Cable electric heating aging detection method and system based on bending laying

Abstract

The invention discloses a cable electric heating aging detection method and system based on bending laying. The method and system are suitable for an upper computer of the cable electric heating aging detection system based on bending laying. The system comprises an oil bath circulating device, a pressurization control device, a bending control device and a to-be-tested cable, the method comprises the steps of obtaining the length of a to-be-measured cable and coordinates of an oil bath circulating device; controlling the oil bath circulating device to heat the to-be-tested cable according to the preset temperature, so that the to-be-tested cable is kept in a constant-temperature state after reaching the preset temperature; controlling a pressurization control device to carry out pressurization operation on the to-be-tested cable according to the preset voltage value, so that the to-be-tested cable is kept in a constant-voltage state; calculating the coordinates of a target bending point according to the length of the cable to be measured and the coordinates of the oil bath circulating device; and according to the target bending point coordinate and the preset bending stress, controlling a bending control device to apply bending stress to the to-be-detected cable to obtain a detection result of the to-be-detected cable. According to the invention, the detection accuracy of the to-be-detected cable is improved.

Description

Technical Field

[0001] The present invention relates to the field of high voltage and insulation technology, and in particular to a method and system for detecting electric and thermal aging of cables based on bending laying. Background Art

[0002] In actual operation, cables, especially when laid in complex terrain or in a space-constrained environment, often need to withstand certain bending stresses. Long-term bending and laying will not only change the mechanical state of the cable, but may also accelerate the aging of key parts such as the insulation layer and cable sheath, thereby affecting the electrical performance and service life of the cable. In addition, the cable will inevitably be subjected to electrical and thermal stresses during operation, especially in high-load or high-temperature environments, where the increase in cable temperature will further aggravate the aging of the material.

[0003] At present, the evaluation methods for cable thermal aging are relatively mature, such as high-temperature aging chambers and thermal cycle test devices, which mainly focus on the thermal performance and thermal aging characteristics of cable materials. However, in the bending laying scenario, there is less coordinated evaluation between electrothermal aging and bending stress. Conventional thermal aging test devices cannot apply static bending stress, resulting in deviations in the evaluation of cable electrothermal aging under bending laying and low detection accuracy. Summary of the invention

[0004] The embodiments of the present invention provide a method and system for detecting electric and thermal aging of cables based on curved laying, which can effectively solve the problems in the prior art of less coordinated evaluation between electric and thermal aging and bending stress in curved laying scenarios, and inability to apply static bending stress using conventional thermal aging experimental equipment, resulting in deviations in the evaluation of electric and thermal aging of cables under curved laying and low detection accuracy.

[0005] An embodiment of the present invention provides a cable electrothermal aging detection method based on bending laying, which is applicable to a host computer of a cable electrothermal aging detection system based on bending laying; the cable electrothermal aging detection system based on bending laying comprises: an oil bath circulation device, a pressurization control device, a bending control device and a cable to be tested;

[0006] The cable to be tested is placed in the oil bath circulation device; the oil bath circulation device is connected to the pressurization control device; the bending control device is located above the oil bath circulation device

[0007] The cable electrothermal aging detection method based on bending laying comprises:

[0008] Obtain the length of the cable to be measured and the coordinates of the oil bath circulation device;

[0009] The oil bath circulation device is controlled to heat the cable to be tested according to the preset temperature, so that the cable to be tested maintains a constant temperature state after reaching the preset temperature;

[0010] Controlling the pressurization control device to pressurize the cable to be tested according to the preset voltage value, so that the cable to be tested maintains a constant voltage state after reaching the preset voltage value;

[0011] Calculating the coordinates of the target bending point according to the length of the cable to be measured and the coordinates of the oil bath circulation device;

[0012] According to the target bending point coordinates and the preset bending stress, the bending control device is controlled to apply the bending stress to the cable to be tested, so as to obtain the detection result of the cable to be tested.

[0013] Furthermore, the oil bath circulation device comprises: a heating resistance wire, an insulating support bracket and an oil bath heating container;

[0014] The heating resistor wire is used to convert electrical energy into thermal energy to heat the cable to be tested and keep the cable to be tested at a constant temperature after reaching a preset temperature.

[0015] The insulating support bracket is used to support the cable to be tested;

[0016] The oil bath heating container is used to accommodate the insulating support bracket and the cable to be tested.

