A medium voltage cable for photovoltaic power generation

Abstract

The present invention relates to the field of cable technology, specifically to a medium-voltage cable for photovoltaic power generation, which solves the problem that the inner cable core of the medium-voltage cable is in a straight state, and when the cable is subjected to axial force, the cable core will be broken or damaged due to the action of the axial force due to its poor axial elasticity, and the inner cable core of the Central Asian cable is easily bent and damaged or broken when subjected to external pressure. A medium-voltage cable for photovoltaic power generation includes an insulating outer sheath, the inner side of the insulating outer sheath is provided with a pressure-resistant protective sleeve, the inner side of the pressure-resistant protective sleeve is provided with an armored protective sleeve, the inner side of the armored protective sleeve is provided with an insulating shielding protective sleeve, and the inner side of the insulating shielding protective sleeve is interspersed with a plurality of cable cores. The present invention uses a cable core bundling structure to make the cable core bend in a wavy shape, so that the cable core can be extended and stretched after being subjected to axial force, thereby avoiding damage or breakage of the cable core due to the inability to extend axially when subjected to axial force.

Description

Technical Field

[0001] The present invention relates to the technical field of cables, in particular to a medium-voltage cable for photovoltaic power generation. Background Art

[0002] A cable is a conductor that transmits electricity or information from one place to another, made of one or more mutually insulated conductors and an outer insulating protective layer. It is usually made of several or several groups of conductors (at least two in each group) twisted together like a rope. Each group of conductors is insulated from each other and often twisted around a central core. The entire cable is covered with a highly insulating covering. The cable has the characteristics of internal conduction and external insulation.

[0003] Medium voltage cables are power cables with a rated voltage between 1kV-35kV (or 6kV-35kV). They are used for power transmission and distribution at medium voltage levels and are the key link between substations and distribution networks. Medium voltage cables are also commonly used for power transmission in photovoltaic power generation.

[0004] However, the inner core of the medium-voltage cable is in a straight state. When the cable is subjected to axial force, the cable core will break or be damaged due to the poor axial elasticity due to the axial force. Moreover, when the Central Asia cable is subjected to external pressure, the inner core is easy to bend and be damaged or broken. Therefore, it does not meet the existing needs. In this regard, we propose a medium-voltage cable for photovoltaic power generation. Summary of the Invention

[0005] The purpose of the present invention is to provide a medium-voltage cable for photovoltaic power generation, so as to solve the problems proposed in the above-mentioned background technology that the internal cable core of the medium-voltage cable is in a straight state, and when the cable is subjected to axial force, the cable core will break or be damaged due to the action of the axial force due to its poor axial elasticity, and when the Central Asia cable is subjected to external pressure, the internal cable core is easily bent and damaged or broken.

[0006] To achieve the above objectives, the present invention provides the following technical solutions: a medium-voltage cable for photovoltaic power generation, comprising an insulating outer sheath, a pressure-resistant protective sleeve provided on the inner side of the insulating outer sheath, an armored protective sleeve provided on the inner side of the pressure-resistant protective sleeve, an insulating shielding protective sleeve provided on the inner side of the armored protective sleeve, a plurality of cable cores inserted into the inner side of the insulating shielding protective sleeve, sealing filling blocks filled on the inner sides of both ends of the insulating shielding protective sleeve, a cable core bundling structure installed between two of the sealing filling blocks, and ends of the cable cores passing through the sealing filling blocks;

[0007] The cable core bundling structure includes a plurality of first guide rings and a plurality of second guide rings, a rubber connecting strip is fixed between the first guide ring and the plurality of second guide rings, a center adjustment soft rod is inserted axially through the first guide ring and the second guide ring, the first guide ring and the second guide ring are spaced apart from each other, and six supporting short rods distributed in a circular array are fixed to the outer surface of the first guide ring, and a bundling support ring is fixed to the outer side of the six supporting short rods, and a surface of the bundling support ring is penetrated by a plurality of cable core first bundling holes distributed in a circular array around the center of the circle, and a plurality of sliding connecting rods are slidably installed through the interior of the second guide ring, and the number of the sliding connecting rods is consistent with the number of the cable core first bundling holes, and an adjusting ring is fixed to the outer end of the sliding connecting rod, and a cable core second bundling hole is axially penetrated by the adjusting ring, and the cable core passes through the inner side of the cable core second bundling hole and the cable core first bundling hole.

