An inspection device and method for insulation defects of a submarine cable molded joint

Abstract

The present application discloses a detection device and method for insulation defects of a submarine cable molded joint, which relates to the field of insulation detection of electrical equipment. The device includes a power supply component, a first switch component, a second switch component, an electrode measurement component, a collection component, and a control component. The control component is configured to: send a first status instruction to the first switch component to change the opening and closing status; send a second status instruction to the second switch component to change the opening and closing status; send a voltage status instruction to the power supply component to change the voltage status data provided to the conductor part for realizing detection; send a collection status instruction to the collection component to change the opening and closing status; receive and store the insulation defect detection data fed back by the collection component, and evaluate the insulation performance of the submarine cable molded joint according to the insulation defect detection data corresponding to different regions. The present application realizes non-destructive and timely detection of insulation defects of the submarine cable molded joint.

Description

Technical Field

[0001] This application relates to the field of electrical equipment insulation detection, and particularly to a detection device and method for insulation defects of submarine cable molded joints. Background Art

[0002] High-voltage submarine cables are crucial for long-distance cross-sea power transmission. Currently, the manufacturing length of a single submarine cable is limited. As a core component for flexible connection of long submarine cable lines, with the rapid development of offshore wind power in deep sea areas, higher requirements are put forward for the insulation reliability of molded joints. The insulation of molded joints mainly consists of two parts: body insulation and restoration insulation. Although the same insulation medium is used for restoration insulation as for body insulation, due to manufacturing process problems, interface defects are still inevitable between body insulation and restoration insulation, which leads to a serious decline in the insulation performance of molded joints and requires detection of the defects. Existing cable joint defect detections mainly include X-ray imaging, withstand voltage tests, partial discharge tests, etc., but they all inevitably damage the material structure or insulation performance. Summary of the Invention

[0003] The purpose of this application is to provide a detection device and method for insulation defects of submarine cable molded joints, so as to achieve non-destructive and timely detection of insulation defects of submarine cable molded joints.

[0004] To achieve the above purpose, this application provides the following solutions:

[0005] In a first aspect, this application provides a detection device for insulation defects of a submarine cable molded joint, which is connected to the submarine cable molded joint. The submarine cable molded joint includes a conductor part and an insulation part. The detection device for insulation defects of the submarine cable molded joint includes a power supply component, a first switch component, a second switch component, an electrode measurement component, a collection component, and a control component; the insulation part includes a body insulation area, a restoration insulation area, and a stress cone area;

[0006] The power supply component is connected to the conductor part through the first switch component; the collection component is connected to the electrode measurement component through the second switch component, and the electrode measurement component is arranged in any one of the body insulation area, the restoration insulation area, and the stress cone area; the control component is respectively connected to the power supply component, the first switch component, the second switch component, and the collection component;

[0007] The control component is configured to: send a first status instruction to the first switch component to change the on / off state of the first switch component; send a second status instruction to the second switch component to change the on / off state of the second switch component; send a voltage status instruction to the power supply component to change the voltage status data provided by the power supply component for the conductor part to implement detection; send a collection status instruction to the collection component to change the on / off state of the collection component; receive and store the insulation defect detection data fed back by the collection component, and evaluate the insulation performance of the submarine cable molded joint according to the insulation defect detection data corresponding to different regions; the insulation defect detection data is obtained via the electrode measurement component and the second switch component when the on / off state of the collection component is on.

[0008] In a second aspect, the present application provides a method for detecting insulation defects of a submarine cable molded joint, including:

[0009] Construct a detection device for insulation defects of a submarine cable molded joint;

[0010] Set the electrode measurement component in the body insulation area of the insulation part, and start detection based on the control component to obtain the first insulation defect detection data corresponding to the body insulation area;

[0011] Set the electrode measurement component in the restored insulation area of the insulation part, and start detection based on the control component to obtain the second insulation defect detection data corresponding to the restored insulation area;

[0012] Set the electrode measurement component in the stress cone area of the insulation part, and start detection based on the control component to obtain the third insulation defect detection data corresponding to the stress cone area;

[0013] In the control component, based on the first insulation defect detection data, the second insulation defect detection data, and the third insulation defect detection data, evaluate the insulation performance of the submarine cable molded joint and obtain an evaluation result.

