aluminum cable

Aluminum alloy Cable in wind farm

by

In recent years, China’s wind power industry has been developing rapidly, and the total installed capacity and annual new installed capacity of wind power are in the forefront of the world. However, due to the harsh environmental conditions of wind farms, the cable terminals, cable bodies, etc. of the power collection lines in the site are prone to failure, so it is necessary to constantly use new materials and processes with advanced technology and reliable performance to improve the operation quality of the power collection lines for the safe and stable operation of wind farms.

The power cable is an important part of the collection line of the wind farm. Generally, there are two types of cable conductors for the wind farm: aluminum core and copper core. Aluminum core cable and copper core cable have their own shortcomings. The disadvantage of aluminum core cable is poor flexibility, and it is easy to break after repeated bending; Poor stability, easy to be corroded and oxidized; High resistivity, high energy consumption and large loss compared with copper cores of the same section; Poor ductility, inconvenient installation, etc. The disadvantage of copper core cable is its high price; Heavy weight; High construction and transportation costs.

Based on the above situation, domestic cable manufacturers have started to produce aluminum alloy cables. At present, there are more than 10 domestic enterprises producing aluminum alloy cables. In fact, as early as 1968, the American Southern Cable Company invented aluminum alloy cable. The United States, Canada and other countries have had more than 40 years of application history. Therefore, it is necessary to analyze the use of aluminum alloy cable products in order to improve the operation quality of the collection line of the wind farm and reduce the project cost.

 

Analysis of Characteristics of Aluminum Alloy Cable

The main components of the conductor of aluminum alloy cable are: copper, iron, silicon, magnesium, manganese, titanium, chromium, zinc, rare earth, etc. The role of copper increases the resistance stability of the conductor at high temperatures; The role of iron is to increase the creep resistance of conductor; The function of magnesium is to improve the tensile strength of conductor; The function of rare earth is to improve the corrosion resistance of conductor. 5083 aluminum alloy plate is also widely used in wind power generation and can be used as the pedal of wind tower

 

1、 Electrical performance of aluminum alloy cable

（1） Conductivity: The conductivity of aluminum alloy is between aluminum and copper, inferior to copper and slightly superior to aluminum.

（2） Cable compression characteristics: aluminum alloy conductor adopts layered compression stranding technology, and the compression coefficient of conductor can reach 0.93, while the compression coefficient of copper conductor is generally only 0.80. The maximum limit compaction can make up for the shortage of aluminum alloy conductor in volume conductivity, so that the stranded conductor core is like a solid core, which significantly reduces the outer diameter of the core and improves the conductivity. Therefore, when the ampacity is the same, the outer diameter of the cable after aluminum alloy cable replaces the copper core cable does not increase much.

 

2、 Mechanical properties of aluminum alloy cables

The elongation of hard pure aluminum is very low, and it is easy to be damaged or broken during repeated bending. The elongation of soft pure aluminum is much higher than that of hard pure aluminum, but its yield strength is only half that of copper, and its creep resistance is poor. After installation for a period of time, the connection is easy to relax, resulting in increased contact resistance, forming a hidden danger for safe operation. Through the comparison in Table 1, it can be concluded that the mechanical properties of aluminum alloy conductor have the following advantages:

（1） High extension. The elongation of aluminum alloy conductor after annealing can reach 30%, which is close to copper but much higher than aluminum. This also shows that aluminum alloy conductor can withstand greater external forces than aluminum conductor.

（2） Strong and flexible, easy to bend. During installation, aluminum alloy conductor has smaller bending radius than aluminum conductor, which makes it easier to connect terminal blocks.

（3） Good creep resistance. The creep resistance and compactness of the alloy elements in aluminum alloy have been greatly improved after special process treatment. When the conductor encounters extreme conditions such as cold flow, overload and overheating, stable connection can also be ensured.

 

3、 Corrosion resistance of aluminum alloy cable

The rare metals added in the aluminum alloy conductor further improve the corrosion resistance of metal materials with aluminum as the conductor in terms of chemical properties, and reduce the potential difference between different metals. The smaller the potential difference, the lighter the corrosion will be. The rare earth elements in alloy materials can play a role in filling surface defects, refining grains, and eliminating local corrosion of conductors. At the same time, they also bring negative electrode potential shift of aluminum, which has an anodic effect, thus greatly improving the corrosion resistance.