[0017] Furthermore, the pressure control device includes: a high voltage power supply, a protection resistor and a high frequency current transformer;

[0018] The high-voltage power supply is connected to the protection resistor and the cable to be tested, and is used to provide voltage to perform a pressurization operation on the cable to be tested;

[0019] The protective resistor is connected to the cable to be tested, and is used to prevent the cable to be tested from being damaged by excessive voltage and to maintain a stable voltage output of the high-voltage power supply;

[0020] The high-frequency current transformer is coupled to the cable to be tested and is used to sense the partial discharge signal of the cable to be tested, so as to obtain the detection result of the cable to be tested according to the partial discharge signal.

[0021] Furthermore, the pressurization control device further includes: a partial discharge instrument and an oscilloscope;

[0022] The partial discharge instrument is connected to the oscilloscope, and is used to receive the partial discharge signal, filter the partial discharge signal, obtain a target signal, and transmit the target signal to the oscilloscope;

[0023] The oscilloscope is connected to the host computer, and is used for receiving the target signal and transmitting the target signal to the host computer; and displaying a graph corresponding to the target signal.

[0024] Further, the bending control device comprises: a drill platform and a drill bit;

[0025] The drill stand is connected to the drill platform and is used to fix the drill bit so that the drill bit remains stable;

[0026] The drill bit is used to apply a preset bending stress in a vertical direction to the cable to be tested at a target bending point corresponding to the coordinates of the target bending point.

[0027] Furthermore, the cable to be tested comprises: an inner conductor layer, an outer conductor layer, a main insulating layer, an outer semiconductor layer, a metal shielding layer and an outer sheath layer.

[0028] As an improvement of the above solution, another embodiment of the present invention provides a cable electrothermal aging detection system based on bending laying, comprising: a host computer, an oil bath circulation device, a pressurization control device, a bending control device and a cable to be tested;

[0029] The host computer is connected to the oil bath circulation device, the pressurization control device and the bending control device;

[0030] The host computer is used to control the oil bath circulation device to heat the cable to be tested according to a preset temperature; control the pressurization control device to pressurize the cable to be tested according to a preset voltage value; and obtain the length of the cable to be tested and the coordinates of the oil bath circulation device, calculate the target bending point coordinates according to the length of the cable to be tested and the coordinates of the oil bath circulation device, and control the bending control device to apply bending stress to the cable to be tested according to the target bending point coordinates and the preset bending stress, so as to obtain the detection result of the cable to be tested;

[0031] The oil bath circulation device is connected to the pressurization control device and is used to heat the cable to be tested so that the cable to be tested can maintain a constant temperature after reaching a preset temperature;

[0032] The pressure control device is connected to the cable to be tested and is used to perform a pressure operation on the cable to be tested so that the cable to be tested maintains a constant pressure state after reaching a preset voltage value;

[0033] The bending control device is located above the oil bath circulation device and is used to apply bending stress to the cable to be tested.

[0034] Furthermore, the oil bath circulation device comprises: a heating resistance wire, an insulating support bracket and an oil bath heating container;

[0035] The heating resistor wire is used to convert electrical energy into thermal energy to heat the cable to be tested and keep the cable to be tested at a constant temperature after reaching a preset temperature.

[0036] The insulating support bracket is used to support the cable to be tested;

[0037] The oil bath heating container is used to accommodate the insulating support bracket and the cable to be tested.

[0038] Furthermore, the pressure control device includes: a high voltage power supply, a protection resistor and a high frequency current transformer;

[0039] The high-voltage power supply is connected to the protection resistor and the cable to be tested, and is used to provide voltage to perform a pressurization operation on the cable to be tested;

[0040] The protective resistor is connected to the cable to be tested, and is used to prevent the cable to be tested from being damaged by excessive voltage and to maintain a stable voltage output of the high-voltage power supply;

[0041] The high-frequency current transformer is coupled to the cable to be tested and is used to sense the partial discharge signal of the cable to be tested, so as to obtain the detection result of the cable to be tested according to the partial discharge signal.

[0042] Further, the bending control device comprises: a drill platform and a drill bit;

[0043] The drill stand is connected to the drill platform and is used to fix the drill bit so that the drill bit remains stable;

[0044] The drill bit is used to apply a preset bending stress in a vertical direction to the cable to be tested at a target bending point corresponding to the coordinates of the target bending point.

