Cable bushing and cable voltage detection device

Abstract

The application relates to a cable sleeve and a cable voltage detection device. The cable sleeve comprises a sleeve and a voltage division film. The sleeve is sleeved on the periphery of an insulating sleeve of a cable and is spaced from the insulating sleeve. The voltage division film is filled between the sleeve and the insulating sleeve. The voltage division film comprises, from inside to outside along the radial direction of the cable sleeve, a first metal layer, an insulating layer and a second metal layer. The first metal layer and the second metal layer are at least partially attached to the outer peripheral surface of the insulating sleeve and the inner peripheral surface of the sleeve respectively. The second metal layer is used for conduction with a ground wire. The first metal layer is used for conduction with a load. The potential of the load is greater than zero potential and smaller than the potential of a core wire of the cable. One electrode of a first capacitor of the cable sleeve of the application is the core wire of the cable, which has a higher potential. One electrode of a second capacitor is grounded. The first capacitor and the second capacitor are connected in series for voltage division, so that the first metal layer has a low potential. The first metal layer is connected to the load, which can meet the voltage requirement of the load.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of cable bushings, in particular to a cable bushing and a cable voltage detection device. BACKGROUND

[0002] The voltage in the cable is usually high, and the use equipment or the measuring equipment often cannot be directly connected with the cable, and because there is a rapidly changing impulse voltage in the cable, the resistance is less sensitive to the high-frequency impulse voltage, and it is difficult to detect the high-frequency impulse voltage. SUMMARY

[0003] In view of the above-mentioned technical problems, the purpose of the present application is to provide a cable bushing with a capacitive voltage division and a cable voltage detection device comprising the above-mentioned cable bushing, specifically comprising the following technical solutions:

[0004] In a first aspect, the present application provides a cable bushing, comprising a sleeve and a voltage division film, the sleeve is sleeved on the periphery of the insulating sleeve of the cable and is spaced from the insulating sleeve, the voltage division film is filled between the sleeve and the insulating sleeve, and the voltage division film comprises a first metal layer, an insulating layer and a second metal layer arranged in order from inside to outside along the radial direction of the cable bushing, the first metal layer and the second metal layer are at least partially attached to the outer peripheral surface of the insulating sleeve and the inner peripheral surface of the sleeve respectively, the second metal layer is used for conducting with the ground wire, and the first metal layer is used for conducting with the load, the potential of the load is greater than the zero potential and less than the potential of the core wire of the cable.

[0005] The cable bushing of the present application can form two capacitors (first capacitor and second capacitor), the first metal layer of the cable bushing and the core wire of the cable serve as two electrodes of the first capacitor, and the insulating layer of the cable serves as an insulating medium between the two electrodes of the first capacitor to form the first capacitor; the second metal layer and the first metal layer serve as two electrodes of the second capacitor, and the insulating layer of the voltage division film serves as an insulating medium between the two electrodes of the second capacitor to form the second capacitor.

[0006] One electrode of the first capacitor of the cable bushing of the present application is the core wire of the cable, which has a high potential (high potential), and one electrode of the second capacitor is grounded (zero potential), the first capacitor and the second capacitor are connected in series to divide the voltage, so that the first metal layer serving as the electrode of the first capacitor and the second capacitor has a low potential, the first metal layer is connected with the load, and the voltage requirement of the load can be met.

[0007] In an embodiment, the sleeve is provided with a through hole along the radial direction of the cable bushing, and the cable bushing comprises a conductive piece, the conductive piece is at least partially located in the through hole, one end of the conductive piece is used for conducting with the first metal layer, and the other end of the conductive piece extends out of the sleeve for conducting with the load.

[0008] In the embodiment, one end of the conductive member is in conductive connection with the first metal layer, and the other end extends to the outside of the sleeve, so that the load is directly connected to the end of the conductive member outside the sleeve, and the load is in conductive connection with the first metal layer on the opposite inner side.

[0009] In an embodiment, the second metal layer and the insulating layer along the radial direction of the cable sleeve are respectively provided with a first avoiding hole and a second avoiding hole, the first avoiding hole is communicated between the through hole and the second avoiding hole, and the first avoiding hole and the second avoiding hole are used to expose part of the first metal layer, so as to facilitate the conductive connection of the first metal layer and the conductive member.

[0010] In the embodiment, the first avoiding hole and the second avoiding hole expose part of the first metal layer, and the exposed first metal layer facilitates the conductive connection with the conductive member.

[0011] In an embodiment, the first metal layer includes a first protruding portion extending away from the cable, the first protruding portion passes through the first avoiding hole and the second avoiding hole, and is used to form at least part of the conductive member.

[0012] In the embodiment, the first protruding portion can pass through the insulating layer and the second metal layer to form part of the conductive member, so as to facilitate the conductive connection of the load and the first metal layer on the opposite inner side.

