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High Voltage Cables: Design & Construction
Sep 9, 2022
A high-voltage cable (HV Cable) is a type of cable used for high-voltage electric power transmission. Insulation and a conductor are components of a cable. Cables are thought to be completely insulated. This indicates that they have a fully rated insulation system, which will include metallic shield, insulation, and semi-conductor layers. An overhead line, on the other hand, might have insulation but is only partially qualified for operational voltage (EG: tree wire). Numerous instruments, ignition systems, and alternating current (AC) and direct current (DC) power transmission systems use high-voltage cables of various types. The cable's insulation must not deteriorate in any application because of high-voltage stress, ozone created by electric discharges in the air, or tracking.
The cable system must contain and manage leakage current as well as prevent the high-voltage conductor from coming into contact with other things or people. To stop the breakdown of the insulation, cable couplings and terminals must be made to control the high-voltage stress.
High-Voltage Cables can be cut to lengths ranging from a few feet to hundreds of feet, with shorter cables used in equipment and larger cables run within buildings, buried in an industrial complex, or used for power distribution. The longest cut lengths of cable will generally be submarine cables under the ocean for electricity transmission
Depending on the length of the circuit and whether a semiconducting jacket is used on direct buried wires, splices in the middle of the cable may also be grounded.
Any voltage greater than 1000 volts is considered a high voltage. Medium voltage cables are typically those between 2 and 33 kV, and high voltage cables are those over 50 kV.
The conductor, the conductor shield, the insulation, the insulation shield, the metallic shield, and the jacket are the only components of modern HV cables. Ripcords, armour wires, and water-blocking tapes are examples of additional layers. Wires made of copper or aluminium carry the current (For a detailed discussion on copper cables, see main article: Copper conductor.) With a few uncommon exceptions, the insulation, insulation shield, and conductor shield are typically made of polymers.
Design of HV Cable
Two qualities emerged as being crucial throughout the development of high voltage insulation, which took around fifty years. The introduction of the semi-conductive layers comes first. These layers must be completely smooth, without even the slightest protrusions of a few micrometers. Furthermore, there must be complete fusion between the insulation and these layers; any fission, air-pocket, or other imperfection, even by a few micrometers, is harmful to the cable. Second, there must be no inclusions, cavities, or other problems of a similar size in the insulation. Any such flaw reduces the cable's voltage life, which is meant to be in the range of 30 years or more.
As a result of collaboration between cable manufacturers and material producers, XLPE grades with exacting standards already exist. The majority of XLPE-compound manufacturers specify an "extremely clean" grade with guaranteed foreign particle quantity and size. It is necessary to pack and unload the raw materials into the cable-making machines in a clean-room setting. Cable-making installations for producing pure and defect-free insulation have been made possible by the introduction of extruders for plastic extrusion and cross-linking.
High Voltage Cable in Brief;
Knowing the actual and physical power of high voltage makes it simple to remember how it operates and is built. For the transmission of electric power, a particular high-voltage power cable is needed because individual conductors carry high voltage. For a standard high-voltage power cable, the following is necessary:
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An operator, or conductor,
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Insulation that can be applied both above and below water
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Ensuring that the high voltage effect is controlled and doesn't cause the insulation to fail in the cable and joints
Structure or appearance of HV cables
The structure of a high-voltage power cable includes one or more conductors, suitable insulation, and a protective jacket. The number of layers in the insulation jacket of the cables might vary depending on the voltage power level in order to control the electric field in the conductor.
Conductors that operate at voltages higher than 2,000 volts frequently employ high-voltage power cables. With this amount in mind, each insulator conductor will have a conductive shield that aids in distributing electrical stress. Because Martin Hochstadter patented this method in 1916, this shield is occasionally referred to as the Hochstadter shield.
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"Stress relief cones" are mounted at the ends of shields.
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100,000 V power distribution cables have good oil insulation.
(This view will change according to HV Cable Suppliers.)
Types of High Voltage Cable
High voltage cables come in a variety of types to suit various uses. Some are essential for the operation of instruments, the transmission of AC and DC power, and ignition systems. A high voltage power cable system is intended to prevent any contact.