 

4、 Economic performance of aluminum alloy cable

Compared with copper cable, the price advantage of aluminum alloy cable is also obvious. The price of aluminum alloy cable with the same ampacity is only 60% – 70% of that of copper cable. In addition, due to the light weight, the installation cost is indirectly reduced.

Selection of 35kV cable conductor in wind farm

For 35kV high-voltage cables used in the wind farm, in order to save the project cost, aluminum core is preferred as the conductor. On the premise of meeting the voltage drop and the corrected ampacity, the economic current density is used to calculate the appropriate cable cross-section.

With the increase in the number of wind farms and the passage of operation time, the disadvantages of aluminum core cables gradually emerge, mainly in the following aspects:

1、 Poor mechanical strength, easy to break. The area where the wind farm is located is in a harsh environment with high wind speed, and the wind load on the cable after it is mounted on the tower is large. In particular, due to the influence of umbrella groups, the wind surface at the cable terminal is larger, so it is easier to have failures. The connection of cable and wire is shown in Figure 1.

2、 The creep resistance is poor. After the wind farm cable is installed on the tower, when the current passing through the conductor is too large, the aluminum conductor will become hot and creep, and the cable joint is easy to become loose and deformed, resulting in poor line contact, which will cause line and equipment failure accidents.

3、 High resistivity and high loss. The cable conductor section is selected for the wind farm. The aluminum core section is much larger than the copper core section. For example, if the cable section is too large and the cable length far exceeds the maximum production reel length of the cable manufacturer, the number of cable sections and intermediate joints will increase, which is unfavorable for the long-term operation of the collector line.

Based on the above reasons, the power cables in wind farms in recent years mainly use copper cores. Copper core cables can solve various problems of aluminum core cables. However, in recent years, China’s demand for copper materials has gradually increased, and copper prices have also been rising, which has virtually increased the cost of many projects and increased the risk of stolen cables at the construction site. In addition, due to the heavy weight of copper core cables, the requirements for cable supports are also high.

Compared with aluminum core and copper core cables, aluminum alloy cables do have many advantages and can replace them in many occasions. In addition, aluminum alloy conductors have been added to the GB/T3956-2008 Conductor of Cables. Therefore, it is theoretically feasible to use aluminum alloy cables in the collection lines of wind farms.

However, there are still some problems to be solved in the massive promotion of aluminum alloy cables in wind farms:

Aluminum alloy conductors have various models according to the chemical composition added, but there is no description of the added chemical composition in the domestic specifications, so the products are easy to be different in bidding and actual supply.

Due to the different expansion coefficients of aluminum alloy, aluminum and copper conductors, different conductors should not be directly connected. Transition terminals are required to ensure the reliability of the connection between aluminum alloy conductors and copper and aluminum conductors, which increases the risk of use.

There are few application cases of aluminum alloy cables used in wind farms. Whether aluminum alloy cables are more reliable than aluminum core and copper core cables in applications in special areas such as high temperature, cold, high altitude, high salt spray, and high temperature difference also requires time to test.

 

Epilogue

After the above analysis, aluminum alloy cable has good conductivity and excellent mechanical properties, which improves the unreliable connection, poor mechanical properties and easy creep of aluminum core cable. However, considering that there are still some problems of aluminum alloy cables that need to be improved and solved, it is suggested that the wind farm should try out aluminum alloy cables in a part of the collector line or in a certain transmission circuit according to the site conditions, especially in the technical transformation of the early wind farm. Through comparison under the same operating environment, we can know whether its line loss, failure rate and other aspects are better than copper core and aluminum core cables, It will provide practical experience for future promotion.

We have reason to believe that the use of aluminum alloy cables in specific occasions is the development trend of the cable industry in the future after time inspection and gradual improvement of relevant regulations and specifications.

Strict environmental protection is conducive to aluminum promotion

by

1. Huge aluminum processing capacity.
From 2006 to 2016, the accumulated investment in fixed assets of nonferrous metal alloy manufacturing and calendering industry exceeded 2201.4 billion yuan, with an average annual growth rate of 26.97%, of which the proportion of aluminum processing investment basically remained above 45%. A large amount of investment has led to the rapid growth of production capacity (at present, China’s aluminum extrusion production capacity accounts for 76% of the world’s total production capacity; the casting hot rolling production capacity accounts for about 59% of the world’s total production capacity; and the twin roll continuous casting and rolling strip production capacity accounts for about 67.5% of the world’s total production capacity). The export volume of aluminium sheet, aluminum foil and aluminum strip also ranks among the top in the world, with the largest number of world-class equipment.