[0008] Preferably, the adjustment ring corresponds one-to-one to the position of the first bunching hole of the cable core, the end of the central adjustment soft rod passes through the sealing filling block, the inner side of the second guide ring is provided with a plurality of storage holes distributed in a circular array around its axis, one end of the sliding connecting rod is slidably inserted into the inner side of the storage hole and points to the axis of the second guide ring, and the end of the sliding connecting rod located on the inner side of the second guide ring is fixed with an adjustment ball head, and the adjustment ball head is hemispherical.

[0009] Preferably, elastic tie ropes are provided on both sides of the outer end of the sliding connecting rod, and the two ends of the elastic tie ropes are fixedly connected to the outer surface of the adjustment ring and the outer surface of the second guide ring respectively.

[0010] Preferably, the outer surface of the central adjustment soft rod is provided with a plurality of adjustment grooves distributed in a circular array, and connecting arc surfaces are provided on both sides of the adjustment grooves.

[0011] Preferably, the pressure-resistant protective sleeve includes a rubber jacket, which is located between the insulating outer skin and the insulating shielding protective sleeve and is completely in contact with the inner surface of the insulating outer skin and the outer surface of the insulating shielding protective sleeve. A plurality of rubber connecting rings are provided on the inner side of the rubber jacket, and the rubber connecting rings are distributed in a linear array along the length direction of the rubber jacket.

[0012] Preferably, a buffer ring and a rigid support ring are provided between every two adjacent rubber connecting rings. The rigid support ring is located inside the buffer ring and its center coincides with the center of the buffer ring. The ends of the buffer ring and the rigid support ring are connected to the rubber connecting ring by adhesive.

[0013] Preferably, a plurality of buffer airbags are provided between the buffer ring and the rigid support ring, and the buffer airbags are distributed in a circular array around the center of the rigid support ring.

[0014] Preferably, the interior of the buffer airbag is hollow and filled with an inert gas, and the buffer airbag is bonded and fixed to the buffer ring and the rigid support ring by adhesive.

[0015] Preferably, a plurality of first buffer springs are fixed to the inner surface of the buffer ring, and a plurality of second buffer springs are fixed to the outer surface of the buffer ring. The number of the first buffer springs and the second buffer springs are the same and are distributed in a circular array around the center of the buffer ring. The first buffer springs and the second buffer springs are both arc-shaped.

[0016] Preferably, rigid T-shaped support blocks are fixed on both sides of the buffer airbag, and the rigid T-shaped support blocks are located between the first buffer elastic sheet and the second buffer elastic sheet.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1. The present invention uses a cable core bundling structure to make the cable core bend in a wave shape, so that the cable core can extend and stretch after being subjected to axial force, thereby avoiding damage or breakage of the cable core due to the inability to extend axially when subjected to axial force;

[0019] 2. The present invention increases the cable's ability to offset, weaken and absorb external pressure through the pressure-resistant protective sleeve, and uses a bunching support ring and an adjustment ring to bunch and support the cable core. At the same time, the bunching support ring and adjustment can prevent the insulating shielding protective sleeve from direct contact with the cable core, thereby preventing the cable core from being damaged, broken or fractured due to bending due to external pressure. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic structural diagram of the present invention as a whole;

[0021] Figure 2 is a schematic cross-sectional view of the cable of the present invention;

[0022] Figure 3 This is a schematic structural diagram of the cable core bundling structure of the present invention;

[0023] Figure 4 for Figure 2 A magnified view of the structure at point A;

[0024] Figure 5 This is a schematic structural diagram of the convergence support ring of the present invention;

[0025] Figure 6 This is a cross-sectional view of the structure of the second guide ring of the present invention;

[0026] Figure 7 This is a structural diagram of the center adjustment soft rod of the present invention;

[0027] Figure 8This is a schematic structural diagram of the compression-resistant protective sleeve of the present invention;

[0028] Figure 9 for Figure 8 A magnified view of the structure at point B.

