Device and method for detecting insulation defect of submarine cable molded joint

Abstract

The invention discloses a submarine cable molded joint insulation defect detection device and method, and relates to the field of electrical equipment insulation detection, and the device comprises a power supply assembly, a first switch part, a second switch part, an electrode measurement assembly, an acquisition assembly and a control assembly. The control assembly is used for sending a first state instruction to the first switch part to change the opening and closing state; a second state instruction is sent to the second switch component to change the opening and closing state; sending a voltage state instruction to a power supply assembly to change voltage state data provided for the conductor part for realizing detection; sending an acquisition state instruction to the acquisition assembly to change the on-off state; and receiving and storing the insulation defect detection data fed back by the acquisition assembly, and evaluating the insulation performance of the submarine cable molded joint according to the insulation defect detection data corresponding to different areas. According to the invention, nondestructive and timely detection of the insulation defect of the submarine cable molded joint is realized.

Description

Technical Field

[0001] The present application relates to the field of insulation detection of electrical equipment, and in particular to a device and method for detecting insulation defects of submarine cable molded joints. Background Art

[0002] High-voltage submarine cables are crucial for long-distance cross-sea power transmission. At present, the manufacturing length of a single submarine cable is limited. As the core component of the flexible connection of long submarine cable lines, molded joints have higher requirements on the reliability of molded joint insulation with the rapid development of offshore wind power in deep waters. The insulation of molded joints is mainly composed of two parts: main insulation and recovery insulation. Although the recovery insulation uses the same insulating medium as the main insulation, due to problems with the manufacturing process, interface defects are still inevitable between the main insulation and the recovery insulation, which leads to a serious decrease in the insulation performance of the molded joint, and the defects need to be detected. Existing cable joint defect detection is mainly based on X-ray imaging, withstand voltage test, partial discharge test, etc., but it is inevitable to damage the material structure or insulation performance. Summary of the invention

[0003] The purpose of the present application is to provide a device and method for detecting 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 objectives, this application provides the following solutions:

[0005] In a first aspect, the present application provides a detection device for insulation defects of a submarine cable molded joint, which is connected to a submarine cable molded joint, wherein the submarine cable molded joint includes a conductor portion and an insulation portion, and 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 portion includes a body insulation area, a recovery insulation area, and a reaction force 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 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;

[0007] 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 via the electrode measurement component and the second switch component when the on-off state of the acquisition component is on.

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

[0009] Build a detection device for insulation defects of submarine cable molded joints;

[0010] 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;

[0011] 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;

[0012] 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;

[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, the insulation performance of the submarine cable molded joint is evaluated and an evaluation result is obtained.

[0014] According to the specific embodiments provided by the present application, the present application has the following technical effects: the present application provides a device and method for detecting insulation defects of submarine cable molded joints, and 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 area of ​​the body insulation area, the recovery insulation area and the reaction force cone area. The above structure is controlled by the control component for opening and closing, state adjustment, and receiving and storing the insulation defect detection data fed back by the acquisition component, and the insulation performance of the submarine cable molded joint is evaluated according to the insulation defect detection data corresponding to different areas. The device of the present application realizes the detection of insulation defects of submarine cable molded joints by electrical control of each component, and will not damage the material structure or insulation performance, thereby realizing non-destructive testing. Moreover, in the present application, the voltage provided by the power supply component is used as the detection basis, which can ensure the timeliness of subsequent detection and directly obtain the corresponding insulation defect detection data. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0016] Figure 1 This is a schematic diagram of the structure of a submarine cable molded joint in one embodiment of the present application;

[0017] Figure 2 A schematic diagram of a setting area of ​​a measuring electrode in an embodiment of the present application;

[0018] Figure 3 A schematic diagram of a device for detecting insulation defects of a submarine cable molded joint provided in one embodiment of the present application;

[0019] Figure 4 A schematic flow chart of a method for detecting insulation defects of a submarine cable molded joint provided in one embodiment of the present application;

[0020] Figure 5 This is a schematic diagram of calculating the amount of charge accumulation in the insulation internal space in one embodiment of the present application;

[0021] Figure 6 Schematic diagram of insulation dimensions and measurement positions of a submarine cable molded joint in one embodiment of the present application.

[0022] Figure markings: 1-outer sheath, 2-metal shielding, 3-insulating interface, 4-restoring insulation area, 5-conductor shielding area, 6-body insulation area, 7-insulating shielding area, 8-conductor part, 9-reaction force 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 DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0024] For submarine cable molded joints, this application provides a non-destructive detection method for insulation defects, which is performed after the insulation part is prepared, providing guarantees for the design, preparation and safe operation of submarine cable molded joints, and timely and fundamentally eliminating the impact of insulation defects.

