing method for high-voltage cable aluminum conductor loop

Abstract

The application provides an automatic control device and a test method for a high-voltage cable aluminum conductor loop. The device comprises a test circuit module, a voltage regulator, a strong current control box, a manual weak current control box, and a wireless connected control module. The test circuit module includes a high-voltage cable aluminum conductor, a terminal terminal, an aluminum connecting pipe, a core-penetrating transformer, a current transformer, an acquisition box, and temperature and current acquisition wires. The acquisition box integrates LoRa wireless communication, temperature and current acquisition modules, and synchronously monitors the conductor and connection point temperature through a double probe structure. The test method determines the reference temperature θ R by first thermal cycling, then performs multiple automatic thermal cycles, maintains the temperature within θ R ±2℃ by adjusting the current, and sets the shortest heating time based on the conductor cross-sectional area. The application relates to the technical field of power equipment detection and is specifically applied to the intelligent test of distribution switch control equipment and cable accessories in the smart grid industry.

Description

Technical Field

[0001] This invention relates to the field of power equipment testing technology, and is specifically applied to the intelligent testing of distribution switch control equipment and cable accessories in the smart grid industry, particularly to an automated control device and testing method for aluminum conductor circuits of high-voltage cables. Background Technology

[0002] In the construction of smart grids, cross-linked polyethylene insulated power cables and their accessories (such as conductor connecting pipes) are the foundation for the reliable operation of power distribution systems. Conducting tests on these key components in accordance with actual dynamic operating conditions is an important requirement for ensuring the safety of smart grids and realizing intelligent status monitoring.

[0003] In the application of high-voltage power cables, especially aluminum conductor cables, ensuring the reliability of their connection circuits is crucial. In the existing technology, the inspection of fittings such as aluminum conductor connecting tubes mainly relies on a series of basic inspection methods, such as appearance and size inspection, material inspection, trial assembly matching inspection, crimping morphology inspection, and DC resistance test. These methods constitute the main technical means for evaluating the initial state and quality compliance of connecting components.

[0004] However, these existing testing methods are essentially static testing methods. For example, DC resistance testing can only provide a "static snapshot" of the connection point at the moment of testing. In actual operation, cables will be subjected to the thermal cycling effect caused by changes in load current for a long time. There is a risk of connection point deterioration due to dynamic factors such as moving, cable creep, thermal expansion and contraction. Static testing cannot effectively simulate and evaluate such long-term dynamic effects, and therefore it is difficult to detect potential connection defects. These defects may cause hot spots due to excessive local resistance during long-term operation, which in turn can lead to increased conductor resistance, material creep, accelerated insulation aging, and even the potential for cable material combustion and fire, seriously threatening the long-term operational safety of power cable lines.

[0005] Therefore, the inventors urgently need an automated control device and testing method for the aluminum conductor circuit of a high-voltage cable that can simulate actual dynamic operating conditions and be automatically executed to solve the above problems. Summary of the Invention

[0006] To address the shortcomings of the prior art, this invention provides an automated control device and testing method for aluminum conductor circuits of high-voltage cables. The aim is to solve the technical problem in the smart grid field where existing technologies cannot effectively simulate and evaluate the thermal cycling and dynamic stress experienced by aluminum conductor connection circuits of high-voltage cables during actual long-term operation through static testing, thus making it difficult to predict potential connection defects and overheating risks.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is: an automated control device for a high-voltage cable aluminum conductor circuit, comprising a test circuit module, a voltage regulator electrically connected to the test circuit module, a high-voltage control box electrically connected to the voltage regulator, a manually controlled low-voltage box, and a control module wirelessly connected to the test circuit module and the manually controlled low-voltage box respectively. The test circuit module includes a high-voltage cable aluminum conductor, terminal terminals connected to both ends of the high-voltage cable aluminum conductor to form a closed loop, a plurality of aluminum connecting tubes uniformly distributed and pressed onto the high-voltage cable aluminum conductor, a plurality of through-core transformers sleeved on the high-voltage cable aluminum conductor, a current transformer sleeved on the high-voltage cable aluminum conductor, a data acquisition box, and a plurality of temperature acquisition wires and current acquisition wires. The plurality of through-core transformers are connected in parallel to each other and electrically connected to the voltage regulator. The data acquisition box is electrically connected to the current transformer through the current acquisition wires. The data acquisition box is electrically connected to the high-voltage cable aluminum conductor, the aluminum connecting tubes, and the terminal terminals respectively through the plurality of temperature acquisition wires for monitoring their temperature.