[0013] In an embodiment, at least one splicing seam is formed on the voltage dividing film along the circumferential direction of the cable sleeve, the splicing seam extends along the axial direction of the cable sleeve, and the through hole is communicated with the splicing seam, the conductive member passes through the splicing seam to be in conductive connection with the first metal layer, and the outer side of the conductive member is sleeved with an insulating sheath to separate the conductive member from the second metal layer.

[0014] In the embodiment, one voltage dividing film is arranged outside the insulating sleeve of the cable, and the voltage dividing film is spliced at both ends along the circumferential direction of the cable sleeve; or a plurality of voltage dividing films are arranged outside the insulating sleeve of the cable, and the end portions of the plurality of voltage dividing films are spliced, and the splicing portions of the voltage dividing films form splicing seams, the conductive member passes through the splicing seams and is in conductive connection with the first metal layer. The insulating sheath is used to prevent the second metal layer from being in conductive connection with the conductive member, thereby avoiding the failure of the capacitive voltage division of the cable sleeve.

[0015] In an embodiment, the cable sleeve includes a plurality of conductive members and a plurality of insulating sheaths, the plurality of conductive members are arranged at intervals along the extension direction of the splicing seam, each conductive member is in conductive connection between the first metal layer and the load, and the outer side of each conductive member is sleeved with an insulating sheath to separate the conductive member from the second metal layer.

[0016] In the embodiment, the plurality of conductive members are arranged at intervals along the extension direction of the splicing seam and are in conductive connection between the first metal layer and the load, so that the failure of a single conductive member does not cause the cable sleeve to fail to work normally. The insulating sheath is used to prevent the second metal layer from being in conductive connection with the conductive member and the two adjacent conductive members.

[0017] In an embodiment, the cable sleeve comprises a resistance, the resistance is fixed in the through hole, and the resistance is in series with the conductive part.

[0018] In the embodiment, the resistance is in series with the conductive part to make the resistance in series with the load, and the resistance can perform resistance voltage division after two capacitor voltage divisions to further reduce the voltage of the load.

[0019] In an embodiment, the resistance value of the resistance is adjustable.

[0020] It can be understood that the capacitances of the two capacitors of the cable sleeve are related to the voltage division film and the cable, that is, the voltage division ratio of the capacitor voltage division is difficult to change, and adjusting the resistance value of the resistance can change the voltage of the load to adapt to different loads in different occasions.

[0021] In an embodiment, the insulating layer comprises a second protruding part, the second protruding part extends towards the second metal layer, and the second protruding part is arranged around the outside of the conductive part to separate the conductive part from the second metal layer.

[0022] In the embodiment, the second protruding part is arranged around the outside of the conductive part to separate the conductive part from the second metal layer, prevent the second metal layer from being in conduction with the conductive part, and further avoid the capacitor voltage division of the cable sleeve from being invalid.

[0023] In an embodiment, the material of the inner circumferential surface of the sleeve comprises a conductive material, and the second metal layer is in conduction with the ground wire through the sleeve.

[0024] In the embodiment, the material of the inner circumferential surface of the sleeve comprises a conductive material, the inner circumferential surface of the sleeve is attached to the second metal layer to make the second metal layer in conduction with the sleeve, the sleeve is located on the opposite outside of the cable sleeve, and the conduction between the second metal layer and the ground wire is facilitated by connecting the ground wire through the sleeve.

[0025] In an embodiment, the voltage division film is at least partially exposed on the outside of the sleeve along the axial direction of the cable sleeve, and the exposed area of the second metal layer is used for conduction with the ground wire.

[0026] In the embodiment, the voltage division film is at least partially located on the outside of the sleeve to facilitate the conduction between the second metal layer and the ground wire, and further realize the capacitor voltage division of the cable sleeve.

[0027] In an embodiment, the sleeve comprises at least two arc-shaped housings arranged along the circumferential direction of the cable sleeve, the two arc-shaped housings adjacent along the circumferential direction of the cable sleeve are fixedly connected, and the radius corresponding to each arc-shaped housing is less than or equal to the sum of the outer circumferential surface radius of the insulating sleeve and the thickness of the voltage division film.

[0028] In the embodiment, the sleeve is divided into arc-shaped shells so as to be sleeved outside the voltage-dividing film, and the radius of the arc-shaped shells is less than the sum of the radius of the outer circumferential surface of the insulating sleeve and the thickness of the voltage-dividing film, so that the arc-shaped shells can clamp the voltage-dividing film and the voltage-dividing film can be closely attached to the insulating sleeve.

[0029] In an embodiment, the sum of the central angles corresponding to the arc-shaped shells is less than 360°.

[0030] In the embodiment, the sum of the central angles corresponding to the arc-shaped shells is less than 360°, so that gaps are left between the arc-shaped shells along the circumferential direction of the cable sleeve to accommodate part of the voltage-dividing film.

[0031] In a second aspect, the embodiment of the application further provides a cable voltage detection device, which comprises a voltmeter and the cable sleeve described above, the cable sleeve is sleeved outside the insulating sleeve of the cable, and the two poles of the voltmeter are respectively in conduction with the first metal layer and the second metal layer of the cable sleeve.