[0014] According to the specific embodiments provided by this application, the following technical effects are achieved: This application provides a detection device and method for insulation defects of submarine cable molded joints. The device structure is as follows: The power supply component is connected to the conductor part through the first switch component, the acquisition component is connected to the electrode measurement component through the second switch component, and the electrode measurement component is arranged in any one of the body insulation area, the restored insulation area, and the stress cone area. The above structure is controlled for opening and closing, state adjustment, and receives and stores the insulation defect detection data fed back by the acquisition component, and evaluates the insulation performance of the submarine cable molded joint according to the insulation defect detection data corresponding to different areas. The device of this application realizes the detection of insulation defects of submarine cable molded joints through the electric control of each component, will not damage the material structure or insulation performance, and realizes non-destructive detection. Moreover, based on the voltage provided by the power supply component as the detection basis in this application, the timeliness of subsequent detection can be ensured, and the corresponding insulation defect detection data can be directly obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings in the following description are only some embodiments of this application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0016] Figure 1 It is a schematic structural diagram of a submarine cable molded joint in an embodiment of this application;

[0017] Figure 2 It is a schematic diagram of the setting area of the measurement electrode in an embodiment of this application;

[0018] Figure 3 It is a schematic diagram of a detection device for insulation defects of a submarine cable molded joint provided in an embodiment of this application;

[0019] Figure 4 It is a schematic flowchart of a detection method for insulation defects of a submarine cable molded joint provided in an embodiment of this application;

[0020] Figure 5 It is a schematic diagram for calculating the amount of internal space charge accumulation in insulation in an embodiment of this application;

[0021] Figure 6 It is a schematic diagram of the insulation size and measurement position of a submarine cable molded joint in an embodiment of this application.

[0022] Reference numerals: 1 - outer sheath, 2 - metal shield, 3 - insulation interface, 4 - restored insulation area, 5 - conductor shield area, 6 - body insulation area, 7 - insulation shield area, 8 - conductor part, 9 - stress cone area, 10 - first outer interface, 11 - first inner interface, 12 - second inner interface, 13 - second outer interface, 14 - measuring electrode, 15 - first switch component, 16 - second switch component, 17 - other measuring positions of the measuring electrode. Detailed implementation manners

[0023] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application.

[0024] For the molded joint of submarine cable, the present application provides a non-destructive detection method for insulation defects, which is carried out after the insulation part is prepared, so as to provide guarantee for the design, preparation and safe operation of the submarine cable molded joint, and eliminate the influence of insulation defects fundamentally and in time.

[0025] In order to make the above objects, features and advantages of the present application more obvious and understandable, the present application will be further described in detail below with reference to the accompanying drawings and specific implementation manners.

[0026] In an exemplary embodiment, the present application provides a detection device for insulation defects of a submarine cable molded joint. The detection device for insulation defects of the submarine cable molded joint includes a power supply assembly, a first switch component, a second switch component, an electrode measurement assembly, a collection assembly and a control assembly. The detection device for insulation defects of the submarine cable molded joint is connected to the submarine cable molded joint to realize corresponding insulation defect detection. The submarine cable molded joint includes a conductor part 8 and an insulation part, specifically as Figure 1 and Figure 2 shown, the submarine cable molded joint includes an outer sheath 1, a metal shield 2, an insulation interface 3, a restored insulation area 4, a conductor shield area 5, a body insulation area 6, an insulation shield area 7, a conductor part 8 and a stress cone area 9. The first outer interface 10, the first inner interface 11, the second inner interface 12 and the second outer interface 13 can also be divided on both sides of the restored insulation area.