[0045] By implementing the present invention, at least the following beneficial effects are achieved:

[0046] The present invention provides a cable electrothermal aging detection method and system based on bending laying, and the method is applicable to the host computer of the cable electrothermal aging detection system based on bending laying; the cable electrothermal aging detection system based on bending laying comprises: an oil bath circulation device, a pressurization control device, a bending control device and a cable to be tested; the cable to be tested is placed in the oil bath circulation device; the oil bath circulation device is connected to the pressurization control device; the bending control device is located above the oil bath circulation device; the cable electrothermal aging detection method based on bending laying comprises: obtaining the length of the cable to be tested and the oil bath circulation device; The coordinates of the oil bath circulation device; the oil bath circulation device is controlled to heat the cable to be tested according to the preset temperature, so that the cable to be tested maintains a constant temperature after reaching the preset temperature; the pressure control device is controlled to pressurize the cable to be tested according to the preset voltage value, so that the cable to be tested maintains a constant voltage after reaching the preset voltage value; the target bending point coordinates are calculated according to the length of the cable to be tested and the coordinates of the oil bath circulation device; according to the target bending point coordinates and the preset bending stress, the bending control device is controlled to apply bending stress to the cable to be tested, and the test result of the cable to be tested is obtained. Temperature control is achieved through the oil bath circulation device, voltage control is achieved through the pressure control device, and bending control is achieved through the bending control device. The combined effects of electrothermal aging and bending stress are integrated to achieve coordinated detection of the cable to be tested, which can comprehensively evaluate the performance of the cable under electrothermal aging and bending stress, and improve the accuracy of the detection of the cable to be tested. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 It is a flow chart of a method for detecting electric and thermal aging of cables based on bending laying provided by one embodiment of the present invention;

[0048] Figure 2 It is a structural connection diagram of a cable electrothermal aging detection system based on curved laying provided by one embodiment of the present invention;

[0049] Figure 3 is a schematic diagram of electrical connection and mechanical support provided by an embodiment of the present invention;

[0050] Figure 4 is a schematic structural diagram of a bending control device provided by an embodiment of the present invention;

[0051] Figure 5 It is a side view of a bending control device provided by one embodiment of the present invention. DETAILED DESCRIPTION

[0052] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0053] See also Figure 1 , is a flow chart of a cable electrothermal aging detection method based on bending laying provided by an embodiment of the present invention, the method is applicable to a host computer of a cable electrothermal aging detection system based on bending laying; the cable electrothermal aging detection system based on bending laying comprises: an oil bath circulation device, a pressurization control device, a bending control device and a cable to be tested;

[0054] The cable to be tested is placed in the oil bath circulation device; the oil bath circulation device is connected to the pressurization control device; the bending control device is located above the oil bath circulation device; Figure 2 As shown in the figure, the cable and its bending device are the locations of the cable to be tested and the bending control device. The oil bath circulation device is connected to the pressurization control device and the bending control device. Figure 2 The computer in the figure is the host computer.

[0055] The cable electrothermal aging detection method based on bending laying comprises:

[0056] S1, obtaining the length of the cable to be measured and the coordinates of the oil bath circulation device;

[0057] Specifically, the cable to be tested is placed in the oil bath circulation device, and the cable to be tested includes: an inner conductor layer, an outer conductor layer, a main insulation layer, an outer semiconductor layer, a metal shielding layer and an outer sheath layer.

[0058] S2, controlling the oil bath circulation device to heat the cable to be tested according to a preset temperature, so that the cable to be tested maintains a constant temperature state after reaching the preset temperature;

[0059] Preferably, the oil bath circulation device comprises: a heating resistance wire, an insulating support bracket and an oil bath heating container;

[0060] The heating resistor wire is used to convert electrical energy into thermal energy to heat the cable to be tested and keep the cable to be tested at a constant temperature after reaching a preset temperature.

[0061] The insulating support bracket is used to support the cable to be tested;

[0062] The oil bath heating container is used to accommodate the insulating support bracket and the cable to be tested.