At present, China has the world’s largest and full range of aluminum surface treatment production lines, the largest number of Sigmak heavy extruders, CVC cold rolling mills, the largest number of Ashenbach aluminum foil mills, and the largest number of hot and cold continuous rolling mills. However, how to make full use of these advanced equipment and play their due role will test the creativity, imagination and ability of industry personnel. Otherwise, it will add a heavy burden.

2. Homogeneous price competition is becoming increasingly fierce.
A lot of investment is focused on high-end aluminum strip and large extrusion products, resulting in structural overcapacity. The more high-end products, the more excess. As a result, product homogeneity competition and price war become increasingly fierce. This phenomenon is widespread from low-end products to high-end products. For example, in recent years, due to homogeneous competition, the processing cost of some products with high added value has become lower and lower. For example, the processing cost of CTP printed board base has dropped from 12000 yuan/ton to 3800 yuan/ton; The processing cost of aluminum alloy can materials has decreased from the original 20000 yuan/ton to less than 4000 yuan/ton; The processing cost of aluminum alloy profiles for high-speed railway carriages has decreased from 50000-70000 yuan/ton to 10000-15000 yuan/ton.

3. There is a good policy environment for the development of aluminum processing.
The Made in China 2025 issued in 2015 and the 13th Five Year Development Plan for Nonferrous Metals Industry to be released clearly propose to accelerate the development of high-performance light alloy materials. As the most important lightweight, energy-saving, renewable and environment-friendly material, aluminum alloy is the first choice in aviation, automobile, construction, electronics and packaging industries.

The General Office of the State Council recently released the Guiding Opinions on Creating a Good Market Environment, Promoting the Restructuring of the Non ferrous Metals Industry, Promoting Transformation and Increasing Benefits, which also clearly proposed to further increase the consumption of non-ferrous materials in aviation, automotive, construction, electronics, packaging and other fields, and focus on the development of aluminum alloy plates for passenger vehicles, aviation and marine use.

Therefore, with the deepening of supply side structural reform, the business environment for the development of China’s aluminum processing industry will be improved.

The Ministry of Industry and Information Technology said that while supporting the expansion of aluminum consumption in traditional areas, it would continue to implement major special projects such as technological transformation, foundation strengthening projects and new materials closely related to the aluminum processing industry, and would also increase targeted and continuous support for key areas such as aviation aluminum materials and car panels. The Ministry of Industry and Information Technology has also successively introduced some specific policies and measures to support the expansion of aluminum application in recent years. For example, at present, aluminum alloy semi trailers and tank cars can enjoy the policies of energy conservation and emission reduction in transportation, recommended models for highway drop and hook transportation, vehicle and vessel tax reduction and exemption. Aluminum alloy heat insulation profiles, color aluminum plates, aluminum alloy building templates, etc. are listed as green building materials.

Difference between aluminum alloy and aluminum profile

by
Difference between aluminum alloy and aluminum profile

Aluminum alloy is a kind of aluminum material, and it is also mixed with other metals, which is an alloy material. The aluminum profile is a product, which is made of aluminum alloy or pure aluminum, and can be directly used in the field of decoration. 2. The uses of the two are different, and the corrosion resistance, electrical conductivity and recyclability of aluminum profiles are more superior.

Difference between aluminum alloy and aluminum profile

In the building materials market, one is aluminum alloy, and the other is aluminum profile. Although there are many similarities between the two, there are still some differences. Today, Xiaobian will introduce aluminum alloy and aluminum for you. What is the difference between profiles.

The following article explains aluminum profiles in detail

Great prospects for the application of aluminum profiles

1. What are the differences between aluminum alloys and aluminum profiles?

The most direct difference is that the definitions of the two are different. Aluminum alloy is a kind of aluminum material, and it will also be mixed with other metals. It is an alloy material. The aluminum profile is actually a product, which is made of aluminum alloy or pure aluminum, and can be directly used in the field of decoration. The uses of the two are different, and the corrosion resistance, electrical conductivity and recyclability of aluminum profiles are more superior.

Difference between aluminium alloy and aluminum profile

2. What are the characteristics of aluminum profiles

①. Aluminum profiles made of pure aluminum have very good corrosion resistance, because the density of this material is 2.7 per cubic meter. If it is pure aluminum, it has very good corrosion resistance.
②. In addition, the conductivity of this material is also very good. Compared with other materials, the conductivity of aluminum is twice that of copper.
③. The thermal conductivity of aluminum profiles is also relatively prominent, so it can be made into a variety of utensils, such as cooking utensils, and our spatula can be made of aluminum alloys into an aluminum profile, including auto parts, etc. Etc., as well as radiators, are made of this material.
④. The processability of aluminum profiles is also very good, which can maintain the characteristics of the material.
⑤. Because this aluminum profile has a certain recyclability and can be reused, it is widely used in many aspects. It is also used in the furniture market and medical equipment, including some automated machinery and equipment.