[0027] Based on the above structure, the present application gives as Figure 3The schematic diagram shown, wherein the power supply component is connected to the conductor part through the first switch component 15; the acquisition component is connected to the electrode measurement component through the second switch component 16, and the electrode measurement component is arranged in any one of the body insulation area, the restored insulation area and the stress cone area; the control component is respectively connected to the power supply component, the first switch component, the second switch component and the acquisition component.

[0028] The control component is configured to: send a first status instruction to the first switch component 15 to change the opening and closing state of the first switch component 15; send a second status instruction to the second switch component 16 to change the opening and closing state of the second switch component 16; send a voltage status instruction to the power supply component to change the voltage status data provided by the power supply component to the conductor part for realizing detection; send an acquisition status instruction to the acquisition component to change the opening and closing state of the acquisition component; receive and store the insulation defect detection data fed back by the acquisition component, and evaluate the insulation performance of the submarine cable molded joint according to the insulation defect detection data corresponding to different areas; the insulation defect detection data is obtained through the electrode measurement component and the second switch component when the opening and closing state of the acquisition component is open.

[0029] In another application example, the power supply component includes a high-voltage DC power supply and a current-limiting resistor; the high-voltage DC power supply, the current-limiting resistor, the first switch component 15 and the conductor part are connected in series in sequence; the high-voltage DC power supply is used to provide a voltage within a preset voltage range for the conductor part, that is, the voltage provided by the high-voltage DC power supply is adjustable, and the preset voltage range can be 0 kV to 300 kV.

[0030] In another application example, the electrode measurement component includes a plurality of measurement electrodes 14 and an electrode fixing fixture corresponding to each measurement electrode; the electrode fixing fixture is used to fix the measurement electrode 14 on the insulation part, that is, the measurement electrode 14 is in direct insulation contact with the submarine cable molded joint; all the measurement electrodes 14 are connected to the second switch component. In actual application, a plurality of measurement electrodes can also be arranged in different areas of the insulation part (such as Figure 3 the other measurement positions 17 of the measurement electrodes shown in), and the insulation defect detection data can be measured simultaneously; a plurality of measurement electrodes can also be arranged in one area of the insulation part, and after the insulation defect detection data is measured, the insulation defect detection data of another area of the insulation part can be measured. In addition, the shape of the measurement electrode is cylindrical or annular; the size of the measurement electrode is determined based on the length of the stress cone area; for the measurement positions in the stress cone area, they are generally set at the length equal division points, and at least ensure that the number of measurement points in the stress cone area is greater than or equal to 2.

[0031] In another application example, both the first switch component 15 and the second switch component 16 are single-pole double-throw switches. The common terminal of the first switch component 15 is connected to the power supply component (specifically, a current-limiting resistor), the first output terminal of the first switch component 15 is grounded, and the second output terminal of the first switch component 15 is connected to the conductor part. The common terminal of the second switch component 16 is connected to the acquisition component, the first output terminal of the second switch component 16 is grounded, and the second output terminal of the second switch component 16 is connected to the electrode measurement component. By default, the first output terminals of the first switch component 15 and the second switch component 16 are both in a closed state, and the second output terminals of the first switch component 15 and the second switch component 16 are both in an open state.

[0032] In another application example, the acquisition component includes an operational amplifier, a capacitor, a first grounding resistor, a second grounding resistor, and a voltmeter; the first input terminal of the operational amplifier is grounded in series with the first grounding resistor; the second input terminal of the operational amplifier is connected to the second switch component; the output terminal of the operational amplifier is grounded in series with the second grounding resistor; the voltmeter is connected in parallel with the capacitor, one end of the voltmeter is connected to the second input terminal of the operational amplifier, and the other end of the voltmeter is connected to the output terminal of the operational amplifier.

[0033] In another application example, the control component includes a control terminal and an acquisition terminal. The control component is connected to a computer to achieve control of the control terminal and the acquisition terminal. Among them, the control terminal controls the opening and closing states of the first switch component 15 and the second switch component 16; the control terminal also controls the operating states of the power supply component and the acquisition component; the acquisition terminal performs analog-to-digital conversion processing and calculation on the insulation defect detection data fed back by the acquisition component.