[0032] It can be understood that, due to the adoption of the cable sleeve described above, the cable voltage detection device of the application can reduce the steps required for voltage detection and improve the detection accuracy for impulse voltage.

[0033] In an embodiment, the cable sleeve comprises a resistance and a transmission line, the resistance and the transmission line are used in series with the voltmeter, and the ratio of the resistance value of the resistance to the wave impedance of the transmission line ranges from 10 to 120.

[0034] In the embodiment, the voltage of the cable is divided by the capacitor and then divided by the resistance and the transmission line, and the detection result of the voltmeter can be used to obtain the voltage of the cable. In addition, the ratio of the resistance value of the resistance to the wave impedance of the transmission line can reduce the influence of the load effect on the detection result of the voltmeter. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 FIG. 1 is a structural schematic diagram of a cable sleeve with a cable according to an embodiment of the application from one perspective;

[0036] Figure 2 FIG. 2 is a structural schematic diagram of the cable sleeve with the cable according to the embodiment of the application from another perspective;

[0037] Figure 3 FIG. 3 is a partial structural schematic diagram of a voltage-dividing film in a flat state according to an embodiment of the application;

[0038] Figure 4 FIG. 4 is a partial cross-sectional schematic diagram of the voltage-dividing film in the flat state according to the embodiment of the application;

[0039] Figure 5A partial cross-sectional view of a cable bushing with a cable according to an embodiment of the present application;

[0040] Figure 6 A partial cross-sectional view of a cable bushing with a cable according to another embodiment of the present application;

[0041] Figure 7 A partial cross-sectional view of a cable bushing with a cable according to another embodiment of the present application;

[0042] Figure 8 A partial cross-sectional view of a cable bushing with a cable according to another embodiment of the present application;

[0043] Figure 9 A partial cross-sectional view of a cable bushing with a cable according to another embodiment of the present application. DETAILED DESCRIPTION

[0044] In order to facilitate the understanding of the present application, a more complete understanding of the present application can be had by reference to the following description and the accompanying drawings. The figures included in the application are intended to highlight only certain aspects of the application. However, the application can be practiced without all of the aspects of the application described. In other words, the application can be practiced using only some of the aspects of the application described. In addition, the figures are not necessarily drawn to scale. The figures are intended to illustrate the principles of the application.

[0045] The following description of several embodiments is with reference to the drawings, which illustrate particular embodiments of the application. The description herein of any part of the components, such as "first", "second", etc., is only used to distinguish the described object, and does not have any sequential or technical meaning. The "connection" and "coupling" mentioned in the present application, unless otherwise specified, includes direct and indirect connection (coupling). The direction terms mentioned in the present application, such as "up", "down", "front", "back", "left", "right", "inside", "outside", "side", etc., are only with reference to the direction of the attached drawings, therefore, the direction terms used are for better, clearer illustration and understanding of the present application, and are not indicative or implied that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0046] The core voltage of the cable is high, and it is difficult to be directly connected to the load. For this purpose, the present application provides a cable bushing 100, which can reduce the voltage of the core of the cable, and the voltage output by the cable bushing 100 meets the voltage requirement of the load.

[0047] Please refer to Figure 1 and Figure 2 wherein, Figure 1A structural schematic diagram illustrating a perspective of the cable bushing 100 provided in an embodiment of the present application with the cable 110; Figure 2 A structural schematic diagram illustrating another perspective of the cable bushing 100 provided in an embodiment of the present application with the cable 110.

[0048] The cable bushing 100 provided in the present application comprises a sleeve 10 and a voltage dividing film 20, the sleeve 10 is sleeved on the outer periphery of the insulating sleeve 112 of the cable 110 and is spaced from the insulating sleeve 112, and the voltage dividing film 20 is filled between the sleeve 10 and the insulating sleeve 112.

[0049] Specifically, in the cable bushing 100 provided in the present application, Figure 1 and Figure 2 , the voltage dividing film 20 is arranged around the outside of the insulating sleeve 112 of the cable 110, the sleeve 10 comprises a first arc-shaped shell 11 and a second arc-shaped shell 12, the first arc-shaped shell 11 and the second arc-shaped shell 12 are respectively located on two sides of the voltage dividing film 20 along the radial direction of the cable bushing 100, and the first arc-shaped shell 11 and the second arc-shaped shell 12 are fixedly connected and clamp the voltage dividing film 20, thereby limiting the axial displacement of the voltage dividing film 20 along the cable bushing 100.

[0050] Please refer to Figure 3 A partial structural schematic diagram illustrating the voltage dividing film 20 in a flat state provided in an embodiment of the present application.