3.The classification characteristics of aluminum alloys.

If it is divided according to its production process, it can be divided into deformed aluminum alloy or cast aluminum alloy. If it is a deformed aluminum alloy, there are also different products. For example, one is to prevent rust. Each has its own advantages and disadvantages, and the scope of application is also different.

Common products of aluminum profiles include: aluminium plate,  aluminium coil, aluminium foil, aluminium strip, etc

Basic characteristics of aviation aluminum alloy

by

The main characteristics of aluminum alloys for aerospace are: large-scale and integration, thin-walled and lightweight, precision of section size and geometric tolerance, uniformity and quality of microstructure and properties. According to different service conditions and parts of aircraft, aluminum alloys for aerospace are mainly high-strength aluminum alloy, heat-resistant aluminium alloy and corrosion-resistant aluminum alloy. High strength aluminum alloy is mainly used for aircraft fuselage components, engine compartment, seats, control systems, etc., and is the most widely used,For example, 5086 aluminum alloy.

characteristics of aviation aluminum alloy

The biggest characteristic of aviation aluminum alloy is that it can improve the strength by deformation heat treatment. Deformation heat treatment is a comprehensive process that combines the deformation strengthening of plastic deformation with the phase transformation strengthening during heat treatment to unify the forming process and formability. During the plastic deformation process of aviation aluminum alloy, the defect density inside the crystal increases, and these crystal defects will cause the change of the internal microstructure of the material. In the process of plastic deformation of aviation aluminum alloy, dynamic recovery, dynamic recrystallization, sub dynamic crystallization, static recrystallization, static recovery and other crystal structure changes will occur. These changes in crystal structure, if properly controlled, will significantly improve the mechanical properties of the material and enhance the service life of the material.

Aeronautical aluminum alloys are generally strengthened by precipitation of dispersed phase in supersaturated solid solution. The general precipitation sequence is: segregation region (or GP region) ~ transition phase (metastable phase) ~ equilibrium phase. In the process of deformation heat treatment, deformation induces precipitation, precipitation affects deformation, deformation and precipitation affect each other, and dynamically affect the properties of the material.

characteristics of aviation aluminium alloy

The precipitation strengthening process of deformation heat treatment is greatly affected by temperature. Deformation heat treatment can be divided into high temperature deformation heat treatment and low temperature deformation heat treatment. The basic processes of low temperature deformation heat treatment are: quenching of aviation aluminum alloy, cold deformation at room temperature and aging heat treatment. After this treatment, the strength of aviation aluminum alloy is greatly improved, but the plasticity is reduced. High temperature deformation heat treatment process: quenching, high temperature deformation and aging. After high temperature deformation heat treatment, the strength of the material is higher, the plasticity and toughness are improved, and the heat resistance strength of the alloy is also improved.

Basic knowledge of aluminum alloy materials

by

Aluminum plate refers to the rectangular aluminum plate sheet made of pure aluminum or aluminum alloy through pressure processing (shearing or sawing) to obtain rectangular cross section and uniform thickness Internationally, it is customary to call aluminum materials with thickness of more than 0.2mm, less than 500mm, width of more than 200mm and length of less than 16m as aluminum plate or aluminum sheet, less than 0.2mm as aluminum foil and width of less than 200mm as row or strip (of course, with the progress of large equipment, there are more rows with width of 600mm).

aluminium sheet

Aluminum plate is usually divided into the following two types:

1 According to the alloy composition, it can be divided into: high-purity aluminum plate (rolled by high-purity aluminum with a content of more than 99.9), pure aluminum plate (basically rolled by pure aluminum), alloy aluminum plate (composed of aluminum and auxiliary alloys, usually aluminum copper, aluminum manganese, aluminum silicon, aluminum magnesium, etc.) composite aluminum plate or welding plate (aluminum plate materials for special purposes are obtained by means of multiple material composites) aluminum clad aluminum plate (thin aluminum plate is coated on the outside of aluminum plate for special purposes)

2. According to the thickness, it is divided into: (unit mm) thin plate 0.15-2.0, conventional plate 2.0-6.0, medium plate 6.0-25.0, thick plate 25-200, five rib pattern aluminum plate and ultra thick plate more than 200

3.Common aluminum plate grades include 5083, 5086, 5754, etc.