[0063] Specifically, the cable to be tested is placed on an insulating support bracket of an oil bath circulation device, such as Figure 3 As shown, Figure 3 The shaded part in the middle is the oil medium contained in the oil bath heating container. The cable to be tested is immersed in the oil bath, and the oil medium is heated by the heating resistor wire to heat the cable to be tested to the preset temperature. When the cable to be tested reaches the preset temperature, the upper computer stops heating by controlling the heating resistor wire of the oil bath circulation device, and keeps the cable to be tested at a constant temperature. The working principle of the heating resistor wire is based on the thermal effect of electric current, that is, when the current passes through the resistor wire, the collision between the electron and the atomic nucleus will generate heat, thereby increasing the temperature of the resistor wire and its surrounding environment, thereby heating the oil medium and heating the cable to be tested to the preset temperature. The heating resistor wire is usually installed at the bottom or side of the oil bath heating container to ensure that the oil medium can be heated evenly. The oil bath heating container is used to accommodate the insulating support bracket and the cable to be tested, and is usually made of stainless steel, glass or other high temperature resistant and corrosion resistant materials to ensure that it will not be damaged by high temperature or medium corrosion during the heating process. The shape and size of the oil bath heating container are usually designed according to the actual application requirements of the cable to be tested. For example, in some cases, a larger container may be required to accommodate more oil medium and the cable to be tested; in other cases, a smaller container may be required to improve heating efficiency and temperature uniformity. The oil bath heating container also includes an oil inlet and an oil outlet. The oil inlet is the inlet for introducing new hot oil or circulating oil in the oil bath heating container, and the oil outlet is the outlet for discharging hot oil or circulating oil in the oil bath heating container. The oil level is controlled by controlling the flow of oil in and out so that the oil medium completely covers the cable to be tested.

[0064] S3, controlling the pressurization control device to pressurize the cable to be tested according to the preset voltage value, so that the cable to be tested maintains a constant voltage state after reaching the preset voltage value;

[0065] Specifically, the pressure control device includes: a high-voltage power supply, a protection resistor and a high-frequency current transformer;

[0066] The high-voltage power supply is connected to the protection resistor and the cable to be tested, and is used to provide voltage to perform a pressurization operation on the cable to be tested;

[0067] The protective resistor is connected to the cable to be tested, and is used to prevent the cable to be tested from being damaged by excessive voltage and to maintain a stable voltage output of the high-voltage power supply;

[0068] The high-frequency current transformer is coupled to the cable to be tested and is used to sense the partial discharge signal of the cable to be tested, so as to obtain the detection result of the cable to be tested according to the partial discharge signal.

[0069] Preferably, the preset voltage value is set according to the detection requirements of the cable to be tested, such as a voltage increase rate of 500V / s. Figure 2As shown, the cable to be tested, the high voltage power supply, the protection resistor and the cable to be tested ( Figure 2 The HFCT in the cable transformer forms a high-voltage circuit. The high-voltage power supply is connected to the protection resistor and the high-frequency current transformer, and is used to provide voltage to pressurize the cable to be tested, simulating the voltage level that the cable to be tested may encounter in actual operation. The output high voltage is applied to the cable to be tested after passing through the protection resistor. The protection resistor is connected to the cable to be tested, and the resistance value exceeds five kiloohms. It is used to prevent the voltage from being too large and damaging the cable to be tested, and to maintain the stable voltage output of the high-voltage power supply. It is connected in series between the high-voltage power supply and the cable to be tested, and the protection resistor is connected to the high-voltage power supply and the cable to be tested. The high-frequency current transformer (HFCT) is coupled to the cable to be tested, and is used to sense the partial discharge signal of the cable to be tested, so that the detection result of the cable to be tested can be obtained according to the partial discharge signal.

[0070] Preferably, the pressurization control device further comprises: a partial discharge meter and an oscilloscope;

[0071] The partial discharge instrument is connected to the oscilloscope, and is used to receive the partial discharge signal, filter the partial discharge signal, obtain a target signal, and transmit the target signal to the oscilloscope;

[0072] The oscilloscope is connected to the host computer, and is used for receiving the target signal and transmitting the target signal to the host computer; and displaying a graph corresponding to the target signal.

[0073] In a preferred embodiment of the present invention, a partial discharge instrument and an oscilloscope are usually used in combination. The partial discharge instrument can amplify and filter the partial discharge signal to obtain a target signal; and the oscilloscope transmits the processed partial discharge signal (target signal) to a host computer for storage, and the host computer can further analyze and process the data. At the same time, the oscilloscope can also display a graph corresponding to the target signal.

