Signal compensation instrument cable for intelligent substation

Abstract

A signal compensation instrument cable for an intelligent substation is characterized by comprising four conductor core wires, a cross-shaped framework, an outer shielding layer and an outer sheath, wherein every two conductor core wires are twisted to form a cable core; the cable meets the basic performance requirements of a novel intelligent large-scale transformer station on the instrument cable, also has the characteristics of environmental protection, flame retardation, remote intelligent control and the like, and solves the problems of signal interference, overhigh induced voltage, overlarge shielding inhibition coefficient, unstable cable working capacitance and the like of the intelligent transformer station in a 220kV strong magnetic field environment on the instrument cable. The popularization and application values are realized.

Description

Technical Field

[0001] This utility model relates to the field of cable technology, and in particular to a signal compensation instrument cable for intelligent substations. Background Technology

[0002] As the future direction of power grid development, smart grids permeate all aspects of power generation, transmission, transformation, distribution, consumption, dispatching, and communication. Among these aspects, smart substations are undoubtedly the most crucial link. Evolved from digital substations, smart substations have become increasingly sophisticated over the years. Compared to other aspects, smart substations have reached the conditions for large-scale promotion.

[0003] Intelligent substations are mainly composed of equipment and system layers. The biggest difference between them and traditional substations lies in three aspects: intelligent primary equipment, condition-based equipment maintenance, and networked secondary equipment. After 2021, all newly built substations will be constructed in accordance with the technical standards for intelligent substations, with a focus on the intelligent transformation of hub and central substations.

[0004] To meet the needs of smart substations, the original instruments have undergone structural optimization and improvement. This is because new intelligent large-scale substations place the following higher requirements on instrument cables, beyond simply meeting basic performance requirements:

[0005] 1. Higher requirements are placed on the performance of low-smoke halogen-free bundled combustion;

[0006] 2. Light transmittance must be no less than 60%;

[0007] 3. Under a 220kV ultra-high voltage strong electromagnetic field environment, the induced voltage of the instrument cable shall not exceed 16V;

[0008] 4. The maximum cable shielding suppression coefficient shall not exceed 0.01;

[0009] 5. The capacitance imbalance between the shielded cable and ground should not exceed 400pF for a length of 250 meters and a frequency of 1kHz. For lengths less than 250m, the measured value should be corrected as follows: multiply the measured value by 250 / L, where L is the length of the test cable (m). For lengths less than 100m, calculate as 100m. The maximum working capacitance should not exceed 120pF / m (previously accepted as 150pF / m). Summary of the Invention

[0010] This utility model addresses the problems mentioned in the background art by providing a signal compensation instrument cable for intelligent substations. It features environmental protection, flame retardancy, and remote intelligent control capabilities, and solves problems such as signal interference from strong magnetic fields, excessively high induced voltage, excessively large shielding suppression coefficient, and unstable cable working capacitance.

[0011] To achieve the above objectives, the present invention adopts the following technical solution:

[0012] A signal compensation instrument cable for intelligent substations, characterized by comprising four conductor cores twisted in pairs, a cross-shaped skeleton, an outer shielding layer, and an outer sheath.

[0013] Each conductor core includes two solid copper conductors and a core shielding layer, and each conductor is provided with a high molecular weight polyethylene insulation layer.

[0014] The core wire shielding layer is a thin strip made of rolled aluminum metal, which is wrapped around two conductors with insulating layers to form a conductor core wire, in order to prevent signal interference between the conductor core wires.

[0015] The cross-shaped skeleton is a filler wire with a cross-shaped cross section. The cross-shaped skeleton is set at the center of the cable core and serves as the central axis for the cable core to be twisted. Four grooves are formed on the cross-shaped skeleton, and each conductor core wire is placed in the groove. The four protruding ends of the cross-shaped skeleton are equidistant from the center point and are greater than or equal to the maximum diameter of the conductor core wire. This can provide a certain support for the outer shielding layer, prevent the instrument cable core from deforming, and keep the secondary parameters of the line unchanged.

[0016] The outer shielding layer is a copper strip that overlaps and wraps around the cable core with a cross skeleton. It is used to prevent external strong electromagnetic fields from causing signal interference to the cable core, thereby effectively reducing the induced voltage of the line.

[0017] The outer sheath is made of low-smoke, halogen-free, flame-retardant polyolefin polymer material, which covers the outer shielding layer.

[0018] A further option is that the conductor specification is 0.5-1.5mm. 2 This is to accommodate the needs of devices with different power levels.

[0019] A further solution is to improve the shielding effect between the conductor cores by having a core shielding layer thickness of 0.035mm, which is overlapped and wrapped around two conductors with insulation layers, requiring an overlap rate of 20% or more.

[0020] A further solution is to fill the gaps between the cross skeleton and the conductor core wire in each groove of the cross skeleton with cotton yarn filler to ensure the structural stability of the conductor core wire.

[0021] A further solution is to improve the shielding effect against strong external magnetic fields, wherein the outer shielding layer has a thickness of 0.05 mm, is wrapped flat, and has an overlap rate of ≥25%.

