CN223427274U - Shielding type medium-voltage insulation power cable - Google Patents

Abstract

The utility model discloses a shielded medium-voltage insulated power cable, comprising a cable core; the cable core is composed of two groups of mutually twisted wire cores, each group of the wire cores is composed of a conductor, a conductor shielding layer and a conductor insulation layer; the outside of the cable core is wrapped with an insulating shielding layer, the insulating shielding layer is composed of a semi-conductive layer, a reinforcing layer and a protective layer; the outside of the insulating shielding layer is provided with a metal shielding layer, the metal shielding layer is composed of an anti-interference layer, an alloy layer and a braided layer, and the present solution solves the problem of poor shielding effect of power cables.

Description

Shielding type medium-voltage insulation power cable

Technical Field

The utility model relates to the technical field of power cables, in particular to a shielding type medium-voltage insulating power cable.

Background

Medium voltage insulated power cables are conductors specially designed for transporting medium voltage power and energy, play a vital role in power systems, medium voltage cables generally refer to cables rated at voltages between 1kV and 35kV, these cables are mainly used in power systems for distribution of power grids, urban power supply and power transmission and distribution systems, medium voltage cables are designed with special insulating materials and structures, and can withstand power transmission and operation in high temperature environments, and can generally operate in high temperature environments of 70 ℃ to 150 ℃ for a long time.

For example, chinese issued patent of publication No. CN214588181U, a medium voltage insulated power cable, including a central air pipe, a plurality of insulating sleeves are fixedly connected with each other, wherein the outer pipe wall of the central air pipe is uniformly and annularly equidistant, a cable core conductor is arranged in each insulating sleeve, an anti-interference shielding layer is fixedly sleeved on the outer arc-shaped side wall of each insulating sleeve, an inner sheath is fixedly sleeved on the outer annular side wall of each anti-interference shielding layer, a plurality of buffer strips are fixedly connected with each outer annular side wall of each inner sheath, cylindrical buffer air cavities are formed in each buffer strip, and outer sheaths are fixedly sleeved on the outer arc-shaped side walls of each buffer strip.

When the prior art is actually used, the currents in the cable and the currents in the surrounding wires may affect each other, so that waveform distortion and nonlinear change of voltage of the current are caused, and normal current waveform and voltage stability in the cable are interfered, so that the prior requirements are not met, and a shielding medium-voltage insulating power cable is provided.

Disclosure of utility model

The utility model aims to provide a shielding type medium-voltage insulating power cable, which is used for solving the problem that the shielding effect of the power cable in the background technology is poor.

The shielding type medium voltage insulation power cable comprises a cable core, wherein the cable core consists of two groups of mutually twisted wire cores, each group of wire cores consists of a conductor, a conductor shielding layer and a conductor insulation layer, the insulation shielding layer is wrapped outside the cable core and consists of a semiconductive layer, a reinforcing layer and a protective layer, a metal shielding layer is arranged outside the insulation shielding layer, and the metal shielding layer consists of an anti-interference layer, an alloy layer and a weaving layer.

Preferably, the conductor is twisted together into a bundle by a plurality of aluminum alloy monofilaments, the conductor shielding layer is extruded on the outer wall of the conductor, and the conductor insulating layer is extruded on the outer wall of the conductor shielding layer.

Preferably, the semi-conductive layer is wrapped outside the cable core through an extrusion device, the reinforcing layer is fixed on the outer wall of the semi-conductive layer through a high polymer binder, and the protective layer is wrapped on the outer wall of the reinforcing layer through the extrusion device.

Preferably, the anti-interference layer is spirally wound outside the insulating shielding layer, the alloy layer is spirally wound on the outer wall of the anti-interference layer, and the woven layer is wrapped on the outer wall of the alloy layer in a net shape.

Preferably, a filling layer is arranged at the gap between the cable core and the cable core, and the filling layer adopts carbon black powder.

Preferably, an outer sheath is arranged outside the metal shielding layer, and the outer sheath is fixed with the metal shielding layer by adopting an extrusion process.

Preferably, the thickness of the insulating shielding layer and the thickness of the metal shielding layer are equal.

Compared with the prior art, the utility model has the beneficial effects that:

1. According to the utility model, the insulating shielding layer is arranged, the electric field distribution of the cable can be effectively improved through the optimal design of the multilayer structure, the partial discharge phenomenon is reduced, the electric performance and the safety of the cable are improved, the electric field distribution of the cable can be effectively improved through the composite insulating shielding layer, the partial discharge phenomenon is reduced, the electric performance and the safety of the cable are improved, and the composite insulating shielding layer has better mechanical strength and stress resistance and can bear larger external impact and bending deformation due to the design of the multilayer structure.