[0034] Based on the same inventive concept, the embodiment of the present application also provides a method for detecting insulation defects of a submarine cable molded joint, as Figure 4 shown, the method includes:

[0035] Step 100, build the above-mentioned detection device for insulation defects of a submarine cable molded joint. In practical applications, before step 100, the method further includes: cleaning the insulation surface of the prepared submarine cable molded joint and fixing the position of the submarine cable molded joint to facilitate the subsequent installation of the non-destructive detection device.

[0036] Step 200, set the electrode measurement component in the body insulation area of the insulation part, and start the detection based on the control component to obtain the first insulation defect detection data corresponding to the body insulation area.

[0037] Step 300: Set the electrode measurement component in the restored insulation area of the insulation part, and start the detection based on the control component to obtain the second insulation defect detection data corresponding to the restored insulation area.

[0038] Step 400: Set the electrode measurement component in the stress cone area of the insulation part, and start the detection based on the control component to obtain the third insulation defect detection data corresponding to the stress cone area.

[0039] The detection processes of the above Step 200, Step 300, and Step 400 can be detected simultaneously or sequentially according to the different settings of the measurement electrodes (for example, first measure the body insulation area, and then measure the restored insulation area and the stress cone area to obtain the defect detection information at different positions of the submarine cable molded joint). However, the specific implementation processes of these three steps are the same. Taking Step 200 as an example, starting the detection based on the control component to obtain the first insulation defect detection data corresponding to the body insulation area includes:

[0040] (21) Send a collection status instruction to the collection component through the control component to make the opening and closing state of the collection component be open; that is, start the collection component.

[0041] (22) Send a first status instruction to the first switch component through the control component to make the opening and closing state of the first switch component be open; send a second status instruction to the second switch component through the control component to make the opening and closing state of the second switch component be open. Specifically, before this step, the single-pole single-throw of the first switch component 15 and the second switch component 16 is at the first output terminal; after receiving the instruction in this step, the single-pole single-throw of the first switch component 15 and the second switch component 16 is at the second output terminal.

[0042] (23) Send a voltage status instruction to the power supply component through the control component to change the voltage status data provided by the power supply component to the conductor part for realizing the detection; the voltage status data includes the measured voltage value and the measurement duration, such as setting the measurement duration t m greater than or equal to 1200 s. In addition, since the thickness of the restored insulation area is slightly greater than the thickness of the body insulation area, after calculation, when measuring at different positions, in order to ensure that the measured electric field strength is consistent, the voltage applied when measuring the restored insulation area and the insulation interface area is greater than the voltage applied when measuring the body insulation area. After the high-voltage DC power supply is turned on, the collection component collects and stores the insulation defect detection data of the submarine cable molded joint.

[0043] (24) Receive, through the control component, the insulation defect detection data fed back by the acquisition component during the test duration, so as to obtain the first insulation defect detection data corresponding to the insulation area of the body.

[0044] In an application example, step 200 may further be: Start the electrode measurement component and the acquisition component, synchronously switch the first switch component 15 and the second switch component 16 to the second output terminal, then turn on the high-voltage DC power supply in the power supply component, obtain the insulation defect detection data fed back by the acquisition component and transmit it to the control component; after reaching the measurement duration, turn off the high-voltage DC power supply, then the first switch component 15 and the second switch component 16 are reset to the first output terminal, and then turn off each component in the device.

[0045] Step 500, within the control component, evaluate the insulation performance of the submarine cable molded joint based on the first insulation defect detection data, the second insulation defect detection data, and the third insulation defect detection data, and obtain an evaluation result. Among them, the first insulation defect detection data, the second insulation defect detection data, and the third insulation defect detection data are all voltage-time change curves.

[0046] Step 500 includes:

[0047] (51) For any insulation defect detection data, determine the charge-time change curve according to the voltage-time change curve, and then extract a partial curve from the charge-time change curve and perform a linear function fitting to obtain a charge calculation function.