[0051] The voltage dividing film 20 of the cable bushing 100 provided in the present application comprises a first metal layer 21, an insulating layer 22 and a second metal layer 23 arranged in sequence from inside to outside along the radial direction of the cable bushing 100, the first metal layer 21 and the second metal layer 23 are respectively at least partially attached to the outer peripheral surface of the insulating sleeve 112 and the inner peripheral surface of the sleeve 10, the second metal layer 23 is used for conducting with the ground wire, and the first metal layer 21 is used for conducting with the load, the potential of the load is greater than zero potential and less than the potential of the core wire of the cable.

[0052] Specifically, in the voltage dividing film 20 provided in the present application, Figure 3 , the voltage dividing film 20 comprises a first metal layer 21, an insulating layer 22 and a second metal layer 23, please refer to Figure 1 and Figure 2 , one side of the first metal layer 21 of the flat voltage dividing film 20 faces the insulating sleeve 112 of the cable 110 and is wound on the outside of the insulating sleeve 112 to form a hollow cylindrical voltage dividing film 20, the arc-shaped surfaces of the first arc-shaped shell 11 and the second arc-shaped shell 12 face the voltage dividing film 20 and are at least partially attached to the second metal layer 23 of the voltage dividing film 20, and the arc-shaped shells can maintain the shape of the voltage dividing film 20.

[0053] The voltage dividing film 20 of the cable sleeve 100 has a first metal layer 21, and a ring-shaped insulating sleeve 112 is arranged between the ring-shaped first metal layer 21 and the core wire 111 of the cable 110, so as to form a capacitor structure (a first capacitor), wherein the first metal layer 21 and the core wire 111 serve as two electrodes of the first capacitor, and the insulating sleeve 112 serves as an insulating medium between the two electrodes of the first capacitor.

[0054] Correspondingly, the voltage dividing film 20 can form another capacitor structure (a second capacitor), and the voltage dividing film 20 surrounding the outside of the insulating sleeve 112 is in a hollow cylindrical shape, so that the first metal layer 21, the insulating layer 22 and the second metal layer 23 are all in a hollow cylindrical shape, the first metal layer 21 and the second metal layer 23 serve as two electrodes of the second capacitor, and the insulating layer 22 serves as an insulating medium between the two electrodes of the second capacitor.

[0055] Further, the first metal layer 21 simultaneously serves as one electrode of the first capacitor and the second capacitor, so that the first capacitor and the second capacitor are connected in series, the core wire 111 serves as the other electrode of the first capacitor and is at a high potential, the second metal layer 23 serves as the other electrode of the second capacitor and is at zero potential, the first capacitor and the second capacitor are connected in series between the high potential and the zero potential, the first capacitor forms a high-voltage arm, and the second capacitor forms a low-voltage arm, so as to achieve voltage division of the core wire 111.

[0056] The first metal layer 21 of the cable sleeve 100 is used for conduction with a load, and it can be understood that the load needs to be connected in parallel with one of the first capacitor and the second capacitor, and the first metal layer 21 simultaneously serves as one electrode of the first capacitor and the second capacitor, that is, one of the two poles of the load needs to be connected with the first metal layer 21 for connecting the load.

[0057] It should be pointed out that, Figure 1 The cable 110 in the cable sleeve 100 provided in the above embodiment is a coaxial cable, and the cable sleeve 100 can also achieve voltage division of other types of cables such as multi-core cables and multi-core winding cables.

[0058] In addition, for some types of cables, in addition to being wrapped with an insulating sleeve, a dielectric layer and a metal sheath are arranged outside the insulating sleeve, and the dielectric layer and the metal sheath need to be removed before the cable sleeve 100 is arranged outside the insulating sleeve.

[0059] The application also provides a cable voltage detection device, which comprises a voltmeter and the above-mentioned cable sleeve 100, the cable sleeve 100 is arranged outside the insulating sleeve 112 of the cable 110, and the two poles of the voltmeter are connected with the first metal layer 21 and the second metal layer 23 of the cable sleeve 100, respectively.

[0060] In the power system using cable transmission, there is a rapidly changing impulse voltage caused by external influence, the voltage value of the impulse voltage is high, and the voltage value of the impulse voltage needs to be reduced before being detected by a detection instrument; at the same time, the whole change process of the impulse voltage is usually between nanoseconds or sub-nanoseconds, the sensitivity of resistance voltage division to the impulse voltage is low, and the use of resistance voltage division will affect the impulse voltage, resulting in distorted detection results.

[0061] The cable sleeve 100 of the present application forms a capacitive voltage division with the cable 110 to reduce the voltage of the load, and the capacitive voltage division is more sensitive to rapidly changing voltage and current signals, so that the detection results of the detection instrument are closer to the true value, and is suitable for detecting impulse voltage.

[0062] It should be pointed out that the cable sleeve 100 of the present application can not only be applied to the cable voltage detection device, but also be applied to other devices or systems that need voltage division.