2. The composite metal shielding layer is provided with the metal shielding layer, so that the composite metal shielding layer can provide an omnibearing and multilayer electromagnetic shielding effect, effectively inhibit the influence of external electromagnetic interference on internal signals of the cable, and the combination of the inner copper strip, the middle corrosion-resistant alloy layer and the outer high-strength woven net ensures that the integral metal shielding layer has extremely high mechanical strength, can bear larger external pressure and impact, and the corrosion-resistant alloy layer of the middle layer can resist chemical corrosion and oxidation in various severe environments, so that the stability and reliability of the cable in a long-term use process are ensured.

3. According to the utility model, in the design of the wire cores, the spiral winding design of the two groups of wire cores enables the cable to bear larger current under the same outer diameter. The mechanical properties and the stress resistance of the cable are also improved due to the close contact and mutual support between the conductors, allowing a higher current carrying capacity, while the carbon black filling at the gap does not directly constitute the insulating layer, it is able to co-act with the insulating layer, improving the overall insulating properties of the cable. The conductivity of carbon black helps to provide a degree of short-circuit protection when the insulating layer is damaged, reducing the occurrence of electrical accidents.

Drawings

FIG. 1 is a perspective view of the present utility model;

FIG. 2 is a cross-sectional structural view of the present utility model;

FIG. 3 is a schematic view of an insulation shielding layer structure of the present utility model;

Fig. 4 is a schematic view of a metal shielding layer structure of the present utility model.

In the figure, 1, a wire core, 11, a conductor, 12, a conductor shielding layer, 13, a conductor insulating layer, 2, an insulating shielding layer, 21, a semi-conductive layer, 22, a reinforcing layer, 23, a protective layer, 3, a metal shielding layer, 31, an anti-interference layer, 32, an alloy layer, 33, a weaving layer, 4, an outer sheath and 5, and a filling layer.

Detailed Description

The following description of the embodiments of the present utility model will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present utility model, but not all embodiments.

Referring to fig. 1-4, an embodiment of a shielded medium voltage insulated power cable provided by the utility model comprises a cable core, wherein the cable core consists of two groups of mutually twisted wire cores (1), each group of wire cores (1) consists of a conductor (11), a conductor shielding layer (12) and a conductor insulating layer (13), an insulating shielding layer (2) is wrapped outside the cable core, the insulating shielding layer (2) consists of a semiconductive layer (21), a reinforcing layer (22) and a protective layer (23), a metal shielding layer (3) is arranged outside the insulating shielding layer (2), the metal shielding layer (3) consists of an anti-interference layer (31), an alloy layer (32) and a braiding layer (33), and the thicknesses of the insulating shielding layer (2) and the metal shielding layer (3) are equal.

Referring to fig. 2, a conductor 11 is twisted into a bundle by a plurality of aluminum alloy monofilaments, a conductor shielding layer 12 is extruded on the outer wall of the conductor 11, a conductor insulating layer 13 is extruded on the outer wall of the conductor shielding layer 12, the conductor 11 is the aluminum alloy monofilaments so as to reduce resistance and improve power transmission efficiency, the bundle is twisted by a plurality of filaments, and the bundle is compressed by a special die so as to improve compression coefficient, thereby enhancing mechanical performance and current-carrying capacity of a cable, and the conductor shielding layer 12 is made of semiconductive rubber with good conductivity and flexibility and is very suitable for being used as a semiconductive layer of the cable. The electric field distribution of the cable can be effectively improved, the partial discharge phenomenon is reduced, the electrical performance and the safety of the cable are improved, and the insulating layer 13 is crosslinked polyethylene so as to improve the insulating strength, the heat resistance and the mechanical performance.

Referring to fig. 3, the semiconductive layer 21 is wrapped outside the cable core by an extrusion device, the reinforcing layer 22 is fixed on the outer wall of the semiconductive layer 21 by a polymer binder, the protective layer 23 is wrapped on the outer wall of the reinforcing layer 22 by the extrusion device, the semiconductive layer 21 is made of silicone rubber, has high conductivity, can be tightly attached to the surface of a conductor to form a smooth equipotential layer, effectively eliminates charge accumulation on the surface of the conductor, improves electric field distribution, and reduces partial discharge phenomenon. The reinforcing layer 22 is nano alumina, so that the nano alumina has excellent insulating property, and the heat resistance, the mechanical strength and the ageing resistance of the material are improved through the reinforcing effect of nano particles. The protective layer 23 is a thermoplastic elastomer, has good flexibility and elasticity, can be closely attached to other layers of the cable, and provides additional mechanical protection. Meanwhile, the semi-conductive performance of the cable is beneficial to further balancing the electric field distribution inside the cable and improving the electrical safety.