[0048] Specifically, based on the voltage-time change curve, calculate the charge-time change curve by inverse calculation according to the capacitance voltage calculation relationship, and the capacitance voltage calculation relationship is as follows:

[0049]

[0050] Among them, C0 is the capacitance value, q(t) is the charge quantity, and U(t) is the voltage value. Then, process the charge-time change curve, take the data from 1000s to 1200s in it for linear function fitting, and obtain the charge calculation function f(t). The range of the partial curve extracted for fitting can be adjusted as needed.

[0051] (52) Use the charge calculation function to determine the calculated charge f(0) at time 0, and determine the measured charge q(0) at time 0 according to the charge-time change curve, and then subtract the calculated charge at time 0 from the measured charge at time 0 to obtain the amount of space charge accumulation q inside the insulation s , as Figure 5 shown, the corresponding calculation formula is: q s = f(0) - q(0).

[0052] (53) Considering that the magnitudes of q(0) in each measurement result are not consistent, for the convenience of analysis, the insulation space charge accumulation rate g is defined. Specifically, according to the charge measured at the 0 moment and the amount of space charge accumulated inside the insulation, the corresponding insulation space charge accumulation rate is calculated; the calculation formula for the insulation space charge accumulation rate g is:

[0053]

[0054] (54) Taking the insulation space charge accumulation rate corresponding to the main body insulation region as a reference, respectively combining the insulation space charge accumulation rate corresponding to the restored insulation region and the insulation space charge accumulation rate corresponding to the stress cone region, the measurement position deviation percentage is calculated; the calculation formula for the measurement position deviation percentage k is:

[0055]

[0056] where g bulk is the insulation space charge accumulation rate corresponding to the main body insulation region, and g joint is the insulation space charge accumulation rate corresponding to the restored insulation region or the insulation space charge accumulation rate corresponding to the stress cone region.

[0057] (55) If all the measurement position deviation percentages are less than or equal to the preset value, a first evaluation result is obtained; the first evaluation result indicates that the insulation performance of the submarine cable molded joint is qualified.

[0058] (56) If any of the measurement position deviation percentages is greater than the preset value, a second evaluation result is obtained; the second evaluation result indicates that the insulation performance of the submarine cable molded joint is unqualified; the preset value can be set to 105%. That is, if the deviation percentage k is greater than 105%, it proves that there is a more significant space charge accumulation phenomenon in the restored insulation region and the stress cone region of the submarine cable molded joint than in the main body insulation region, and the insulation performance of the submarine cable molded joint is poor. In this case, relevant technicians can find the corresponding measurement positions, re-measure and analyze the results; if it still does not meet the requirements, check the joint preparation process parameters and production process, and re-manufacture the submarine cable molded joint.

[0059] In another specific exemplary application, the present application also provides an example of non-destructive testing for the insulation part of a 220 kV high-voltage submarine circuit molded joint. Among them, the schematic diagram of the specific structure and test positions of the submarine cable molded joint is as Figure 6As shown, the thickness of the body insulation area of the submarine cable molded joint is 27 mm, the thickness of the restored insulation area is 28 mm, and the length of the stress cone area is 88 mm. At room temperature, when measuring the body insulation area and the restored insulation area of the submarine cable molded joint, the applied electric field strength is 10 kV / mm; the measurement duration t m is set to 1200 s; the number of measurement points in the stress cone area is 2, the electrode shape is selected as cylindrical, and the diameter of the cylindrical electrode surface is 30 mm.

[0060] Based on the above initial settings, after detecting using the solution of this application, the test results of the internal space charge accumulation rate of the insulation of the submarine cable molded joint are shown in Table 1, and the insulation deviation percentage k results of the submarine cable molded joint are shown in Table 2; analyzing based on Table 1 and Table 2, it can be known that: in the stress cone area of the submarine cable molded joint, when the interface is located inside the insulation, the space charge accumulation rate is significantly increased compared to the body insulation (>105%). The analysis may be that during the injection molding preparation process of the molded joint insulation, the temperature near the conductor is relatively low, resulting in poor welding performance between the body insulation and the restored insulation, and then introducing interface defects. For this, relevant technical personnel can correct the preparation process to avoid the generation of interface defects.