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HVDC
Similar to the AC cable, a high-voltage cable for high-voltage direct current (HVDC) transmission has the same design. The test requirements are different from the physics. The semiconducting layers (2) and (4) must be as smooth as possible in this situation. The insulation must still be kept clean.
Since AC can no longer be used at distances of more than about 100 km, many HVDC cables are used for DC undersea connections. The North Sea Link cable, which runs 720 kilometers (450 miles) between Norway and the UK as of 2021, is the longest submarine cable in existence.
Features of HV cables
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High voltage power cables have a few unique characteristics and are designed to function with particular switching and distribution panels.
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They make it possible to manually or remotely switch and control control rooms for the testing of individual supply systems.
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High voltage power cable substations have the ability to reduce the voltage in an effort to distribute it to nearby locations.
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The semiconducting layers should be a few micrometers thick and smooth. Any fission or gap between the layers' fusion and insulation can be extremely hazardous.
Maintenance Tips from The Cable Manufacturer
It is essential to make sure the high-voltage power cable you install for the underground electric transmission system is of the highest caliber.
Make sure the high-voltage power cord you choose is strong enough to resist harsh environments. The materials used for these cables should be of the highest quality and incorporate a variety of energy-efficient technologies because they deal with high voltage and have the potential to deliver severe electric shocks.
Keep track of every cable you use, especially if the environment is industrial. If you keep a record of all your wires and cables, you should have a good idea of when the next maintenance or repair check is due.
High Voltage Cable Manufacturers in Australia: Znergy Cables
Znergy Cable, the leading high-voltage cable producer in Australia, has a cutting-edge high-voltage cable plant that uses upgraded technology. Znergy Cable manufactures high-voltage cables in accordance with AS1802 Cable specifications and standards. Additionally, our knowledgeable research and development staff can help with manufacturing to an international standard for safety purposes.
Also Read: What is High Voltage Cable and Its Used?
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What is Encapsulated Cables & Its Used?
Aug 30, 2022
The durability of Tubing Encapsulated Cables (TEC) is equal to that of its users. To shield electrical and optical components from the pressure and corrosive impacts of the downhole environment, TEC uses welded stainless steel and nickel alloy tubing. Additional mechanical protection is provided by polymeric encapsulation.
The SST data acquisition device on the surface receives power and signals from the downhole gauges using tubing encapsulated cable (TEC). A 16 AWG copper single wire conductor is housed in a 1/4" OD TEC for the SST permanent monitoring system.
Uses of Tubing Encapsulated cables
- The number of metres of wires inside each automobile and truck might be in the hundreds.
- Some of these cables' specific parts need to be protected against moisture, heat, chemicals, and dust, while others essentially need to seal gaps between the cabin's various compartments.
- The so-called "cable grommet" and "wire encapsulation," both manufactured of polyurethane to have high mechanical and technical features, like stability and sealing, accomplish these functions.
- Even though TEC cables are widely used in the oil and gas sector, Galaxy is the fastest manufacturer of these tubing-encapsulated cables.
- Typically, an additional filler layer is extruded over the core wires. After this stage of production, these wires are typically moved to a different facility to be covered in armour.
Encapsulated Cable Manufacturer in Australia
Znergy Cables offers integrated turn-key systems for the traditional RIM method of pouring cables or wires into a mould to create cable grommets and wire encapsulation.
In accordance with customer requirements, Znergy Cables also offer moulds made of various materials and with custom designs.
An overview of Encapsulated Cable
An Encapsulated Cables is a type of electrical cable that is coated with a material that protects the inner cable from damage like scratches and bending.
Conclusion
When different items are required to meet various needs, Znergy Cable offers all available solutions related to Encapsulated Cables and electrical cables under one roof. We offer a wide range of products for use in many markets at the lowest possible cost, in the finest possible quality, and with the shortest lead times. The company considers offering the best possible balance of quality and cost-effectiveness while maintaining the needs of its clients. The capacity of this group to source high-quality materials and produce full custom design solutions is its primary competency.
Also Read: Where are Capillary Tube Used?