How to determine whether to use 6 / 10 or 8.7/10 for cable selection

by

When selecting cables, the power cable line design, installation and operation departments shall consider four factors, such as cable service conditions, insulation level, AAAC Cable type and conductor section, which are divided as follows.
1. Cable service conditions
(1) cable rated voltage / u () shall meet the following requirements:
1) the voltage shall meet the requirements of neutral grounding mode of power system, that is, in the neutral ungrounded power system, the voltage of non fault phase increases by times in case of single-phase grounding fault, which is related to the troubleshooting time of system grounding fault.


In IEC standard, power system is divided into three categories. Class a means that any phase conductor of the system is grounded and can be separated from the system within lmin; Class B refers to the grounding of single-phase conductor in the system, the allowable grounding fault time shall not exceed 8h, and the annual cumulative time shall not exceed 125h; Class C is a system that does not belong to classes a and B.
when the cable is used in the neutral effective grounding system, u takes the phase voltage value of the system. For example, 6 / 10kV cable is selected for 10kV system and 21 / 35kV Cable is selected for 35kV system.
When the cable is used for neutral non effective grounding system, the cable with one level higher than the system phase voltage shall be selected. For example, 8.7/10kv cable shall be selected for 10kV system and 26 / 35kV Cable shall be selected for 35kV system.
When the cable is used in class C system and single-phase grounding is allowed for long-term operation, u shall select the line voltage of the system, such as 6 / 6kV cable in 6kV system.
2) the voltage U and shall be equal to or greater than the rated voltage and maximum working voltage of the system where the ACSR Cable is located.
(2) cable transmission capacity. The cable line must meet the transmission capacity of the power system, that is, the selected cable shall have long-term allowable current carrying capacity to meet the system requirements.
For longer cable lines, the line voltage drop of the cable shall also be considered.
(3) cable laying conditions. Cables shall adapt to different laying methods, arrangement methods, metal sheath grounding methods and surrounding medium temperature, etc. The conductor of XLPE cable used for underwater laying shall have longitudinal water resistance. In order to meet the requirements of various laying environments, such as tension, compression, fire prevention, termite prevention and rodent prevention, the armor layer and outer sheath of the cable shall be made of corresponding structural materials.


2. Basic insulation level of cable
the peak value of lightning impulse withstand voltage between each conductor of the cable and the shield or metal sheath, i.e. the basic insulation level bil, shall comply with the provisions in table 1-13.
picture
in table 1-13, the lightning impulse withstand voltage of 220kV and above cable lines has two values, which can be selected according to the protection characteristics of arrester, the characteristic length of impulse wave of cable line and the lightning impulse insulation level of connected equipment.
3. Cable type
(1) comparison of insulation properties between XLPE and oil paper cables. XLPE insulated cable has the advantages of simple production process, short manufacturing cycle, easy installation and maintenance, excellent electrical performance and large transmission capacity. In recent 30 years, the technology of XLPE insulated cable has developed very fast and has been widely used. In terms of insulation performance, compared with oil paper insulation, cross-linked polyethylene insulation has some different characteristics, which are listed in table 1-14.
picture
Note: “air raid” should be “gap”
Oil paper insulated cable has the advantages of excellent electrical performance and long service life. It can be used in general occasions. However, compared with XLPE cable, the manufacturing and installation process of oil paper ABC Cable is more complex and the cost is higher.
oil filled cable with paper plastic composite insulation with low dielectric loss and alkylbenzene synthetic oil with good aging resistance as insulation structure, suitable for voltage levels of 220kV and above. In addition, oil paper insulated cables are also suitable for HVDC transmission lines.
(2) for cable lines of 110kV and below, XLPE insulated cable is generally the preferred variety. For distribution cables of 1kV and below, in addition to polyvinyl chloride (PVC) insulated cables for lines with light load, cross-linked polyethylene insulated cables shall also be selected.
Note: at present, 1-500 cables are mainly XLPE cables, and only some stocks of oil paper insulated cables and oil filled cables are left.