[0061] Table 1

[0062]

[0063] Table 2

[0064]

[0065] The technical features of the above embodiments can be combined arbitrarily. For the sake of concise description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this specification.

[0066] In this article, specific examples are used to elaborate on the principle and implementation manner of this application. The description of the above embodiments is only used to help understand the method and its core idea of this application; at the same time, for those of ordinary skill in the art, based on the idea of this application, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to this application.

Claims

1. A detection device for insulation defects of a submarine cable molded joint, connected to a submarine cable molded joint, wherein the submarine cable molded joint comprises a conductor part and an insulation part, and is characterized in that: The device for detecting insulation defects of submarine cable molded joints comprises a power supply component, a first switch component, a second switch component, an electrode measurement component, a collection component and a control component; the insulation part comprises a body insulation area, a recovery insulation area and a reaction force cone area; The power supply component is connected to the conductor part through the first switch component; the collection component is connected to the electrode measurement component through the second switch component, and the electrode measurement component is arranged in any area of ​​the body insulation area, the recovery insulation area and the reaction force cone area; the control component is respectively connected to the power supply component, the first switch component, the second switch component and the collection component; The control component is used to: send a first state instruction to the first switch component to change the on / off state of the first switch component; send a second state instruction to the second switch component to change the on / off state of the second switch component; send a voltage state instruction to the power supply component to change the voltage state data provided by the power supply component to the conductor part for detection; send a collection state instruction to the acquisition component to change the on / off state of the acquisition component; receive and store the insulation defect detection data fed back by the acquisition component, and evaluate the insulation performance of the submarine cable molded joint according to the insulation defect detection data corresponding to different areas; the insulation defect detection data is obtained through the electrode measurement component and the second switch component when the on / off state of the acquisition component is on; The first switch component and the second switch component are both single-pole double-throw switches; the common terminal of the first switch component is connected to the power supply component, the first output end of the first switch component is grounded, and the second output end of the first switch component is connected to the conductor part; the common terminal of the second switch component is connected to the acquisition component, the first output end of the second switch component is grounded, and the second output end of the second switch component is connected to the electrode measurement component; Based on the evaluation results, the corresponding measurement locations can be found, remeasured and the results analyzed; If it still does not meet the requirements, check the joint preparation process parameters and production process, and remake the submarine cable molded joint.

2. The device for detecting insulation defects of submarine cable molded joints according to claim 1 is characterized in that: The power supply assembly comprises a high-voltage DC power supply and a current-limiting resistor; the high-voltage DC power supply, the current-limiting resistor, the first switch component and the conductor part are connected in series in sequence; The high-voltage DC power supply is used to provide a voltage within a preset voltage range for the conductor part.

3. The device for detecting insulation defects of submarine cable molded joints according to claim 1 is characterized in that: The electrode measurement assembly comprises a plurality of measurement electrodes and an electrode fixing fixture corresponding to each of the measurement electrodes; the electrode fixing fixture is used to fix the measurement electrode on the insulating part; All of the measuring electrodes are connected to the second switch element.

4. The device for detecting insulation defects of submarine cable molded joints according to claim 3 is characterized in that: The shape of the measuring electrode is cylindrical or annular; the size of the measuring electrode is determined based on the length of the reaction force cone area.

5. The device for detecting insulation defects of submarine cable molded joints according to claim 1, characterized in that: The acquisition component includes an operational amplifier, a capacitor, a first grounding resistor, a second grounding resistor and a voltmeter; The first input terminal of the operational amplifier is connected in series with the first grounding resistor and then grounded; the second input terminal of the operational amplifier is connected to the second switch component; the output terminal of the operational amplifier is connected in series with the second grounding resistor and then grounded; the voltmeter is connected in parallel with the capacitor, one end of the voltmeter is connected to the second input terminal of the operational amplifier, and the other end of the voltmeter is connected to the output terminal of the operational amplifier.