[0008] Based on the above, the beneficial effect of an automated control device for high-voltage cable aluminum conductor circuits is that it solves the technical problem in the field of smart grids where existing technologies cannot effectively simulate and evaluate the thermal cycling and dynamic stress experienced by high-voltage cable aluminum conductor connection circuits during actual long-term operation through static testing, thus making it difficult to predict potential connection defects and overheating risks; this is mainly reflected in:

[0009] 1. This invention simulates the electrical connection and physical structure of a real high-voltage cable line by forming a closed loop consisting of an aluminum conductor, terminal terminal and aluminum connecting pipe of a high-voltage cable. It realizes the reproduction of actual operating conditions in an experimental environment and provides a real carrier and target object for applying dynamic thermal cycle stress.

[0010] 2. This invention connects the core transformer and the voltage regulator via electrical signals, and applies a precisely adjustable large AC current to the aluminum conductor of the high-voltage cable according to control commands. This enables repeated and controllable heating of the test circuit from room temperature to high temperature, thereby simulating the thermal cycling process of the aluminum conductor of the high-voltage cable caused by load changes in actual operation, and replacing the DC resistance test in the prior art.

[0011] 3. This invention connects temperature acquisition wires and current acquisition wires to the aluminum conductor, aluminum connecting pipe, terminal terminal, and current transformer of the high-voltage cable, respectively. During the test, the temperature and current parameters at key locations in the circuit are monitored in real time, realizing dynamic data acquisition of multiple points and parameters throughout the thermal cycle. This provides a data basis for discovering local overheating points and connection defects that cannot be shown in static tests.

[0012] 4. This invention achieves intelligent closed-loop control and unmanned operation of the entire thermal cycling test process by wirelessly connecting the control module, test circuit module, and manual control low-voltage box, and working in conjunction with the voltage regulator. Based on real-time collected temperature and current data, it automatically adjusts the output of the voltage regulator. This meets the operation and maintenance requirements of intelligent power distribution systems, significantly improving test efficiency and consistency, and enabling safe and reliable execution of long-term cyclic tests. It also provides early warning of potential connection defects and overheating risks, enhancing the proactive safety capabilities of intelligent power grid distribution systems.

[0013] Furthermore, the end of the temperature acquisition wire is provided with a first probe and a second probe, wherein the first probe is used to contact the surface of the aluminum connecting tube or terminal terminal to measure the temperature, and the second probe is used to contact the surface of the aluminum conductor of the high-voltage cable to measure the temperature.

[0014] Based on the above, the beneficial effect of the first probe is that it can directly measure the temperature of the surface in contact with the aluminum connecting tube or terminal, realizing directional temperature monitoring of key connection points in the cable circuit, and providing key data for evaluating crimping quality and timely detection of the risk of overheating of connection points due to increased contact resistance; the beneficial effect of the second probe is that it can directly measure the temperature of the aluminum conductor in contact with the high-voltage cable, realizing independent monitoring of the conductor body temperature as the temperature rise control reference, providing the core feedback signal for the entire automated control loop, and ensuring the accuracy and reliability of the temperature control reference in thermal cycling tests.

[0015] Furthermore, the data acquisition box includes an outer shielded aluminum box, a shielding cover that mates with the outer shielded aluminum box, a LoRa wireless communication module, a temperature acquisition module, a current acquisition module, and a current transmitter disposed within the outer shielded aluminum box, a filter and isolation transformer composite socket disposed outside the outer shielded aluminum box, and several K-type connectors and current sockets. The temperature acquisition module is electrically connected to the temperature acquisition wire via the K-type connector, the current transmitter is electrically connected to the current acquisition wire via the current socket, the current acquisition module is electrically connected to the current transmitter, and both the temperature acquisition module and the current acquisition module are electrically connected to the LoRa wireless communication module. A filter and isolation transformer is plugged into the filter and isolation transformer composite socket, and an antenna electrically connected to the LoRa wireless communication module is disposed on the shielding cover.