[0063] In one embodiment, the radial sleeve 10 of the cable sleeve 100 is provided with a through hole 14, the cable sleeve 100 comprises a conductive part 30, the conductive part 30 is at least partially located in the through hole 14, one end of the conductive part 30 is used for conducting with the first metal layer 21, and the other end of the conductive part 30 extends out of the sleeve 10 for conducting with the load. One end of the conductive part 30 conducts the first metal layer 21, and the other end extends out of the sleeve 10 to the outside, which facilitates the load to be directly connected with the end of the conductive part 30 located outside the sleeve 10, and then realizes the conduction between the load and the first metal layer 21 on the opposite inner side.

[0064] Please refer to Figure 4 and Figure 5 wherein, Figure 4 schematic diagram of the partial cross section of the voltage division film 20 in the flat state provided in one embodiment of the present application is shown; Figure 5 schematic diagram of the partial cross section of the cable sleeve 100 provided with the cable 110 in one embodiment of the present application is shown.

[0065] In one embodiment, the radial second metal layer 23 and the insulating layer 22 of the cable sleeve 100 are respectively provided with a first avoidance hole 231 and a second avoidance hole 221, the first avoidance hole 231 is communicated between the through hole 14 and the second avoidance hole 221, and the first avoidance hole 231 and the second avoidance hole 221 are used to expose part of the first metal layer 21, so as to facilitate the conduction between the first metal layer 21 and the conductive part 30, and then realize the conduction between the first metal layer 21 and the load.

[0066] In Figure 5In the cable bushing 100 provided, the second metal layer 23 and the insulating layer 22 are respectively provided with a first avoiding hole 231 and a second avoiding hole 221, the first avoiding hole 231 and the second avoiding hole 221 expose part of the first metal layer 21, so that the conductive member 30 can pass through the first avoiding hole 231 and the second avoiding hole 221 to conduct with the first metal layer 21, thereby realizing the conduction of the first metal layer 21 with the load.

[0067] In another embodiment, the second metal layer 23 and the insulating layer 22 along the radial direction of the cable bushing 100 are respectively provided with a first avoiding hole 231 and a second avoiding hole 221, the first avoiding hole 231 and the second avoiding hole 221 along the axial direction of the cable bushing 100 are located outside the sleeve 10, the first avoiding hole 231 and the second avoiding hole 221 are in communication and expose part of the first metal layer 21, the exposed first metal layer 21 is located on the opposite side of the cable bushing 100, which facilitates the conduction of the first metal layer 21 with the load.

[0068] In one embodiment, as shown in Figure 4 The first metal layer 21 includes a first protruding portion 211, the first protruding portion 211 extends towards the direction away from the cable 110, the first protruding portion 211 passes through the first avoiding hole 231 and the second avoiding hole 221, and is used to form at least part of the conductive member 30, so as to facilitate the conduction of the load with the first metal layer 21 on the opposite side.

[0069] In another embodiment, the first protruding portion 211, the first avoiding hole 231 and the second avoiding hole 221 along the axial direction of the cable bushing 100 are located outside the sleeve 10, the first protruding portion 211 extends through the first avoiding hole 231 and the second avoiding hole 221 to the side of the second metal layer 23 away from the cable 110, and the exposed first protruding portion 211 can also facilitate the conduction with the load.

[0070] Please refer to Figure 6 The partial cross-sectional view of the cable bushing 100 provided in another embodiment of the present application is shown in the schematic diagram.

[0071] In some embodiments, the voltage dividing film 20 along the circumferential direction of the cable bushing 100 is formed with at least one splicing seam 24, the splicing seam 24 extends along the axial direction of the cable bushing 100.

[0072] In one of the embodiments, the cable bushing 100 includes a voltage dividing film 20, the voltage dividing film 20 surrounds the outside of the insulating sleeve 112, the two ends of the voltage dividing film 20 are spliced with each other and form a splicing seam 24, the splicing seam 24 extends along the axial direction of the cable bushing.

[0073] In another embodiment, the cable bushing 100 includes a plurality of voltage dividing films 20 arranged along the circumference of the cable bushing 100, and the two ends of two adjacent voltage dividing films 20 are spliced to each other to form a splice joint 24, so that the voltage dividing film 20 has a plurality of splice joints 24 arranged along the circumference of the cable bushing 100, and each splice joint 24 extends along the axial direction of the cable bushing.

[0074] Referring to Figure 7 Fig. 4 is a schematic view of a partial cross section of a cable bushing with a cable according to another embodiment of the present application.

[0075] In one embodiment, as Figure 6 and Figure 7 shown, the through hole 14 communicates with the splice joint 24, and the conductive member 30 passes through the splice joint 24 to be in conductive communication with the first metal layer 21, and the outer side of the conductive member 30 is sleeved with an insulating sheath 32 to separate the conductive member 30 from the second metal layer 23, and the insulating sheath 32 is used to prevent the second metal layer 23 from being in conductive communication with the conductive member 30, thereby avoiding the failure of the capacitive voltage division of the cable bushing 100.