[0025] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[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 a submarine cable molded joint 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 detection device for insulation defects of a submarine cable molded joint is connected to the submarine cable molded joint to realize corresponding insulation defect detection. The submarine cable molded joint comprises a conductor part 8 and an insulation part, specifically as Figure 1 and Figure 2 As shown, the submarine cable molded joint comprises an outer sheath 1, a metal shield 2, an insulation interface 3, a recovery insulation area 4, a conductor shield area 5, a body insulation area 6, an insulation shield area 7, a conductor portion 8 and a reaction force cone area 9. A first outer interface 10, a first inner interface 11, a second inner interface 12 and a second outer interface 13 can also be divided on both sides of the recovery insulation area.

[0027] Based on the above structure, the present application provides the following Figure 3As shown in the schematic diagram, 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 area of ​​the main 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 acquisition component.

[0028] The control component is used to: send a first state instruction to the first switch component 15 to change the opening and closing state of the first switch component 15; send a second state instruction to the second switch component 16 to change the opening and closing state of the second switch component 16; 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 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 via 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 assembly 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 the conductor part with a voltage within a preset voltage range, that is, the voltage provided by the high-voltage DC power supply is adjustable, and the preset voltage range can be 0kV to 300kV.

[0030] In another application example, the electrode measurement assembly includes a plurality of measuring electrodes 14 and an electrode fixing fixture corresponding to each measuring electrode; the electrode fixing fixture is used to fix the measuring electrode 14 on the insulating part, that is, the measuring electrode 14 is directly insulated from the submarine cable molded joint; all the measuring electrodes 14 are connected to the second switch component. In practical applications, multiple measuring electrodes can also be arranged in different areas of the insulating part (such as Figure 3 The other measuring positions 17 of the measuring electrodes shown in the figure are used to measure the insulation defect detection data at the same time; multiple measuring electrodes can also be set in one area of ​​the insulation part, and after completing the measurement of the insulation defect detection data, the insulation defect detection data of another area of ​​the insulation part is measured. In addition, 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; the measurement position of the reaction force cone area is generally set at the length equalizing point, and at least the number of measurement points in the reaction force cone area is greater than or equal to 2.

[0031] In another application example, the first switch component 15 and the second switch component 16 are both 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 end of the first switch component 15 is grounded, and the second output end of the first switch component 15 is connected to the conductor portion. The common terminal of the second switch component 16 is connected to the acquisition component, the first output end of the second switch component 16 is grounded, and the second output end of the second switch component 16 is connected to the electrode measurement component. By default, the first output end of the first switch component 15 and the first output end of the second switch component 16 are both in a closed state, and the second output end of the first switch component 15 and the second output end of 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 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.

[0033] In another application example, the control component includes a control terminal and a collection terminal, and the control component is connected to a computer to control the control terminal and the collection terminal. The control terminal controls the on / off state of the first switch component 15 and the second switch component 16; the control terminal also controls the operation state of the power supply component and the collection component; the collection terminal performs analog-to-digital conversion and calculation on the insulation defect detection data fed back by the collection component.

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

[0035] Step 100, construct the above-mentioned submarine cable molded joint insulation defect detection device. 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: dispose an electrode measurement component in a main body insulation region of an insulation part, and start detection based on a control component to obtain first insulation defect detection data corresponding to the main body insulation region.

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

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

[0039] The detection process of the above steps 200, 300 and 400 can be detected simultaneously or sequentially according to the different setting areas of the measuring electrodes (such as first measuring the body insulation area, then measuring the recovery insulation area and the reaction force cone area, and obtaining defect detection information at different positions of the submarine cable molded joint), but the specific implementation process of these three steps is the same. Taking step 200 as an example, in step 200, the detection is started based on the control component to obtain the first insulation defect detection data corresponding to the body insulation area, including:

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

[0041] (22) 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. Specifically, before this step, the single-pole throw of the first switch component 15 and the second switch component 16 is at the first output end; after receiving the instruction in this step, the single-pole throw of the first switch component 15 and the second switch component 16 is at the second output end.

[0042] (23) 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 the measured voltage value and the measurement time, such as setting the measurement time t m Greater than or equal to 1200s. In addition, since the thickness of the restored insulation area is slightly greater than that of the main insulation area, after calculation, when measuring at different positions, in order to ensure the consistency of the measured electric field strength, the voltage applied when measuring the restored insulation area and the insulation interface area is greater than the voltage applied when measuring the main insulation area. After the high-voltage DC power supply is turned on, the acquisition component collects and stores the insulation defect detection data of the submarine cable molded joint.