[0074] S4, calculating the coordinates of the target bending point according to the length of the cable to be measured and the coordinates of the oil bath circulation device;

[0075] In a preferred embodiment of the present invention, the target bending point coordinates are the coordinates of the midpoint of the cable to be tested. The total length of the cable to be tested is measured and recorded as L. The oil bath circulation device usually has a fixed installation position, and its coordinates can be determined relative to a reference point or reference coordinate system. In order to simplify the calculation, the center point of the oil bath circulation device can be assumed to be the coordinate origin (0,0), or a suitable reference point can be selected as the coordinate origin according to actual needs. If the cable is placed in a straight line and the center point of the oil bath circulation device is aligned with one end or the center of the cable, then the midpoint coordinate will directly correspond to the position of half the cable length on the coordinate axis. Assuming that the cable is placed along the x-axis and the center point of the oil bath circulation device is aligned with one end of the cable (for example, one end of the cable is at the coordinate origin), the midpoint coordinate will be (L / 2,0) (if the cable is not offset in the y-axis direction). If the cable is offset in the y-axis direction, the midpoint coordinate will be (L / 2,y_offset), where y_offset is the offset of the cable in the y-axis direction. In practical applications, if the cable is not placed in a straight line, or the center point of the oil bath circulation device is not aligned with one end or the center of the cable, then a more complex geometric method may be required to calculate the coordinates of the target bending point.

[0076] S5. According to the target bending point coordinates and the preset bending stress, the bending control device is controlled to apply bending stress to the cable to be tested, so as to obtain a test result of the cable to be tested.

[0077] Specifically, the bending control device includes: a drill platform and a drill bit;

[0078] The drill stand is connected to the drill platform and is used to fix the drill bit so that the drill bit remains stable;

[0079] The drill bit is used to apply a preset bending stress in a vertical direction to the cable to be tested at a target bending point corresponding to the coordinates of the target bending point.

[0080] In a preferred embodiment of the present invention, the size of the drill platform is adapted to the oil bath heating container where the cable to be tested is located, and is used to fix the drill bit and ensure that it maintains a stable position during the test process; the contact area between the drill bit and the surface of the cable to be tested is large, so that the mechanical bending stress can be evenly applied. Figure 3 As shown in FIG. 1 , the drill bit 2 of the bending control device is located directly above the middle section of the cable to be tested. Figure 4 As shown, the side view of the bending control device is as shown Figure 5The positions of the drill platform 1 and the drill bit 2 are adjusted by the host computer so that the drill bit is located above the target bending point corresponding to the coordinates of the target bending point, and then the drill bit is controlled to fall to apply a preset bending stress in the vertical direction to the cable to be tested 3 on the insulating support bracket 4. In this process, the displacement of the drill bit falling is kept below the bending radius corresponding to the preset bending stress.

[0081] In a preferred embodiment of the present invention, when heating operation, pressurization operation and bending stress are applied simultaneously, the test results of the cable to be tested generally include the following types of data. Partial discharge signal data: The partial discharge activity inside the cable to be tested is monitored in real time by the partial discharge instrument, and the amplitude, frequency, waveform and duration of the discharge are recorded, which is helpful to analyze the changes in the electrical properties of the cable to be tested under heating, pressurization and bending stress; voltage data: record the applied voltage (including instantaneous voltage and stable voltage) and its rate of change to ensure that the cable is tested under the preset voltage; temperature data: record the temperature change of the cable to be tested by the temperature sensor, monitor the temperature change of the cable to be tested during the heating process, and ensure that the temperature is stable within the preset temperature; bending radius data: record the bending radius of the stress-bearing part of the cable to be tested to ensure that the bending stress of the cable is consistent with the preset bending stress; partial discharge related spectrum: use an oscilloscope or a host computer to generate a spectrum of partial discharge signals to show the change trend of partial discharge under different voltages. All these test results will be recorded in digital form and stored for subsequent analysis and evaluation.

[0082] In the detection process, when the temperature and applied voltage of the cable under test are not adjusted, the partial discharge amplitude reaches the set upper limit, and the frequency of partial discharge increases significantly with the increase of applied voltage. In this case, it can be considered that the insulation performance of the cable under test has been significantly degraded, and the risk of failure has increased. At this time, the degree of cable aging can be judged based on the trend of discharge amplitude and frequency changes, and the influence of electrical, thermal, and bending stresses on cable aging can be evaluated through comparative experiments.