[0029] In the figure: 1. Insulating outer sheath; 2. Armored protective cover; 3. Insulating shielding protective cover; 4. Cable core bundling structure; 401. Central adjustment soft rod; 402. Bundling support ring; 403. Adjustment ring; 404. First guide ring; 405. Second guide ring; 406. Support short rod; 407. First bundling hole of cable core; 408. Sliding connecting rod; 409. Elastic bundling rope; 410. Second bundling hole of cable core; 411. Adjustment groove; 412. Storage hole; 413. Adjustment ball head; 414. Connecting arc surface; 415. Rubber connecting strip; 5. Compression-resistant protective cover; 501. Rubber jacket; 502. Rubber connecting ring; 503. Buffer ring; 504. Rigid support ring; 505. Buffer airbag; 506. First buffer spring; 507. Second buffer spring; 508. Rigid T-shaped support block; 6. Cable core; 7. Sealing filling block. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0031] like Figure 1 and Figure 2 As shown, a medium-voltage cable for photovoltaic power generation includes an insulating outer sheath 1, a pressure-resistant protective sleeve 5 is provided on the inner side of the insulating outer sheath 1, an armored protective sleeve 2 is provided on the inner side of the pressure-resistant protective sleeve 5, an insulating shielding protective sleeve 3 is provided on the inner side of the armored protective sleeve 2, a plurality of cable cores 6 are inserted into the inner side of the insulating shielding protective sleeve 3, the inner sides of both ends of the insulating shielding protective sleeve 3 are filled with sealing filling blocks 7, a cable core bundling structure 4 is installed between the two sealing filling blocks 7, the ends of the cable cores 6 pass through the sealing filling blocks 7, and the sealing filling blocks 7 are used to seal the ends of the insulating shielding protective sleeve 3 to prevent air or water vapor from entering the cable from the cable ends.

[0032] like Figure 2 、 Figures 5 to 7As shown, the cable core bundling structure 4 includes a plurality of first guide rings 404 and a plurality of second guide rings 405, a rubber connecting strip 415 is fixed between the first guide ring 404 and the plurality of second guide rings 405, a center adjustment soft rod 401 is axially inserted through the first guide ring 404 and the second guide ring 405, the first guide ring 404 and the second guide ring 405 are spaced apart from each other, six supporting short rods 406 distributed in an annular array are fixed to the outer surface of the first guide ring 404, a bundling support ring 402 is fixed to the outside of the six supporting short rods 406, a surface of the bundling support ring 402 is penetrated by a plurality of cable core first bundling holes 407 distributed in a circular array around the center of the circle, and the interior of the second guide ring 405 is penetrated by a sliding installation There are multiple sliding connecting rods 408, the number of which is consistent with the number of the first bunching holes 407 of the cable core, and an adjusting ring 403 is fixed to the outer end of the sliding connecting rod 408. The adjusting ring 403 is axially penetrated by a second bunching hole 410 of the cable core, and the cable core 6 passes through the inner side of the second bunching hole 410 and the first bunching hole 407 of the cable core. The adjusting ring 403 and the bunching support ring 402 are used to guide and support the cable core 6 to avoid entanglement between adjacent cable cores 6, and when the cable is squeezed, the bunching support ring 402 and the adjusting ring 403 isolate the cable core 6 from the insulating shielding protective cover 3, thereby ensuring that external pressure will not directly act on the cable core 6, avoiding breakage or damage of the cable core 6.

[0033] The adjusting ring 403 corresponds to the first bunching hole 407 of the cable core. The end of the center adjusting soft rod 401 passes through the sealing filling block 7. The inner side of the second guide ring 405 is provided with a plurality of receiving holes 412 distributed in a circular array around its axis. One end of the sliding connecting rod 408 is slidably inserted into the inner side of the receiving hole 412 and points to the axis of the second guide ring 405. The end of the sliding connecting rod 408 located on the inner side of the second guide ring 405 is fixed with an adjusting ball head 413. The adjusting ball head 413 is hemispherical. The outer end of the sliding connecting rod 408 is provided with elastic The elastic drawing rope 409 has two ends fixedly connected to the outer surface of the adjusting ring 403 and the outer surface of the second guide ring 405 respectively. The tension of the elastic drawing rope 409 is used to make the adjusting ring 403 and the cable core 6 passing through the adjusting ring 403 approach the second guide ring 405, so that the cable core 6 inserted into the inner side of the insulating shielding protective sleeve 3 is bent into a wavy shape, so that when the cable is subjected to axial force, the cable core 6 can stretch along the axial direction of the cable, ensuring that the cable core 6 will not be broken due to the axial force of the cable.