[0016] Based on the above, the beneficial effects of the outer shielded aluminum box are as follows: It encapsulates the internal LoRa wireless communication module, temperature acquisition module, current acquisition module, and current transmitter, achieving electromagnetic shielding and physical protection for core electronic components. This effectively resists strong electromagnetic interference generated during the operation of components such as through-core transformers, ensuring the stability of data acquisition and transmission. The beneficial effects of the LoRa wireless communication module are that it receives signals from the temperature and current acquisition modules and transmits them wirelessly, enabling remote wireless communication between the acquired data and the control module. This disconnects the direct electrical connection between the high-voltage testing area and the low-voltage control equipment, fundamentally avoiding the risk of high-voltage breakdown and ensuring the safety of personnel and equipment. The beneficial effects of the temperature acquisition module are that it receives and processes temperature signals from the first and second probes, achieving high-precision and parallel acquisition of multi-point temperatures of the high-voltage cable's aluminum conductor, aluminum connecting pipe, and terminal terminals, providing accurate temperature feedback for automated control. The benefits of the current acquisition module are that it receives and processes current signals from the current transformer, enabling real-time monitoring of the current parameters in the test circuit and providing crucial electrical parameter data for analyzing heating power and system load. The benefits of the current transmitter are that it safely and accurately converts large current signals into standardized signals that the current acquisition module can process, enhancing measurement safety and anti-interference capabilities. The benefits of the filter and isolation transformer composite socket are that it allows for the plugging and installation of filter and isolation transformers. The benefits of the K-type connector are that this connector is used for quick and reliable connection between the temperature acquisition wires and the temperature acquisition module, achieving low-loss and high-reliability transmission of K-type thermocouple signals, ensuring the ease of connection and signal accuracy of the temperature measurement link. The benefits of the current socket are that it allows for quick and reliable connection between the current acquisition wires and the current transmitter, enabling convenient plugging and unplugging of current signals and stable transmission, ensuring the connection reliability and operational convenience of the current measurement circuit.

[0017] Furthermore, the number of the core-through transformers is three, and they are connected in parallel.

[0018] Furthermore, the control module includes a computer system that communicates with the test circuit module and the manual control low-voltage box via LoRa wireless communication. The computer system is used to collect temperature and current data in real time and automatically adjust the output voltage and current of the voltage regulator according to preset parameters.

[0019] Based on the above, the beneficial effect of the computer system in real-time acquisition of temperature and current data is that by continuously acquiring the key state parameters of the test circuit module, it achieves accurate capture and recording of the dynamic changes throughout the thermal cycling test, providing complete data basis for subsequent analysis, control and report generation.

[0020] Furthermore, the high-voltage control box includes overcurrent protectors and overvoltage protectors for circuit protection.

[0021] Furthermore, the manual control low-voltage box includes a manual control module and an automatic control module. The manual control module is used to manually adjust the voltage regulator, and the automatic control module is wirelessly connected to the control module to realize dual control functions.

[0022] Furthermore, the voltage regulator has an output voltage range of 2V to 420V to simulate different operating conditions of the cable.

[0023] Furthermore, the present invention also provides a testing method for an automated control device for a high-voltage cable aluminum conductor circuit, comprising the following steps:

[0024] S1. Conduct the first thermal cycling test: Apply alternating current to the core transformer through the voltage regulator to heat the aluminum conductor of the high-voltage cable, and monitor the temperature of the aluminum conductor of the high-voltage cable through the second probe of the temperature acquisition wire, and monitor the temperature of the aluminum connecting tube through the first probe;

[0025] S2. When the temperature of the aluminum conductor of the high-voltage cable reaches the first stable state as detected by the second probe, the temperature of the aluminum conductor of the high-voltage cable is recorded as θ. R The first stable state refers to the temperature change range of the aluminum conductor of the high-voltage cable within ±2℃ within 15 minutes.

[0026] S3. Under the first stable state, obtain the intermediate temperature value of the aluminum connecting tube based on the monitoring data of the first probe;

[0027] S4. If the median temperature of the aluminum connecting pipe is greater than or equal to 100℃, record the current temperature of the aluminum conductor of the high-voltage cable as θ. R The second thermal cycle test begins. If the median temperature of the aluminum connecting pipe is less than 100°C, the control module controls the voltage regulator to increase the loop current until the median temperature of the aluminum connecting pipe reaches 100°C, and the temperature of the high-voltage cable aluminum conductor is less than or equal to 140°C, or only the temperature of the high-voltage cable aluminum conductor reaches 140°C. The current temperature of the high-voltage cable aluminum conductor is recorded as θ. R The second thermal cycling test was then initiated.