Referring to fig. 4, the anti-interference layer 31 is spirally wound on the outside of the insulating shielding layer 2, the alloy layer 32 is spirally wound on the outer wall of the anti-interference layer 31, the braid layer 33 is wrapped on the outer wall of the alloy layer 32 in a net shape, the anti-interference layer 31 is an electrolytic copper strip, and can effectively transmit current and shield electromagnetic interference to provide a reliable grounding path for the cable, the alloy layer 32 is a nickel alloy, and can resist chemical corrosion and oxidation in the external environment, protect the inner copper strip from damage, and prolong the service life of the cable. The braid 33 is braided by aluminum-magnesium alloy wires, has extremely high mechanical strength, can resist external physical impact and extrusion, and can provide wider electromagnetic shielding effect through dense braiding grids. In addition, the design of the woven net also has good flexibility and workability, and is convenient for bending, installing and maintaining the cable.

Referring to fig. 2, a filling layer 5 is disposed at a gap between the cable core and the cable core 1, and the filling layer 5 is made of carbon black powder, has a highly crystalline carbon characteristic, and has good conductivity. In cable manufacture, carbon black is often used as a conductive filler added to a polymeric material to improve its conductive properties. Such carbon black-added composites are often used to make semiconductive layers for cables.

Referring to fig. 1 and 2, an outer sheath 4 is arranged outside the metal shielding layer 3, the outer sheath 4 is fixed with the metal shielding layer 3 by adopting an extrusion process, the outer sheath 4 adopts flame-retardant, cold-resistant and heat-resistant polyvinyl chloride, the PVC sheath material has good flexibility and firmness, can protect cables or wires from external physical damage, has certain fireproof and oil-proof performances, and can slow down fire spreading under certain conditions and resist erosion of oil substances to a certain extent although the PVC is not completely flame-retardant.

It will be evident to those skilled in the art that the utility model is not limited to the details of the foregoing illustrative embodiments, and that the present utility model may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, the scope of the utility model being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.

Claims (7)

1. A shielded medium-voltage insulated power cable, comprising a cable core; characterized in that: the cable core is composed of two groups of mutually twisted cores (1), each group of the cores (1) is composed of a conductor (11), a conductor shielding layer (12) and a conductor insulation layer (13), the outside of the cable core is wrapped with an insulating shielding layer (2), the insulating shielding layer (2) is composed of a semi-conductive layer (21), a reinforcement layer (22) and a protective layer (23), and a metal shielding layer (3) is provided on the outside of the insulating shielding layer (2), the metal shielding layer (3) is composed of an anti-interference layer (31), an alloy layer (32) and a braided layer (33). 2. A shielded medium-voltage insulated power cable according to claim 1, characterized in that: the conductor (11) is composed of multiple aluminum alloy monofilaments twisted together into a bundle, the conductor shielding layer (12) is extruded on the outer wall of the conductor (11), and the conductor insulation layer (13) is extruded on the outer wall of the conductor shielding layer (12). 3. A shielded medium voltage insulated power cable according to claim 1, characterized in that: the semi-conductive layer (21) is wrapped around the outside of the cable core by an extrusion device, the reinforcing layer (22) is fixed to the outer wall of the semi-conductive layer (21) by a polymer adhesive, and the protective layer (23) is wrapped around the outer wall of the reinforcing layer (22) by an extrusion device. 4. A shielded medium-voltage insulated power cable according to claim 1, characterized in that: the anti-interference layer (31) is spirally wound on the outside of the insulating shielding layer (2), the alloy layer (32) is spirally wound on the outer wall of the anti-interference layer (31), and the braided layer (33) is mesh-wrapped on the outer wall of the alloy layer (32). 5. A shielded medium voltage insulated power cable according to claim 1, characterized in that a filling layer (5) is provided at the gap between the cable core and the wire core (1), and the filling layer (5) is made of carbon black powder. 6. A shielded medium voltage insulated power cable according to claim 1, characterized in that an outer sheath (4) is provided outside the metal shielding layer (3), and the outer sheath (4) is fixed to the metal shielding layer (3) by an extrusion process. 7. A shielded medium voltage insulated power cable according to claim 1, characterized in that the thickness of the insulating shielding layer (2) and the metal shielding layer (3) are equal.