[0034] The outer surface of the central adjustment soft rod 401 is provided with a plurality of adjustment grooves 411 distributed in a circular array, and connecting arc surfaces 414 are provided on both sides of the adjustment grooves 411. When the central adjustment soft rod 401 is rotated and aligned with the storage hole 412, the adjustment groove 411 is used to store the storage hole 412, thereby ensuring that the adjustment ring 403 drives the cable core 6 toward the second guide ring 405 after being pulled by the elastic binding rope 409, so that the cable core 6 is curved in a wavy shape, and the connecting arc surface 414 makes the end of the adjustment groove 411 contact smoothly with the outer surface of the central adjustment soft rod 401, ensuring that when the central adjustment soft rod 401 is rotated, the storage hole 412 can be separated from the inner side of the adjustment groove 411 along the connecting arc surface 414, thereby changing the position of the adjustment ring 403, so that the axis of the second bundling hole 410 of the cable core coincides with the axis of the first bundling hole 407 of the cable core.

[0035] like Figure 4 、 Figure 8 and Figure 9 As shown, the pressure-resistant protective sleeve 5 includes a rubber jacket 501, which is located between the insulating outer skin 1 and the insulating shielding protective sleeve 3 and is completely fitted with the inner surface of the insulating outer skin 1 and the outer surface of the insulating shielding protective sleeve 3. A plurality of rubber connecting rings 502 are provided on the inner side of the rubber jacket 501. The rubber connecting rings 502 are distributed in a linear array along the length direction of the rubber jacket 501. A buffer ring 503 and a rigid support ring 504 are provided between every two adjacent rubber connecting rings 502. The rigid support ring 504 is located on the inner side of the buffer ring 503 and the center of the circle coincides with the center of the circle of the buffer ring 503. The ends of the buffer ring 503 and the rigid support ring 504 are connected to the rubber connecting ring 502 by adhesive. The rubber connecting ring 502 is used to increase the overall ductility of the pressure-resistant protective sleeve 5 along the length direction, and the buffer ring 503 and the rigid support ring 504 are used to improve the overall pressure resistance of the pressure-resistant protective sleeve 5, thereby protecting the cable core 6.

[0036] A plurality of buffer airbags 505 are provided between the buffer ring 503 and the rigid support ring 504. The buffer airbags 505 are distributed in a circular array around the center of the rigid support ring 504. The interior of the buffer airbags 505 is hollow and filled with inert gas. The buffer airbags 505 are bonded and fixed to the buffer ring 503 and the rigid support ring 504 by adhesive. The buffer airbags 505 prevent the buffer ring 503 from approaching the buffer ring 503 when subjected to external pressure, thereby weakening and offsetting the external pressure, reducing the pressure received by the rigid support ring 504, and thus reducing the probability of deformation of the rigid support ring 504.

[0037] The inner surface of the buffer ring 503 is fixed with a plurality of first buffer springs 506, and the outer surface of the buffer ring 503 is fixed with a plurality of second buffer springs 507. The number of the first buffer springs 506 and the second buffer springs 507 is the same and they are distributed in a circular array around the center of the buffer ring 503. The first buffer springs 506 and the second buffer springs 507 are both arc-shaped. A rigid T-shaped support block 508 is fixed on both sides of the buffer airbag 505. The rigid T-shaped support block 508 is located between the first buffer spring 506 and the second buffer spring 507. The impact spring piece 507 increases the elasticity between the buffer ring 503 and the rigid support ring 504, thereby improving the overall pressure resistance of the pressure-resistant protective sleeve 5. After the buffer airbag 505 is deformed under pressure, the rigid T-shaped support block 508 enters between the first buffer spring piece 506 and the second buffer spring piece 507 and contacts the first buffer spring piece 506 and the second buffer spring piece 507. After the rigid T-shaped support block 508 is released from the first buffer spring piece 506 and the second buffer spring piece 507, it prevents the first buffer spring piece 506 and the second buffer spring piece 507 from approaching each other, thereby resisting external pressure.