[0028] S5. Conduct a second thermal cycling test: Apply alternating current through the voltage regulator to heat the aluminum conductor of the high-voltage cable to θ. R And record from the start of heating until the temperature reaches θ R The required heating time t1, and the required cooling time t2 to subsequently cool to below 35°C;

[0029] S6. Conduct multiple thermal cycle tests: Using the heating time t1 and cooling time t2 as the period, conduct multiple thermal cycles;

[0030] S7. During the thermal cycling test, temperature and current data are monitored in real time using the temperature and current acquisition wires, and the voltage regulator is automatically adjusted by the control module to maintain the temperature of the aluminum conductor of the high-voltage cable at θ. R Within ±2℃ range;

[0031] S8. All monitoring data are transmitted to the control module via the LoRa wireless communication module, and a test report is generated based on the collected data.

[0032] Based on the above, the beneficial effects of step S1 are as follows: First heating is achieved by applying AC current through the voltage regulator and the core transformer, and the temperatures of the aluminum connecting tube and the aluminum conductor of the high-voltage cable are simultaneously monitored using the first and second probes. This realizes the synchronous acquisition of the initial temperature rise and the temperature of key parts of the test circuit, establishing a data foundation for subsequent determination of control parameters. The beneficial effects of step S2 are the accurate calibration and quantitative recording of the test reference temperature, ensuring the accuracy of the temperature control target throughout the test process. The beneficial effects of step S3 are that, under the first stable state, the intermediate temperature value of the aluminum connecting tube is obtained based on the monitoring data of the first probe, realizing the central trend analysis of temperature data from multiple connection points, providing a core criterion for objectively evaluating the overall heating status of the connection points. The beneficial effects of step S4 are that, based on the intermediate temperature value of the aluminum connecting tube, appropriate operations are performed: if the temperature is insufficient, [further steps are taken]. By increasing the loop current through the control module and setting dual termination conditions (100°C for the aluminum connecting tube or 140°C for the aluminum conductor of the high-voltage cable), adaptive enhancement of test conditions and safety boundary control are achieved, ensuring the rigor of the test and the safety of the equipment. The beneficial effect of step S5 is the accurate determination of key time parameters for a single complete thermal cycle, setting a standard period for subsequent accelerated aging cycle tests. The beneficial effect of step S6 is that by using the measured heating time t1 and cooling time t2 as a fixed period for multiple thermal cycles, the "time compression" effect of simulating years or even decades of thermal fatigue aging of the cable connection loop within several days or weeks is achieved, greatly improving the verification efficiency of long-term operational stability. The beneficial effect of step S7 is that by continuously monitoring data during the cycle and automatically adjusting the voltage regulator through the control module to maintain the temperature of the aluminum conductor of the high-voltage cable at θ R Within a range of ±2℃, fully automated closed-loop control and high-precision temperature control of the thermal cycling process were achieved, ensuring the stability and consistency of test conditions and the repeatability of results. The beneficial effect of step S8 is that all monitoring data are transmitted to the control module through the LoRa wireless communication module and a test report is generated, realizing wireless and remote aggregation of test data and automated report generation.

[0033] Furthermore, in step S6, the heating time t1 is greater than or equal to the minimum heating time specified based on the nominal cross-sectional area of ​​the conductor, wherein,

[0034] When 16 mm² < nominal conductor cross-sectional area ≤ 50 mm², the shortest heating time is ≥ 5 min;

[0035] When 50 mm² < nominal conductor cross-sectional area ≤ 150 mm², the shortest heating time is ≥ 10 min;

[0036] When 150 mm² < nominal conductor cross-sectional area ≤ 630 mm², the shortest heating time is ≥ 15 min;

[0037] When the nominal cross-sectional area of ​​the conductor is greater than 630 mm², the shortest heating time is ≥20 min.

[0038] Based on the above, the beneficial effect of limiting the heating time t1 in step S6 to be greater than or equal to the minimum heating time specified based on the nominal cross-sectional area of ​​the conductor is that by setting differentiated minimum heating time thresholds for conductors of different specifications, it ensures that the heat energy applied to the test circuit is sufficiently accumulated, effectively simulating the characteristics of large cross-section conductors with large thermal inertia and slow temperature rise in actual operation, preventing the decrease in test severity due to insufficient heating, thereby ensuring the effectiveness of accelerated thermal aging test and the comparability of test results for cables of different specifications.

[0039] To make the above features of the present invention and the objectives to be achieved clearer, the present invention will be further described below in conjunction with the accompanying drawings and specific embodiments. Attached Figure Description

[0040] Figure 1 : This is a schematic diagram of the circuit connection of the present invention;

[0041] Figure 2 : This is a schematic diagram of the test circuit module of the present invention;

[0042] Figure 3 : This is an exploded view of the collection box of the present invention;

[0043] Figure 4 : This is a schematic diagram of the temperature acquisition wire of the present invention;

[0044] Figure 5 : This is a flowchart illustrating the testing method of the present invention.