[0076] In one embodiment, the two end faces of the voltage dividing film 20 around the outer side of the insulating sleeve 112 are parallel to each other, so that the cross-sectional area of the splice joint 24 is constant along the radial direction of the cable bushing 100, i.e. Figure 6 The splice joint 24 in the cable bushing 100 provided by the present application is provided to ensure the conductive communication between the conductive member 30 and the first metal layer 21, and the cross section of the conductive member 30 towards one end of the cable 110 is larger to ensure the contact area between the conductive member 30 and the first metal layer 21 and reduce the energy loss.

[0077] In addition, the conductive member 30 includes an insulating section with a smaller cross-sectional area, and the outer side of the insulating section is sleeved with an insulating sheath 32 to separate the conductive member 30 from the second metal layer 23.

[0078] In another embodiment, the two end faces of the voltage dividing film 20 in the flat state are parallel to each other, and the edges of the splice joint 24 formed after being wrapped around the outer side of the insulating sleeve 112 are inclined, i.e. the cross-sectional area of the splice joint 24 gradually increases in the direction away from the cable 110. It can be understood that the splice joint 24 with inclined edges can expose the first metal layer 21, thereby facilitating the conductive communication between the conductive member 30 and the first metal layer 21.

[0079] Referring to Figure 8 Fig. 4 is a schematic view of a partial cross section of a cable bushing with a cable according to another embodiment of the present application.

[0080] In one embodiment, as Figure 8As shown, the cable bushing 100 includes a plurality of conductive pieces 30 and a plurality of insulating sheaths 32, the plurality of conductive pieces 30 are arranged in intervals along the extension direction of the splice joint 24, each conductive piece 30 is in conduction between the first metal layer 21 and the load, and each conductive piece 30 is sleeved with an insulating sheath 32 on the outer side to separate the conductive piece 30 from the second metal layer 23. The plurality of conductive pieces 30 are in conduction between the first metal layer 21 and the load at the same time, which can avoid the cable bushing 100 from failing to work normally due to the failure of a single conductive piece 30, and improve the reliability of the cable bushing 100. The insulating sheath 32 can also prevent the conduction between the adjacent two conductive pieces 30.

[0081] In an embodiment, the cable bushing 100 includes a plurality of voltage division films 20 arranged along the axial direction of the cable bushing 100, the two ends of adjacent two voltage division films 20 are spliced with each other and form a circumferential splice joint, so that the voltage division film 20 has a plurality of circumferential splice joints arranged along the axial direction of the cable bushing 100, and each circumferential splice joint extends along the circumferential direction of the cable bushing 100.

[0082] In an embodiment, the through hole 14 is in communication with the circumferential splice joint, the conductive piece 30 passes through the circumferential splice joint to be in conduction with the first metal layer 21, the outer side of the conductive piece 30 is sleeved with the insulating sheath 32 to separate the conductive piece 30 from the second metal layer 23, and the insulating sheath 32 is used to prevent the second metal layer 23 from being in conduction with the conductive piece 30, thereby avoiding the failure of the capacitive voltage division of the cable bushing 100.

[0083] It can be understood that, along the radial direction of the cable bushing 100, the cross-sectional area of the circumferential splice joint is constant, in order to ensure the conduction between the conductive piece 30 and the first metal layer 21, the cross section of the conductive piece 30 towards one end of the cable 110 is larger, so as to ensure the contact area between the conductive piece 30 and the first metal layer 21 and reduce the energy loss. Similarly, the conductive piece 30 includes an insulating section with a smaller cross-sectional area, and the outer side of the insulating section is sleeved with the insulating sheath 32 to separate the conductive piece 30 from the second metal layer 23.

[0084] In an embodiment, the cable bushing 100 includes a plurality of conductive pieces 30 and a plurality of insulating sheaths 32, the plurality of conductive pieces 30 are arranged in intervals along the extension direction of the circumferential splice joint, each conductive piece 30 is in conduction between the first metal layer 21 and the load, and each conductive piece 30 is sleeved with an insulating sheath 32 on the outer side to separate the conductive piece 30 from the second metal layer 23. The plurality of conductive pieces 30 are in conduction between the first metal layer 21 and the load at the same time, which can avoid the cable bushing 100 from failing to work normally due to the failure of a single conductive piece 30, and improve the reliability of the cable bushing 100. The insulating sheath 32 can also prevent the conduction between the adjacent two conductive pieces 30.

[0085] In an embodiment, as shown in FIG. 6, the cable bushing 100 includes a plurality of conductive pieces 30 and a plurality of insulating sheaths 32, the plurality of conductive pieces 30 are arranged in intervals along the extension direction of the circumferential splice joint, each conductive piece 30 is in conduction between the first metal layer 21 and the load, and each conductive piece 30 is sleeved with an insulating sheath 32 on the outer side to separate the conductive piece 30 from the second metal layer 23. Figure 4As shown, the insulating layer 22 includes a second protruding portion 222 extending towards the second metal layer 23, the second protruding portion 222 is arranged on the outer side of the conductive member 30 to separate the conductive member 30 from the second metal layer 23, preventing the second metal layer 23 from being in conduction with the conductive member 30, and further avoiding the invalidation of the voltage division of the cable gland 100.