[0038] Working principle: First, rotate the center adjustment soft rod 401. When the center adjustment soft rod 401 rotates, the adjustment ball head 413 located on the inner side of the adjustment groove 411 is squeezed, so that the adjustment ball head 413 is separated from the inner side of the adjustment groove 411 along the connecting arc surface 414. At this time, the adjustment ball head 413 enters the inner side of the storage hole 412, and the sliding connecting rod 408 extends from the inside of the second guide ring 405 and stretches the elastic tightening rope 409. After the adjustment ball head 413 is completely immersed in the inner side of the storage hole 412, the axis of the adjustment ring 403 coincides with the axis of the first tightening hole 407 of the cable core. At this time, the staff passes the cable core 6 through the inner side of the second tightening hole 410 and the first tightening hole 407 of the cable core. After the cable core 6 is installed, the center adjustment soft rod 4 01 is rotated so that the adjustment slot 411 is realigned with the adjustment ball head 413. At this time, the elastic tightening rope 409 elastically recovers and drives the adjustment ring 403 and the sliding connecting rod 408 to recover. After the adjustment ring 403 recovers, the portion of the cable core 6 passing through the second tightening hole 410 of the cable core is close to the central adjustment soft rod 401. At this time, the cable core 6 is curved in a wavy shape. Then, the tightening support ring 402 and the adjustment ring 403 of the cable core tightening structure 4 with the cable core 6 are installed on the inner side of the insulating shielding protective sleeve 3, and the sealing filling block 7 is used to seal the two ends of the insulating shielding protective sleeve 3. Then, the insulating shielding protective sleeve 3, the armored protective sleeve 2, the pressure-resistant protective sleeve 5, and the insulating outer sheath 1 are installed on the outer side of the insulating shielding protective sleeve 3 to complete the assembly of the cable.

[0039] When the cable is subjected to axial tension, the cable will stretch along the length direction due to the axial tension. At this time, the cable core 6 inserted into the inner side of the insulating shielding protective sleeve 3 is bent in a wavy shape due to the adjusting ring 403 and the tightening support ring 402. When the cable is subjected to axial force, the cable core 6 gradually tends to be a straight line from the wavy state due to the axial tension. At this time, the adjusting ring 403 drives the sliding connecting rod 408 to slide out of the second guide ring 405, and the elastic tightening rope 409 is stretched. During this process, the cable core 6 can be extended along the length direction of the cable, thereby ensuring that when the cable is subjected to axial force, the cable core 6 offsets the axial tension by extending along the length direction of the cable, thereby avoiding damage or breakage of the cable core 6 due to the axial force.

[0040] When the outside of the cable is under pressure, the insulating outer sheath 1 transfers the pressure to the rubber jacket 501 and the buffer ring 503. After the buffer ring 503 is under pressure, it bends and deforms toward the rigid support ring 504, and the rigid support ring 504 drives the first buffer spring 506 to approach the second buffer spring 507. At the same time, the buffer airbag 505 is squeezed and deformed. After the deformation, the end portion of the buffer airbag 505 moves toward the first buffer spring 506 and the second buffer spring 507, so that the rigid T-shaped support block 508 enters between the first buffer spring 506 and the second buffer spring 507. At this time, the first buffer spring 506 squeezes the rigid T-shaped support block 508 onto the second buffer spring 507. Since the rigid T-shaped support block 508 prevents the first buffer spring 506 and the second buffer spring 507 from contacting each other, the first buffer spring 506 and the second buffer spring 507 are elastically deformed at this time, and the external pressure is offset and weakened by the elastic deformation of the buffer airbag 505, the first buffer spring 506, and the second buffer spring 507. At the same time, because the cable core 6 is supported by the adjusting ring 403 and the converging support ring 402, the external pressure will eventually only act on the converging support ring 402 and the adjusting ring 403, and the cable core 6 will not be directly affected by the external pressure, thereby avoiding the external pressure causing the cable core 6 to bend and cause the cable core 6 to be damaged or broken.

[0041] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims, not the foregoing description, and all variations within the meaning and range of equivalents of the claims are intended to be included therein. Any reference sign in a claim should not be construed as limiting the claim to which it relates.

Claims

1. A medium voltage cable for photovoltaic power generation, comprising an insulating outer sheath (1), characterized in that: The inner side of the insulating outer sheath (1) is provided with a pressure-resistant protective sleeve (5), the inner side of the pressure-resistant protective sleeve (5) is provided with an armored protective sleeve (2), the inner side of the armored protective sleeve (2) is provided with an insulating shielding protective sleeve (3), the inner side of the insulating shielding protective sleeve (3) is interspersed with a plurality of cable cores (6), the inner sides of both ends of the insulating shielding protective sleeve (3) are filled with sealing filling blocks (7), a cable core bundling structure (4) is installed between the two sealing filling blocks (7), and the ends of the cable cores (6) pass through the sealing filling blocks (7); The cable core bundling structure (4) comprises a plurality of first guide rings (404) and a plurality of second guide rings (405), a rubber connecting strip (415) is fixed between the first guide rings (404) and the plurality of second guide rings (405), a central adjustment soft rod (401) is inserted axially through the first guide rings (404) and the second guide rings (405), the first guide rings (404) and the second guide rings (405) are spaced apart from each other, six supporting short rods (406) distributed in an annular array are fixed on the outer surface of the first guide ring (404), and a bundling support ring (402) is fixed on the outer side of the six supporting short rods (406). ), the surface of the bunching support ring (402) is penetrated by a plurality of first bunching holes (407) of the cable core distributed in a circular array around the center of the circle, the interior of the second guide ring (405) is penetrated by a plurality of sliding connecting rods (408) slidably installed, the number of the sliding connecting rods (408) is consistent with the number of the first bunching holes (407) of the cable core, and an adjusting ring (403) is fixed to the outer end of the sliding connecting rod (408), the axial direction of the adjusting ring (403) is penetrated by a second bunching hole (410) of the cable core, and the cable core (6) passes through the inner side of the second bunching hole (410) of the cable core and the first bunching hole (407) of the cable core.