[0045] Explanation of reference numerals: 1-Test circuit module, 11-High voltage cable aluminum conductor, 12-Terminal terminal, 13-Aluminum connecting pipe, 14-Through-core transformer, 15-Current transformer, 16-Acquisition box, 161-Outer shielded aluminum box, 162-LoRa wireless communication module, 163-Temperature acquisition module, 164-Current acquisition module, 165-Current transmitter, 166-Filter and isolation transformer composite socket, 167-K-type connector, 168-Current socket, 169-Shielding cover, 1691-Antenna, 17-Temperature acquisition wire, 171-First probe, 172-Second probe, 18-Current acquisition wire, 2-Voltage regulator, 3-High voltage control box, 4-Manual control low voltage box, 5-Control module. Detailed Implementation

[0046] like Figures 1-5 As shown, an automated control device for a high-voltage cable aluminum conductor circuit includes a test circuit module 1, a voltage regulator 2 electrically connected to the test circuit module 1, a high-voltage control box 3 electrically connected to the voltage regulator 2, a manually controlled low-voltage box 4, and a control module 5 wirelessly connected to the test circuit module 1 and the manually controlled low-voltage box 4, respectively. The test circuit module 1 includes a high-voltage cable aluminum conductor 11, terminal terminals 12 connected to both ends of the high-voltage cable aluminum conductor 11 to form a closed circuit, a plurality of aluminum connecting tubes 13 evenly distributed and pressed onto the high-voltage cable aluminum conductor 11, and a sleeved on the high-voltage cable... The high-voltage cable aluminum conductor 11 includes several through-core transformers 14, current transformers 15 sleeved on the high-voltage cable aluminum conductor 11, a data acquisition box 16, and several temperature acquisition wires 17 and current acquisition wires 18. The through-core transformers 14 are connected in parallel to each other and are electrically connected to the voltage regulator 2. The data acquisition box 16 is electrically connected to the current transformer 15 through the current acquisition wires 18. The data acquisition box 16 is electrically connected to the high-voltage cable aluminum conductor 11, the aluminum connecting pipe 13, and the terminal terminal 12 through several temperature acquisition wires 17, respectively, for monitoring their temperature.

[0047] In this embodiment, the end of the temperature acquisition wire 17 is provided with a first probe 171 and a second probe 172, wherein the first probe 171 is used to contact the surface of the aluminum connecting tube 13 or the terminal terminal 12 to measure the temperature, and the second probe 172 is used to contact the surface of the aluminum conductor 11 of the high-voltage cable to measure the temperature.

[0048] In this embodiment, the data acquisition box 16 includes an outer shielded aluminum box 161, a shielding cover 169 that cooperates with the outer shielded aluminum box 161, a LoRa wireless communication module 162, a temperature acquisition module 163, a current acquisition module 164, and a current transmitter 165 disposed inside the outer shielded aluminum box 161, a filter and isolation transformer composite socket 166 disposed outside the outer shielded aluminum box 161, and several K-type connectors 167 and current sockets 168. The temperature acquisition module 163 connects to the temperature acquisition module 164 through the K-type connectors 167. The current transmitter 165 is electrically connected to the current acquisition wire 18 via the current socket 168. The current acquisition module 164 is electrically connected to the current transmitter 165. The temperature acquisition module 163 and the current acquisition module 164 are both electrically connected to the LoRa wireless communication module 162. The filter and isolation transformer composite socket 166 is plugged into a filter and isolation transformer. The shielding cover 169 is provided with an antenna 1691 that is electrically connected to the LoRa wireless communication module 162.

[0049] In this embodiment, the temperature acquisition module 163 supports parallel temperature acquisition of 20 to 100 channels, and its temperature measurement accuracy can reach within ±0.5℃. It can simultaneously monitor the temperature distribution of the high-voltage cable aluminum conductor 11, all aluminum connecting pipes 13 and terminal terminals 12.

[0050] In this embodiment, the current transmitter 165 uses a through-type current transformer with a primary-side transformation ratio of 5000 / 5A as the front end, which can linearly convert a large AC current of 0-5000A into a standard DC signal of 4-20mA. Its accuracy class is 0.5 and its isolation withstand voltage class is not less than 2kV.