6. A method for detecting insulation defects of submarine cable molded joints, characterized in that: The method for detecting insulation defects of submarine cable molded joints comprises: Constructing a detection device for insulation defects of a submarine cable molded joint as described in any one of claims 1 to 5; The electrode measurement component is arranged in the main body insulation area of ​​the insulation part, and the detection is started based on the control component to obtain the first insulation defect detection data corresponding to the main body insulation area; The electrode measurement component is arranged in the insulation recovery area of ​​the insulation part, and detection is started based on the control component to obtain second insulation defect detection data corresponding to the insulation recovery area; The electrode measurement component is arranged in the reaction force cone area of ​​the insulating part, and detection is started based on the control component to obtain third insulation defect detection data corresponding to the reaction force cone area; In the control component, based on the first insulation defect detection data, the second insulation defect detection data and the third insulation defect detection data, the insulation performance of the submarine cable molded joint is evaluated and an evaluation result is obtained.

7. The method for detecting insulation defects of submarine cable molded joints according to claim 6, characterized in that: Based on the control component starting detection, obtaining first insulation defect detection data corresponding to the insulation area of ​​the body includes: Sending a collection state instruction to the collection component through the control component, so that the opening and closing state of the collection component is opened; Sending a first state instruction to the first switch component through the control component so that the on / off state of the first switch component is turned on; sending a second state instruction to the second switch component through the control component so that the on / off state of the second switch component is turned on; Sending a voltage state instruction to the power supply component through the control component to change the voltage state data provided by the power supply component to the conductor part for detection; the voltage state data includes a measured voltage value and a measurement duration; The control component receives the insulation defect detection data fed back by the acquisition component within the measurement time period to obtain first insulation defect detection data corresponding to the main body insulation area.

8. The method for detecting insulation defects of submarine cable molded joints according to claim 6, characterized in that: The first insulation defect detection data, the second insulation defect detection data and the third insulation defect detection data are all voltage-time variation curves; Based on the first insulation defect detection data, the second insulation defect detection data and the third insulation defect detection data, the insulation performance of the submarine cable molded joint is evaluated and an evaluation result is obtained, including: For any insulation defect detection data, a charge-time variation curve is determined according to the voltage-time variation curve, and then a part of the curve is extracted from the charge-time variation curve and a function fitting is performed to obtain a charge calculation function; The charge calculation function is used to determine the calculated charge at time 0, and the measured charge at time 0 is determined according to the charge-time variation curve, and then the calculated charge at time 0 is subtracted from the measured charge at time 0 to obtain the charge accumulation amount in the insulation internal space; Calculate the corresponding insulation space charge accumulation rate according to the charge measured at time 0 and the charge accumulation amount in the insulation internal space; Taking the insulation space charge accumulation rate corresponding to the main insulation area as a reference, respectively combining the insulation space charge accumulation rate corresponding to the recovery insulation area and the insulation space charge accumulation rate corresponding to the reaction force cone area, calculate the measurement position deviation percentage; If all the measurement position deviation percentages are less than or equal to the preset value, a first evaluation result is obtained; the first evaluation result indicates that the insulation performance of the submarine cable molded joint is qualified; If the deviation percentage of any of the measurement positions is greater than a preset value, a second evaluation result is obtained; the second evaluation result indicates that the insulation performance of the submarine cable molded joint is unqualified.

9. The method for detecting insulation defects of submarine cable molded joints according to claim 8, characterized in that: The calculation formula of the insulation space charge accumulation rate g is: Among them, q(0) is the charge measured at time 0, q s is the amount of charge accumulated in the insulation space; The calculation formula of the measurement position deviation percentage k is: Among them, g bulk is the insulation space charge accumulation rate corresponding to the bulk insulation region, g joint To restore the insulation space charge accumulation rate corresponding to the insulation area or the insulation space charge accumulation rate corresponding to the reaction force cone area.

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