2. A medium voltage cable for photovoltaic power generation according to claim 1, characterized in that: The adjustment ring (403) corresponds to the position of the first bundle hole (407) of the cable core one by one, the end of the central adjustment soft rod (401) passes through the sealing filling block (7), the inner side of the second guide ring (405) is provided with a plurality of receiving holes (412) distributed in a circular array around its axis, one end of the sliding connecting rod (408) is slidably inserted into the inner side of the receiving hole (412) and points to the axis of the second guide ring (405), and the end of the sliding connecting rod (408) located on the inner side of the second guide ring (405) is fixed with an adjustment ball head (413), and the adjustment ball head (413) is hemispherical.

3. A medium voltage cable for photovoltaic power generation according to claim 2, characterized in that: Elastic drawstrings (409) are provided on both sides of the outer end of the sliding connecting rod (408), and the two ends of the elastic drawstrings (409) are fixedly connected to the outer surface of the adjustment ring (403) and the outer surface of the second guide ring (405), respectively.

4. A medium voltage cable for photovoltaic power generation according to claim 3, characterized in that: The outer surface of the central adjustment soft rod (401) is provided with a plurality of adjustment grooves (411) distributed in a circular array, and both sides of the adjustment groove (411) are provided with connecting arc surfaces (414).

5. The medium voltage cable for photovoltaic power generation according to claim 1, characterized in that: The pressure-resistant protective sleeve (5) comprises a rubber outer sleeve (501), the rubber outer sleeve (501) being located between the insulating outer skin (1) and the insulating shielding protective sleeve (3) and being completely in contact with the inner surface of the insulating outer skin (1) and the outer surface of the insulating shielding protective sleeve (3), and a plurality of rubber connecting rings (502) being provided on the inner side of the rubber outer sleeve (501), the rubber connecting rings (502) being distributed in a linear array along the length direction of the rubber outer sleeve (501).

6. A medium voltage cable for photovoltaic power generation according to claim 5, characterized in that: A buffer ring (503) and a rigid support ring (504) are provided between every two adjacent rubber connecting rings (502); the rigid support ring (504) is located inside the buffer ring (503) and its center coincides with the center of the buffer ring (503); and the ends of the buffer ring (503) and the rigid support ring (504) are connected to the rubber connecting ring (502) by adhesive.

7. A medium voltage cable for photovoltaic power generation according to claim 6, characterized in that: A plurality of buffer airbags (505) are provided between the buffer ring (503) and the rigid support ring (504), and the buffer airbags (505) are distributed in a circular array around the center of the rigid support ring (504).

8. A medium voltage cable for photovoltaic power generation according to claim 7, characterized in that: The interior of the buffer airbag (505) is hollow and filled with inert gas, and the buffer airbag (505) is bonded and fixed to the buffer ring (503) and the rigid support ring (504) by adhesive.

9. A medium voltage cable for photovoltaic power generation according to claim 8, characterized in that: A plurality of first buffer springs (506) are fixed to the inner surface of the buffer ring (503), and a plurality of second buffer springs (507) are fixed to the outer surface of the buffer ring (503). The number of the first buffer springs (506) and the second buffer springs (507) are the same and are distributed in a circular array around the center of the buffer ring (503). The first buffer springs (506) and the second buffer springs (507) are both arc-shaped.

10. A medium voltage cable for photovoltaic power generation according to claim 9, characterized in that: Rigid T-shaped support blocks (508) are fixed on both sides of the buffer airbag (505), and the rigid T-shaped support block (508) is located between the first buffer spring sheet (506) and the second buffer spring sheet (507).

Images