[0083] This embodiment solves the problem that in the bending laying scenario, electrothermal aging and bending stress are difficult to be applied simultaneously, making it impossible to conduct three-stress coordinated aging research. The cable bending laying device of this embodiment provides an effective platform for studying the performance of cables under high temperature, high voltage and mechanical stress, and has strong practical application value, especially in the field of cable material and structure optimization. Through this embodiment, the aging process of the cable and its failure mode can be explored in more depth, thereby providing a scientific basis for the design and reliability improvement of the cable, and even providing practical support for further cable breakdown.

[0084] By implementing this embodiment, the length of the cable to be tested and the coordinates of the oil bath circulation device are obtained; the oil bath circulation device is controlled to heat the cable to be tested according to a preset temperature, so that the cable to be tested maintains a constant temperature state after reaching the preset temperature; the pressure control device is controlled to pressurize the cable to be tested according to a preset voltage value, so that the cable to be tested maintains a constant voltage state after reaching the preset voltage value; the target bending point coordinates are calculated according to the length of the cable to be tested and the coordinates of the oil bath circulation device; according to the target bending point coordinates and the preset bending stress, the bending control device is controlled to apply bending stress to the cable to be tested, and the test result of the cable to be tested is obtained. Temperature control is achieved through the oil bath circulation device, voltage control is achieved through the pressure control device, and bending control is achieved through the bending control device. The combined effects of electrothermal aging and bending stress are integrated to achieve coordinated detection of the cable to be tested, which can comprehensively evaluate the performance of the cable under electrothermal aging and bending stress, and improve the accuracy of the detection of the cable to be tested.

[0085] See also Figure 2 , is a connection diagram of a cable electrothermal aging detection system based on bending laying provided by an embodiment of the present invention, comprising: a host computer, an oil bath circulation device, a pressurization control device, a bending control device and a cable to be tested;

[0086] The host computer is connected to the oil bath circulation device, the pressurization control device and the bending control device;

[0087] The host computer is used to control the oil bath circulation device to heat the cable to be tested according to a preset temperature; control the pressurization control device to pressurize the cable to be tested according to a preset voltage value; and obtain the length of the cable to be tested and the coordinates of the oil bath circulation device, calculate the target bending point coordinates according to the length of the cable to be tested and the coordinates of the oil bath circulation device, and control the bending control device to apply bending stress to the cable to be tested according to the target bending point coordinates and the preset bending stress, so as to obtain the detection result of the cable to be tested;

[0088] The oil bath circulation device is connected to the pressurization control device and is used to heat the cable to be tested so that the cable to be tested can maintain a constant temperature after reaching a preset temperature;

[0089] The pressure control device is connected to the cable to be tested and is used to perform a pressure operation on the cable to be tested so that the cable to be tested maintains a constant pressure state after reaching a preset voltage value;

[0090] The bending control device is located above the oil bath circulation device and is used to apply bending stress to the cable to be tested.

[0091] In a preferred embodiment of the present invention, the host computer is Figure 2The computer, the cable to be tested and the bending control device are Figure 2 The cable and its bending device are located in the position, connected with the pressurization control device and the oil bath circulation device, to complete the detection task of the cable to be tested.

[0092] Specifically, the oil bath circulation device comprises: a heating resistance wire, an insulating support bracket and an oil bath heating container;

[0093] The heating resistor wire is used to convert electrical energy into thermal energy to heat the cable to be tested and keep the cable to be tested at a constant temperature after reaching a preset temperature.

[0094] The insulating support bracket is used to support the cable to be tested;

[0095] The oil bath heating container is used to accommodate the insulating support bracket and the cable to be tested.

[0096] Preferably, the pressure control device comprises: a high voltage power supply, a protection resistor and a high frequency current transformer;

[0097] The high-voltage power supply is connected to the protection resistor and the cable to be tested, and is used to provide voltage to perform a pressurization operation on the cable to be tested;

[0098] The protective resistor is connected to the cable to be tested, and is used to prevent the cable to be tested from being damaged by excessive voltage and to maintain a stable voltage output of the high-voltage power supply;

[0099] The high-frequency current transformer is coupled to the cable to be tested and is used to sense the partial discharge signal of the cable to be tested, so as to obtain the detection result of the cable to be tested according to the partial discharge signal.

[0100] In another preferred embodiment of the present invention, the pressurization control device further comprises: a partial discharge instrument and an oscilloscope;

[0101] The partial discharge instrument is connected to the oscilloscope, and is used to receive the partial discharge signal, filter the partial discharge signal, obtain a target signal, and transmit the target signal to the oscilloscope;

[0102] The oscilloscope is connected to the host computer, and is used for receiving the target signal and transmitting the target signal to the host computer; and displaying a graph corresponding to the target signal.