[0051] In this embodiment, the filter and isolation transformer that supplies power to each module in the acquisition box 16 has a stable 24V DC power supply with an output ripple ≤50mV, a load regulation rate ≤0.5%, and overcurrent, overvoltage and short circuit protection functions. The output power supports a wide range of requirements from 5-100W.

[0052] In this embodiment, there are three core transformers 14, which are connected in parallel.

[0053] In this embodiment, the control module 5 includes a computer system. The computer system communicates with the test circuit module 1 and the manual control low-voltage box 4 via LoRa wireless communication. It is used to collect temperature data and current data in real time and automatically adjust the output voltage and current of the voltage regulator 2 through preset parameters.

[0054] In this embodiment, the high-voltage control box 3 includes an overcurrent protector and an overvoltage protector for protecting the circuit.

[0055] In this embodiment, the manual control low-voltage box 4 includes a manual control module and an automatic control module. The manual control module is used to manually adjust the voltage regulator 2, and the automatic control module is wirelessly connected to the control module 5 to realize dual control functions.

[0056] In this embodiment, the output voltage range of the voltage regulator 2 is 2V to 420V, which is used to simulate different operating conditions of the cable.

[0057] This invention also discloses a testing method for an automated control device for a high-voltage cable aluminum conductor circuit, comprising the following steps:

[0058] S1. Conduct the first thermal cycling test: Apply alternating current to the core transformer 14 through the voltage regulator 2 to heat the aluminum conductor 11 of the high-voltage cable, and monitor the temperature of the aluminum conductor 11 of the high-voltage cable through the second probe 172 of the temperature acquisition wire 17, and monitor the temperature of the aluminum connecting pipe 13 through the first probe 171.

[0059] S2. When the temperature of the high-voltage cable aluminum conductor 11 reaches the first stable state as monitored by the second probe 172, the temperature of the high-voltage cable aluminum conductor 11 is recorded as θ. R The first stable state refers to the temperature change range of the aluminum conductor 11 of the high-voltage cable within ±2℃ within 15 minutes.

[0060] S3. Under the first stable state, obtain the intermediate temperature value of the aluminum connecting pipe 13 based on the monitoring data of the first probe 171;

[0061] S4. If the median temperature of the aluminum connecting pipe 13 is greater than or equal to 100°C, record the current temperature of the high-voltage cable aluminum conductor 11 as θ. R The second thermal cycle test begins. If the median temperature of the aluminum connecting pipe 13 is less than 100°C, the control module 5 controls the voltage regulator 2 to increase the loop current until the median temperature of the aluminum connecting pipe 13 reaches 100°C, and the temperature of the high-voltage cable aluminum conductor 11 is less than or equal to 140°C, or only the temperature of the high-voltage cable aluminum conductor 11 reaches 140°C. The current temperature of the high-voltage cable aluminum conductor 11 is recorded as θ. R The second thermal cycling test was then initiated.

[0062] S5. Conduct a second thermal cycle test: Apply alternating current through the voltage regulator 2 to heat the aluminum conductor 11 of the high-voltage cable to θ. R And record from the start of heating until the temperature reaches θ RThe required heating time t1, and the required cooling time t2 to subsequently cool to below 35°C;

[0063] S6. Conduct multiple thermal cycle tests: Using the heating time t1 and cooling time t2 as the period, conduct multiple thermal cycles;

[0064] S7. During the thermal cycling test, temperature and current data are monitored in real time via the temperature acquisition wire 17 and the current acquisition wire 18, and the voltage regulator 2 is automatically adjusted by the control module 5 to maintain the temperature of the aluminum conductor 11 of the high-voltage cable at θ. R Within ±2℃ range;

[0065] S8. All monitoring data are transmitted to the control module 5 via the LoRa wireless communication module 162, and a test report is generated based on the collected data.

[0066] In the first thermal cycling test of steps S1 and S2 of this embodiment, the establishment of the first stable state requires that the temperature changes of both the aluminum conductor 11 of the high-voltage cable and the aluminum connecting pipe 13 within 15 minutes be less than or equal to ±2℃, and the temperature range of the aluminum conductor 11 of the high-voltage cable is 120℃ ≤ θ. R ≤140℃.

[0067] In step S4 of this embodiment, if the intermediate temperature of the aluminum connecting tube 13 is less than 100°C, the control module 5 controls the voltage regulator 2 to increase the loop current so that the intermediate temperature of the aluminum connecting tube 13 reaches 100°C. At the same time, the upper limit of the temperature of the high-voltage cable aluminum conductor 11 is strictly controlled within 140°C, so as to achieve a balance between the severity of the test and the safety of the system.