[0043] (24) receiving, through the control component, insulation defect detection data fed back by the acquisition component within the test duration, to obtain first insulation defect detection data corresponding to the main body insulation area.

[0044] In an application example, step 200 can also 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 end, 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 the measurement time is reached, turn off the high-voltage DC power supply, then reset the first switch component 15 and the second switch component 16 to the first output end, and then turn off each component in the device.

[0045] Step 500: 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. 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.

[0046] Step 500 includes:

[0047] (51) For any insulation defect detection data, a charge-time variation curve is determined according to the voltage-time variation curve, and then a partial curve is extracted from the charge-time variation curve and a function fitting is performed to obtain a charge calculation function.

[0048] Specifically, based on the voltage-time variation curve, the charge-time variation curve is obtained by inverse calculation according to the capacitance-voltage calculation relationship. The capacitance-voltage calculation relationship is as follows:

[0049]

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

[0051] (52) The charge calculation function is used to determine the calculated charge f(0) at time 0, and the measured charge q(0) 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 q in the insulation internal space s ,like Figure 5 As shown, the corresponding calculation formula is: s =f(0)-q(0).

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

[0053]

[0054] (54) Taking the insulation space charge accumulation rate corresponding to the main insulation area as a reference, 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 are respectively combined to calculate the measurement position deviation percentage; the calculation formula of the measurement position deviation percentage k is:

[0055]

[0056] Among them, g bulk is the insulation space charge accumulation rate corresponding to the bulk insulation region, g joint To restore the insulating space charge accumulation rate corresponding to the insulating area or the insulating space charge accumulation rate corresponding to the reaction force cone area.

[0057] (55) If all the measurement position deviation percentages are less than or equal to a 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 the deviation percentage of any of the measurement positions 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 the insulation of the recovery insulation area and the reaction force cone area of ​​the submarine cable molded joint has a more significant space charge accumulation phenomenon than the main body insulation area, and the insulation performance of the submarine cable molded joint is poor. In this case, the relevant technicians can find the corresponding measurement position, 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-make the submarine cable molded joint.

[0059] In another specific exemplary application, the present application also provides an example of non-destructive testing of the insulation part of a 220kV high voltage submarine circuit molded joint. Figure 6As shown in the figure, the thickness of the main insulation area of ​​the submarine cable molded joint is 27mm, the thickness of the recovery insulation area is 28mm, and the length of the reaction force cone area is 88mm. At room temperature, when measuring the main insulation area and the recovery insulation area of ​​the submarine cable molded joint, the applied field strength is guaranteed to be 10kV / mm; set the measurement time t m The reaction time is 1200s; the number of measurement points in the reaction force cone area is 2, the electrode shape is selected to be cylindrical, and the diameter of the cylindrical electrode surface is 30mm.

[0060] Based on the above initial settings, after testing using the scheme of this application, the test results of the insulation internal space charge accumulation rate of the submarine cable molded joint are shown in Table 1, and the insulation deviation percentage k of the submarine cable molded joint is shown in Table 2; Based on the analysis of Tables 1 and 2, it can be seen that: in the reaction force cone area of ​​the submarine cable molded joint, when the interface is located on the inner side of the insulation, the space charge accumulation rate is significantly increased compared to the bulk insulation (>105%). The analysis may be due to the low temperature near the conductor during the injection molding preparation of the molded joint insulation, resulting in poor welding performance of the bulk insulation and the restored insulation, which in turn introduces interface defects. For this, relevant technicians can modify 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 may be combined arbitrarily. To make the description concise, 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, they should be considered to be within the scope of this specification.

[0066] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core ideas of this application. At the same time, for those skilled in the art, according to the ideas of this application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting 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 via the electrode measurement component and the second switch component when the on-off state of the acquisition component is on.

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 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 assembly, 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.

4. 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.

5. The device for detecting insulation defects of submarine cable molded joints according to claim 4 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.

6. 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.

7. 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 6; 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.

8. The method for detecting insulation defects of submarine cable molded joints according to claim 7, 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 test duration to obtain first insulation defect detection data corresponding to the main body insulation area.

9. The method for detecting insulation defects of submarine cable molded joints according to claim 7, 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.

10. The method for detecting insulation defects of submarine cable molded joints according to claim 9, 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 insulating space charge accumulation rate corresponding to the insulating area or the insulating space charge accumulation rate corresponding to the reaction force cone area.

Images