[0086] Referring to Figure 9 Fig. 4 shows a cross-sectional view of a cable gland 100 with a cable 110 according to another embodiment of the present application.

[0087] In one embodiment, as Figure 9 shown, the cable gland 100 includes a resistor 31 fixed in the through hole 14, and the resistor 31 is in series with the conductive member 30. The resistor 31 is in series with the conductive member 30 to make the resistor 31 in series with the load, and the resistor 31 can perform resistance voltage division after the voltage division of the two capacitors, to further reduce the voltage of the load.

[0088] In one embodiment, the material of the inner wall of the through hole 14 of the sleeve 10 includes conductive material, and the grounding of the inner wall of the through hole 14 can reduce the external interference on the resistor.

[0089] In one embodiment, the material of the inner wall of the through hole 14 of the sleeve 10 includes conductive material, the resistor 31 is located on the axis of the through hole 14, and the resistor 31 is spaced from the inner wall of the through hole 14 to avoid the conduction between the resistor 31 and the sleeve 10.

[0090] In one embodiment, the resistor 31 is filled with insulating material between the resistor 31 and the inner wall of the through hole 14 to avoid the conduction between the resistor 31 and the sleeve 10.

[0091] In one embodiment, the resistance of the resistor 31 is adjustable. It can be understood that the capacitance of the two capacitors of the cable gland 100 is related to the divider film 20 and the cable 110, that is, the voltage division ratio of the capacitive voltage division is difficult to change, and adjusting the resistance of the resistor 31 can change the voltage of the load to adapt to different loads in different occasions.

[0092] In one embodiment, as Figure 9 shown, the conductive member 30 extends out of one end of the sleeve 10 to form a connector 15, and the connector 15 is used to connect the load.

[0093] In one embodiment, the connector 15 is a BNC connector, and in other embodiments, the connector 15 can also be other types of connectors.

[0094] In an embodiment, the area of the first metal layer 21 and the second metal layer 23 along the thickness direction of the voltage dividing film 20 is different. It can be understood that the capacitance value of the second capacitor is related to the corresponding area of the first metal layer 21 and the second metal layer 23, and changing the area of the first metal layer 21 and the second metal layer 23 can change the capacitance value of the second capacitor, thereby adjusting the voltage dividing ratio.

[0095] It can be understood that for different types of cables and different sizes of voltages, the facing area of the first metal layer 21 and the second metal layer 23, and the thickness and material of the first metal layer 21, the insulating layer 22 and the second metal layer 23 can be changed to change the voltage dividing ratio of the cable sleeve 100, thereby being applicable to more scenarios.

[0096] In an embodiment, the material of the inner circumferential surface of the sleeve 10 includes a conductive material, the second metal layer 23 is conductive with the ground wire through the sleeve 10, the inner circumferential surface of the sleeve 10 is attached to the second metal layer 23 so that the second metal layer 23 is conductive with the sleeve 10, and the sleeve 10 is located on the opposite outer side of the cable sleeve 100. The connection of the ground wire through the sleeve 10 facilitates the conduction of the second metal layer 23 with the ground wire; at the same time, the conductive sleeve 10 of the ground wire can also reduce the external interference received by the cable sleeve 100.

[0097] In an embodiment, the voltage dividing film 20 is at least partially exposed to the outside of the sleeve 10 along the axial direction of the cable sleeve 100, and the exposed area of the second metal layer 23 is used for conduction with the ground wire. The voltage dividing film 20 is at least partially located on the outside of the sleeve 10 so as to facilitate the conduction of the second metal layer 23 with the ground wire, thereby realizing the capacitive voltage division of the cable sleeve 100.

[0098] In an embodiment, the sleeve 10 includes at least two arc-shaped shells arranged along the circumferential direction of the cable sleeve 100, and the two arc-shaped shells adjacent along the circumferential direction of the cable sleeve 100 are fixedly connected. The radius of each arc-shaped shell is less than or equal to the sum of the outer circumferential surface radius of the insulating sleeve 112 and the thickness of the voltage dividing film 20.

[0099] In Figure 1 In the provided cable sleeve 100, the sleeve 10 is divided into a first arc-shaped shell 11 and a second arc-shaped shell 12, which facilitates the installation of the sleeve 10 on the outside of the voltage dividing film 20. The first arc-shaped shell 11 and the second arc-shaped shell 12 are respectively provided with a connecting hole 13 for connecting the first arc-shaped shell 11 and the second arc-shaped shell 12. The radius of the arc-shaped shell is less than the sum of the outer circumferential surface radius of the insulating sleeve 112 and the thickness of the voltage dividing film 20, so that the arc-shaped shell can hold the voltage dividing film 20, and the voltage dividing film 20 can be closely attached to the insulating sleeve 112.

[0100] In one embodiment, the sum of the central angles of the at least two arc-shaped shells is less than 360°, so that a gap is left between the arc-shaped shells along the circumference of the cable sleeve 100 to accommodate part of the partial pressure film 20.