[0022] The beneficial effects of this utility model are: while meeting the basic performance requirements of instrument cables for new intelligent large-scale substations, it also has the characteristics of environmental protection, flame retardancy, and remote intelligent control. Furthermore, it solves the problems of signal interference, excessively high induced voltage, excessively large shielding suppression coefficient, and unstable working capacitance of instrument cables in the 220kV strong magnetic field environment of intelligent substations, and has the value for promotion and application. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of an embodiment of the present utility model. Detailed Implementation

[0024] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Example

[0025] like Figure 1 As shown, a signal compensation instrument cable for a smart substation includes four conductor cores twisted in pairs, a cross-shaped frame 5, an outer shielding layer 6, and an outer sheath 7.

[0026] Each conductor core includes two solid copper conductors 1 and a core shielding layer 3, and each conductor is provided with a high molecular weight polyethylene insulation layer 2.

[0027] The core wire shielding layer 3 is a thin strip made of rolled aluminum metal, which is wrapped around two conductors 1 with insulation layer 2 to form a conductor core wire, in order to prevent signal interference between conductor core wires.

[0028] The cross-shaped skeleton 5 is a filler wire with a cross-shaped cross section. The cross-shaped skeleton is set at the center of the cable core and serves as the central axis for the cable core to be twisted. Four wire grooves are formed on the cross-shaped skeleton 5, and each conductor core wire is placed in the wire groove. The four protruding ends of the cross-shaped skeleton 5 are equidistant from the center point and are greater than or equal to the maximum diameter of the conductor core wire. This can provide a certain support for the outer shielding layer 6, prevent the instrument cable core from deforming, and keep the secondary parameters of the line unchanged.

[0029] The outer shielding layer 6 is a copper strip that overlaps and wraps around the cable core with the cross skeleton 5. It is used to prevent external strong electromagnetic fields from causing signal interference to the cable core, thereby effectively reducing the induced voltage of the line.

[0030] The outer sheath 7 is made of low-smoke, halogen-free, flame-retardant polyolefin polymer material and is wrapped around the outer shielding layer 6.

[0031] The conductor 1 has a specification of 0.5-1.5 mm2 to adapt to the needs of different power devices.

[0032] To improve the shielding effect between conductor cores, the core shielding layer 3 is 0.035mm thick and is wrapped around the two conductors 1 with insulation layer 2, with a wrapping overlap rate of ≥20%.

[0033] The gaps between the cross skeleton 5 and the conductor core wire in each groove of the cross skeleton 5 are filled with cotton yarn filler 4 to ensure the structural stability of the conductor core wire.

[0034] To better shield against strong external magnetic fields, the outer shielding layer 6 has a thickness of 0.05 mm, is wrapped smoothly, and has an overlap rate of ≥25%.

Claims

1. A signal-compensated instrument cable for a smart substation, characterized by It comprises four pairs of twisted conductor core, cross skeleton, outer shield layer and outer sheath; Each of the conductor core comprises two solid copper conductors and a core shield layer, and each of the conductors is provided with a high molecular polyethylene insulation layer; The core shield layer is a thin strip of aluminum rolled into a band, which is wrapped around the two conductors with insulation layers to form a conductor core, preventing signal interference between the conductor cores. The cross skeleton is a cross-section filled wire, which is arranged at the center of the cable core as the center axis of the cable core, and four wire slots are formed on the cross skeleton, each of the conductor cores is arranged in the wire slot, and the four protruding ends of the cross skeleton are the same distance from the center point and greater than or equal to the maximum diameter of the conductor core, which can support the outer shield layer and prevent the deformation of the cable core and the change of the secondary parameters of the line. The outer shield layer is a layer of copper band wrapped around the cable core with the cross skeleton, which prevents external strong electromagnetic field from interfering with the cable core and effectively reduces the line induced voltage. The outer sheath is a low-smoke halogen-free flame-retardant polyolefin polymer material wrapped outside the outer shield layer.

2. A signal compensating instrument cable for a smart substation as claimed in claim 1, characterized in that The conductor gauge is 0.5-1.5mm 2 .

3. A signal compensating instrument cable for a smart substation according to claim 1 or 2, characterized in that The thickness of the core shield layer is 0.035mm, which is wrapped around the two conductors with insulation layers, and the overlapping rate is greater than or equal to 20%.

4. A signal compensating instrument cable for a smart substation according to claim 1 or 2, characterized in that The space between the cross skeleton and the conductor core in each wire slot of the cross skeleton is filled with a cotton yarn filling body.

5. A signal compensating instrument cable for a smart substation as defined in claim 3, characterized in that The space between the cross skeleton and the conductor core in each wire slot of the cross skeleton is filled with a cotton yarn filling body.

6. A signal compensating instrument cable for a smart substation as claimed in claim 1 or 2 or 5, characterized in that The thickness of the outer shield layer is 0.05mm, which is wrapped flat and the overlapping rate is greater than or equal to 25%.

7. A signal compensating instrument cable for a smart substation as defined in claim 3, characterized in that The thickness of the outer shield layer is 0.05mm, which is wrapped flat and the overlapping rate is greater than or equal to 25%.

8. A signal compensating instrument cable for a smart substation as defined in claim 4, characterized in that The thickness of the outer shield layer is 0.05mm, which is wrapped flat and the overlapping rate is greater than or equal to 25%.

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