[0068] In the multiple thermal cycle test of step S6 in this embodiment, a complete thermal cycle is defined as the sum of heating time t1 and cooling time t2. Through several such cycles, the system can effectively simulate and accelerate the reproduction of the thermal fatigue aging process experienced by the high-voltage cable aluminum conductor 11 connection circuit in actual operation over several years or even decades within a few days or weeks.

[0069] In step S6 of this embodiment, the heating time t1 is greater than or equal to the shortest heating time specified based on the nominal cross-sectional area of ​​the conductor, wherein,

[0070] When 16 mm² < nominal conductor cross-sectional area ≤ 50 mm², the shortest heating time is ≥ 5 min;

[0071] When 50 mm² < nominal conductor cross-sectional area ≤ 150 mm², the shortest heating time is ≥ 10 min;

[0072] When 150 mm² < nominal conductor cross-sectional area ≤ 630 mm², the shortest heating time is ≥ 15 min;

[0073] When the nominal cross-sectional area of ​​the conductor is greater than 630 mm², the shortest heating time is ≥20 min.

[0074] The above description is merely the optimal embodiment of the present invention and is not intended to limit the present invention. Any modifications or substitutions made by those skilled in the art without departing from the essence and scope of protection of the present invention should also be within the scope of protection of the present invention.

Claims

1. An automated control device for a high-voltage cable aluminum conductor circuit, characterized in that: The test circuit module (1) includes a test circuit module (1), a voltage regulator (2) electrically connected to the test circuit module (1), a high-voltage control box (3) electrically connected to the voltage regulator (2), a manual low-voltage box (4), and a control module (5) wirelessly connected to the test circuit module (1) and the manual low-voltage box (4), respectively. The test circuit module (1) includes a high-voltage cable aluminum conductor (11), terminal terminals (12) connected to the two ends of the high-voltage cable aluminum conductor (11) to form a closed loop, a number of aluminum connecting tubes (13) evenly distributed and pressed onto the high-voltage cable aluminum conductor (11), and a number of through-cores sleeved on the high-voltage cable aluminum conductor (11). The transformer (14), the current transformer (15) sleeved on the aluminum conductor (11) of the high-voltage cable, the data acquisition box (16), and several temperature acquisition wires (17) and current acquisition wires (18) are connected in parallel to each other and then connected to the voltage regulator (2) for electrical signal. The data acquisition box (16) is connected to the current transformer (15) for electrical signal through the current acquisition wires (18). The data acquisition box (16) is connected to the aluminum conductor (11) of the high-voltage cable, the aluminum connecting pipe (13) and the terminal terminal (12) for electrical signal through several temperature acquisition wires (17) respectively, for monitoring its temperature.

2. The automated control device for a high-voltage cable aluminum conductor circuit according to claim 1, characterized in that: The end of the temperature acquisition wire (17) is provided with a first probe (171) and a second probe (172), wherein the first probe (171) is used to contact the surface of the aluminum connecting tube (13) or the terminal terminal (12) to measure the temperature, and the second probe (172) is used to contact the surface of the aluminum conductor (11) of the high-voltage cable to measure the temperature.

3. The automated control device for a high-voltage cable aluminum conductor circuit according to claim 2, characterized in that: The data acquisition box (16) includes an outer shielded aluminum box (161), a shielding cover (169) that cooperates with the outer shielded aluminum box (161), a LoRa wireless communication module (162), a temperature acquisition module (163), a current acquisition module (164), and a current transmitter (165) disposed inside the outer shielded aluminum box (161), a filter and isolation transformer composite socket (166) disposed outside the outer shielded aluminum box (161), and several K-type connectors (167) and current sockets (168). The temperature acquisition module (163) is connected to the temperature acquisition wire through the K-type connectors (167). (17) Electrical signal connection: The current transmitter (165) is electrically connected to the current acquisition wire (18) through the current socket (168), the current acquisition module (164) is electrically connected to the current transmitter (165), the temperature acquisition module (163) and the current acquisition module (164) are both electrically connected to the LoRa wireless communication module (162), the filter and isolation transformer composite socket (166) is plugged into a filter and isolation transformer, and the shielding cover (169) is provided with an antenna (1691) that is electrically connected to the LoRa wireless communication module (162).