[0103] Preferably, the bending control device comprises: a drill platform and a drill bit;

[0104] The drill stand is connected to the drill platform and is used to fix the drill bit so that the drill bit remains stable;

[0105] The drill bit is used to apply a preset bending stress in a vertical direction to the cable to be tested at a target bending point corresponding to the coordinates of the target bending point.

[0106] The present invention provides a cable electrothermal aging detection system based on bending laying, comprising a host computer, an oil bath circulation device, a pressurization control device, a bending control device and a cable to be tested; the host computer is connected to the oil bath circulation device, the pressurization control device and the bending control device; the host computer is used to control the oil bath circulation device to heat the cable to be tested according to a preset temperature; control the pressurization control device to pressurize the cable to be tested according to a preset voltage value; and obtain the length of the cable to be tested and the coordinates of the oil bath circulation device, and calculate the target cable according to the length of the cable to be tested and the coordinates of the oil bath circulation device. The coordinates of the target bending point are marked, and according to the target bending point coordinates and the preset bending stress, the bending control device is controlled to apply bending stress to the cable to be tested, so as to obtain the detection result of the cable to be tested; the oil bath circulation device is connected to the pressurization control device, and is used to heat the cable to be tested, so that the cable to be tested can maintain a constant temperature after reaching the preset temperature; the pressurization control device is connected to the cable to be tested, and is used to pressurize the cable to be tested, so that the cable to be tested can maintain a constant voltage after reaching the preset voltage value; the bending control device is located above the oil bath circulation device, and is used to apply bending stress to the cable to be tested. Temperature control is achieved through the oil bath circulation device, voltage control is achieved through the pressurization control device, and bending control is achieved through the bending control device. The combined effects of electrothermal aging and bending stress are integrated to achieve coordinated detection of the cable to be tested, which can comprehensively evaluate the performance of the cable under electrothermal aging and bending stress, and improve the accuracy of the detection of the cable to be tested.

[0107] It should be noted that the system embodiments described above are merely schematic, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. In addition, in the drawings of the system embodiments provided by the present invention, the connection relationship between the devices indicates that there is a communication connection or an electrical connection or a signal coupling relationship between them, which may be specifically implemented as one or more communication buses or signal lines. A person of ordinary skill in the art may understand and implement it without paying any creative effort.

[0108] Those skilled in the art can clearly understand that, for the sake of convenience and brevity, the specific working process of the system described above can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here.

[0109] The above is a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A method for detecting the electrothermal aging of cables based on bending laying, characterized in that: A host computer suitable for a cable electrothermal aging detection system based on bending laying; the cable electrothermal aging detection system based on bending laying comprises: an oil bath circulation device, a pressurization control device, a bending control device and a cable to be tested; The cable to be tested is placed in the oil bath circulation device; the oil bath circulation device is connected to the pressurization control device; the bending control device is located above the oil bath circulation device; The cable electrothermal aging detection method based on bending laying comprises: Obtain the length of the cable to be measured and the coordinates of the oil bath circulation device; The oil bath circulation device is controlled to heat the cable to be tested according to the preset temperature, so that the cable to be tested maintains a constant temperature state after reaching the preset temperature; Controlling the pressurization control device to pressurize the cable to be tested according to the preset voltage value, so that the cable to be tested maintains a constant voltage state after reaching the preset voltage value; Calculating the coordinates of the target bending point according to the length of the cable to be measured and the coordinates of the oil bath circulation device; According to the target bending point coordinates and the preset bending stress, the bending control device is controlled to apply the bending stress to the cable to be tested, so as to obtain the detection result of the cable to be tested.

2. A method for detecting the electrothermal aging of cables based on bending laying as claimed in claim 1, characterized in that: The oil bath circulation device comprises: a heating resistance wire, an insulating support bracket and an oil bath heating container; The heating resistor wire is used to convert electrical energy into thermal energy to heat the cable to be tested and keep the cable to be tested at a constant temperature after reaching a preset temperature. The insulating support bracket is used to support the cable to be tested; The oil bath heating container is used to accommodate the insulating support bracket and the cable to be tested.