[0101] In one embodiment, the partial pressure film 20 is first wrapped around the outside of the insulating sleeve 112 of the cable 110, and then the sleeve 10 is used to fix the partial pressure film 20, so as to ensure the adhesion of the first metal layer 21 to the outer circumferential surface of the insulating sleeve 112.

[0102] In one embodiment, the second metal layer 23 is coated with a partially conductive adhesive on the side away from the cable 110, so as to achieve the relative fixation of the partial pressure film 20 to the sleeve 10, and also to improve the adhesion of the second metal layer 23 to the inner circumferential surface of the sleeve 10.

[0103] In one embodiment, the cable sleeve 100 includes a resistor and a transmission line, and the resistor and the transmission line are connected in series with the voltmeter. The ratio of the resistance value of the resistor to the wave impedance of the transmission line is in the range of 10-120. The resistor and the voltmeter connected in series can form a resistive voltage divider, further reducing the voltage across the voltmeter, and achieving higher voltage detection.

[0104] In addition, the transmission line is equivalent to an inductor in a rapidly changing signal, and the load effect of the transmission line in the process of detecting the impulse voltage will affect the detection result. Setting the ratio of the resistance value of the resistor to the wave impedance of the transmission line in the range can reduce the influence of the load effect on the detection result of the voltmeter.

[0105] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "exemplary embodiment", "example", "specific example" or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the exemplary description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

Claims

1. A cable sleeve, characterized in that The cable sleeve comprises a sleeve and a voltage division film, the sleeve is sleeved on the outer periphery of the insulating sleeve of the cable and is spaced from the insulating sleeve, the voltage division film is filled between the sleeve and the insulating sleeve, the voltage division film comprises a first metal layer, an insulating layer and a second metal layer arranged in sequence from inside to outside along the radial direction of the cable sleeve, the first metal layer and the second metal layer are at least partially attached to the outer peripheral surface of the insulating sleeve and the inner peripheral surface of the sleeve respectively, the second metal layer is used for conducting with the ground wire, and the first metal layer is used for conducting with the load, the potential of the load is greater than zero potential and less than the potential of the core wire of the cable.

2. The cable sleeve of claim 1, wherein, The sleeve is provided with a through hole along the radial direction of the cable sleeve, the cable sleeve comprises a conductive part, the conductive part is at least partially located in the through hole, one end of the conductive part is used for conducting with the first metal layer, and the other end of the conductive part extends out of the sleeve and is used for conducting with the load.

3. The cable jacket of claim 2, wherein, The second metal layer and the insulating layer are respectively provided with a first avoiding hole and a second avoiding hole penetrating along the radial direction of the cable sleeve, the first avoiding hole is communicated between the through hole and the second avoiding hole, and the first avoiding hole and the second avoiding hole are used for exposing part of the first metal layer to facilitate the conduction between the first metal layer and the conductive part.

4. The cable gland of claim 3, wherein, The first metal layer comprises a first protruding part, the first protruding part extends towards the direction away from the cable, the first protruding part penetrates through the first avoiding hole and the second avoiding hole, and is used for forming at least part of the conductive part.

5. The cable jacket of claim 2, wherein, The voltage division film is formed with at least one splicing joint along the circumferential direction of the cable sleeve, the splicing joint extends along the axial direction of the cable sleeve, wherein: The through hole is communicated with the splicing joint, the conductive part penetrates through the splicing joint to conduct with the first metal layer, and the outer side of the conductive part is sleeved with an insulating sheath to separate the conductive part from the second metal layer.

6. The cable jacket of claim 5, wherein, The cable sleeve comprises a plurality of conductive parts and a plurality of insulating sheaths, a plurality of conductive parts are arranged at intervals along the extension direction of the splicing joint, each conductive part conducts between the first metal layer and the load, and the outer side of each conductive part is sleeved with an insulating sheath to separate the conductive part from the second metal layer.

7. The cable jacket of claim 2, wherein, The insulating layer comprises a second protruding part, the second protruding part extends towards the second metal layer, and the second protruding part is arranged around the outer side of the conductive part to separate the conductive part from the second metal layer.

8. The cable jacket of claim 2, wherein, The cable sleeve comprises a resistor, the resistor is fixed in the through hole, and the resistor is connected in series with the conductive part.

9. A cable sleeve as claimed in any one of claims 1 to 7, characterised in that, The material of the inner peripheral surface of the sleeve comprises a conductive material, the second metal layer conducts with the ground wire through the sleeve; and / or The voltage division film is at least partially exposed to the outside of the sleeve along the axial direction of the cable sleeve, and the exposed area of the second metal layer is used for conducting with the ground wire.

10. A cable voltage detection device, characterized by, The cable sleeve comprises a voltage table and the cable sleeve according to any one of claims 1-9, the cable sleeve is sleeved outside the insulating sleeve of the cable, and the two poles of the voltage table conduct with the first metal layer and the second metal layer of the cable sleeve respectively.

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