4. The automated control device for a high-voltage cable aluminum conductor circuit according to claim 1, characterized in that: The number of core transformers (14) is three, and they are connected in parallel.

5. The automated control device for a high-voltage cable aluminum conductor circuit according to claim 1, characterized in that: The control module (5) includes a computer system. The computer system communicates with the test line module (1) and the manual control low-voltage box (4) via LoRa wireless communication. It is used to collect temperature data and current data in real time and automatically adjust the output voltage and current of the voltage regulator (2) through preset parameters.

6. The automated control device for the aluminum conductor circuit of a high-voltage cable according to claim 1, characterized in that: The high-voltage control box (3) includes an overcurrent protector and an overvoltage protector for protecting the circuit.

7. The automated control device for a high-voltage cable aluminum conductor circuit according to claim 1, characterized in that: The manual control low-voltage box (4) includes a manual control module and an automatic control module. The manual control module is used to manually adjust the voltage regulator (2). The automatic control module is wirelessly connected to the control module (5) to realize dual control functions.

8. The automated control device for a high-voltage cable aluminum conductor circuit according to claim 1, characterized in that: The voltage regulator (2) has an output voltage range of 2V to 420V, which is used to simulate different operating conditions of the cable.

9. A test method for an automated control device for a high-voltage cable aluminum conductor circuit as described in claim 3, characterized in that, Includes the following steps: S1. Conduct the first thermal cycle test: Apply alternating current to the core transformer (14) through the voltage regulator (2) to heat the aluminum conductor (11) of the high-voltage cable, and monitor the temperature of the aluminum conductor (11) of the high-voltage cable through the second probe (172) of the temperature acquisition wire (17), and monitor the temperature of the aluminum connecting pipe (13) through the first probe (171). S2. When the temperature of the high-voltage cable aluminum conductor (11) reaches the first stable state as monitored by the second probe (172), the temperature of the high-voltage cable aluminum conductor (11) is recorded as θ. R The first stable state refers to the temperature change range of the aluminum conductor (11) of the high-voltage cable within ±2℃ within 15 minutes; S3. Under the first stable state, the intermediate temperature value of the aluminum connecting pipe (13) is obtained based on the monitoring data of the first probe (171); S4. If the median temperature of the aluminum connecting pipe (13) is greater than or equal to 100°C, record the current temperature of the high-voltage cable aluminum conductor (11) as θ. R The second thermal cycle test begins. If the intermediate temperature of the aluminum connecting tube (13) is less than 100°C, the voltage regulator (2) is controlled by the control module (5) to increase the loop current until the intermediate temperature of the aluminum connecting tube (13) reaches 100°C and the temperature of the high-voltage cable aluminum conductor (11) is less than or equal to 140°C, or only the temperature of the high-voltage cable aluminum conductor (11) reaches 140°C. The current temperature of the high-voltage cable aluminum conductor (11) is recorded as θ. R The second thermal cycling test was then initiated. S5. Conduct a second thermal cycle test: Apply alternating current through the voltage regulator (2) to heat the aluminum conductor (11) of the high-voltage cable to θ. R And record from the start of heating until the temperature reaches θ R The required heating time t1, and the required cooling time t2 to subsequently cool to below 35°C; S6. Conduct multiple thermal cycle tests: Using the heating time t1 and cooling time t2 as the period, conduct multiple thermal cycles; S7. During the thermal cycling test, temperature and current data are monitored in real time through the temperature acquisition wire (17) and the current acquisition wire (18), and the voltage regulator (2) is automatically adjusted by the control module (5) to maintain the temperature of the aluminum conductor (11) of the high-voltage cable at θ. R Within ±2℃ range; S8. All monitoring data are transmitted to the control module (5) via the LoRa wireless communication module (162), and a test report is generated based on the collected data.

10. A test method for an automated control device for a high-voltage cable aluminum conductor circuit according to claim 9, characterized in that: In step S6, the heating time t1 is greater than or equal to the minimum heating time specified based on the nominal cross-sectional area of ​​the conductor, wherein, When 16 mm² < nominal conductor cross-sectional area ≤ 50 mm², the shortest heating time is ≥ 5 min; When 50 mm² < nominal conductor cross-sectional area ≤ 150 mm², the shortest heating time is ≥ 10 min; When 150 mm² < nominal conductor cross-sectional area ≤ 630 mm², the shortest heating time is ≥ 15 min; When the nominal cross-sectional area of ​​the conductor is greater than 630 mm², the shortest heating time is ≥20 min.

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