3. A cable electrothermal aging detection method based on bending laying as claimed in claim 1, characterized in that: The pressure control device includes: a high voltage power supply, a protection resistor and a high frequency current transformer; The high-voltage power supply is connected to the protection resistor and the cable to be tested, and is used to provide voltage to perform a pressurization operation on the cable to be tested; The protective resistor is connected to the cable to be tested, and is used to prevent the cable to be tested from being damaged by excessive voltage and to maintain a stable voltage output of the high-voltage power supply; The high-frequency current transformer is coupled to the cable to be tested and is used to sense the partial discharge signal of the cable to be tested, so as to obtain the detection result of the cable to be tested according to the partial discharge signal.

4. A method for detecting the electrothermal aging of cables based on bending laying as claimed in claim 3, characterized in that: The pressurization control device further includes: a partial discharge instrument and an oscilloscope; The partial discharge instrument is connected to the oscilloscope, and is used to receive the partial discharge signal, filter the partial discharge signal, obtain a target signal, and transmit the target signal to the oscilloscope; The oscilloscope is connected to the host computer, and is used for receiving the target signal and transmitting the target signal to the host computer; and displaying a graph corresponding to the target signal.

5. The method for detecting the electrothermal aging of cables based on bending laying as claimed in claim 1, characterized in that: The bending control device comprises: a drill platform and a drill bit; The drill stand is connected to the drill platform and is used to fix the drill bit so that the drill bit remains stable; The drill bit is used to apply a preset bending stress in a vertical direction to the cable to be tested at a target bending point corresponding to the coordinates of the target bending point.

6. A method for detecting the electrothermal aging of cables based on bending laying as claimed in claim 1, characterized in that: The cable to be tested comprises: an inner conductor layer, an outer conductor layer, a main insulating layer, an outer semiconductor layer, a metal shielding layer and an outer sheath layer.

7. A cable electrothermal aging detection system based on curved laying, characterized in that: include: Host computer, oil bath circulation device, pressurization control device, bending control device and cable to be tested; The host computer is connected to the oil bath circulation device, the pressurization control device and the bending control device; The host computer is used to control the oil bath circulation device to perform heating operation on the cable to be tested according to a preset temperature; Controlling the pressurization control device to perform pressurization operation on the cable to be tested according to a preset voltage value; and obtaining the length of the cable to be tested and the coordinates of the oil bath circulation device, calculating the coordinates of the target bending point according to the length of the cable to be tested and the coordinates of the oil bath circulation device, and controlling the bending control device to apply bending stress to the cable to be tested according to the target bending point coordinates and the preset bending stress, so as to obtain the detection result of the cable to be tested; The oil bath circulation device is connected to the pressurization control device and is used to heat the cable to be tested so that the cable to be tested can maintain a constant temperature after reaching a preset temperature; The pressure control device is connected to the cable to be tested and is used to perform a pressure operation on the cable to be tested so that the cable to be tested maintains a constant pressure state after reaching a preset voltage value; The bending control device is located above the oil bath circulation device and is used to apply bending stress to the cable to be tested.

8. A cable electrothermal aging detection system based on curved laying as claimed in claim 7, characterized in that: The oil bath circulation device comprises: a heating resistance wire, an insulating support bracket and an oil bath heating container; The heating resistor wire is used to convert electrical energy into thermal energy to heat the cable to be tested and keep the cable to be tested at a constant temperature after reaching a preset temperature. The insulating support bracket is used to support the cable to be tested; The oil bath heating container is used to accommodate the insulating support bracket and the cable to be tested.

9. The cable electrothermal aging detection system based on curved laying as claimed in claim 7, characterized in that: The pressure control device includes: a high voltage power supply, a protection resistor and a high frequency current transformer; The high-voltage power supply is connected to the protection resistor and the cable to be tested, and is used to provide voltage to perform a pressurization operation on the cable to be tested; The protective resistor is connected to the cable to be tested, and is used to prevent the cable to be tested from being damaged by excessive voltage and to maintain a stable voltage output of the high-voltage power supply; The high-frequency current transformer is coupled to the cable to be tested and is used to sense the partial discharge signal of the cable to be tested, so as to obtain the detection result of the cable to be tested according to the partial discharge signal.

10. The cable electrothermal aging detection system based on bending laying as claimed in claim 7, characterized in that: The bending control device comprises: a drill platform and a drill bit; The drill stand is connected to the drill platform and is used to fix the drill bit so that the drill bit remains stable; The drill bit is used to apply a preset bending stress in a vertical direction to the cable to be tested at a target bending point corresponding to the coordinates of the target bending point.

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