(3) ethylene propylene rubber (EPR) insulated cable is suitable for 35kV and below lines. This kind of cable is suitable for underwater laying because of its good moisture resistance, but its price is expensive.
4. Conductor section
copper conductors are generally used for power cables. The selection of conductor section shall meet the requirements of cable line transmission capacity and maximum short-circuit thermal stability of the system at the same time. And comply with “economic optimization of cable conductor size”.
in urban low-voltage power grid, four core cable is generally used, that is, in addition to three-phase conductor, there is a neutral line passing through three-phase unbalanced current and having protective grounding effect. The section of neutral wire shall generally be 30% ~ 60% of the conductor section of each phase. In the low-voltage power grid with large three-phase unbalanced current, four core low-voltage cables with equal cross-section shall be selected. The three core cable plus another insulated conductor cannot be used as the neutral wire to connect to the three-phase four wire low-voltage power grid, because in this way, there will be unbalanced current passing through the metal sheath and armor layer of the three core cable to heat it, thus affecting the transmission capacity of the cable.

Factors Affecting Cable Performance and Placement in Wiring

by

Factors affecting Aerial Bundled Cable (ABC) SANS 1418 Standard and placement in the wiring six factors affecting cable performance:

  • Ultraviolet (UV)– Do not use cables without UV protection in direct sunlight.
  • Heat — The temperature of the cable in the metal tube or groove is very high, and many polymeric materials will degrade their service life at this temperature.
  • Water — moisture in a twisted-pair cable on a LAN can increase the capacitance of the cable, thereby reducing the impedance and causing near-end crosstalk problems.
  • Mechanical damage (repair cost)– Cable repair is very expensive and requires at least two terminations at each break point.
  • Grounding — If the shielding of the cable needs to be grounded, the appropriate standards must be complied with.
  • Total length of routing (not just between buildings)– Outdoor LAN twisted pair cables are used between buildings and the total length is limited to 90 meters. For 100Mbps or 1000Mbps networks, the paved distance cannot exceed this limit. If the laying distance is between 100 meters and 300 meters, optical cable should be chosen.

Is the cable placed in:

1.Under the eaves. 4/0 Aluminum Cable can only be used when they are not directly exposed to sunlight or ultra-high temperatures. Standard LAN cables are recommended.

  1. Exterior wall. Avoid direct sunlight exposure to the wall and man-made damage.
  2. In pipes (plastic or metal).If in pipes, pay attention to the damage of plastic pipes and the heat conduction of metal pipes.
  3. Hanging applications/overhead cables. Consider cable sag and pressure. What kind of binding do you plan to use? Whether the cable is exposed to direct sunlight.

  1. It is directly laid in the underground cable trench, which is the least controlled environment. The installation of cable trench should be checked regularly for dryness or humidity.
  2. Underground pipes. In order to facilitate future upgrades, cable replacement and isolation from surface pressure and surrounding environment, auxiliary pipe isolation, auxiliary pipe is a better method. But don’t expect the pipes to stay dry forever, which will affect the type of cable you choose.

International Advanced Level of Environmental Protection Wire and Cable Indicators

by

Environmental protection wire refers to the material is environmental protection wire.

The material includes insulating material, conductor material and shielding material. Insulation such as PVC, irradiated cross-linked PVC (XL-PVC), irradiated cross-linked polyethylene (XL-PE), low smoke free (Halogen-free), silicone rubber, Teflon Telflon and so on. The environmental protection of insulation materials is mainly the EU’s RoHS environmental protection directive and the EU’s environmental regulations on children’s toys do not contain 6P (Non-6P), that is, does not contain phthalates. Now the most environmentally friendly is low smoke halogen-free, does not contain halogen elements.

The most common conductor material is copper. Copper has bare copper (brass, red copper), tinned copper, silver-plated copper wire, etc., which are essentially copper, but the surface is plated with other substances. Now there are copper – coated aluminum and copper – coated steel conductors on the market. If the electrical performance requirements are high, copper is the best. The environmental protection of conductors is mainly required to be free of heavy metals (RoHS).

Environmental protection cable means that it does not contain lead, cadmium, hexavalent chromium, mercury and other heavy metals, and does not contain brominated flame retardants. The environmental protection performance of the cable is tested by SGS recognized testing institutions, and it is in line with the European Union Environmental Protection Directive (ROSH) and higher than its index requirements. No harmful halogen gas, no corrosive gas, less fever when burning, no pollution of soil wires and cables.

Main technical indicators:

  1. Rated voltage: 450/750V and below
  2. The maximum permissible operating temperature of the conductor shall not exceed 70 ℃, 90 ℃ and 125℃ respectively.
  3. Cable combustion smoke density in line with GB/T 17651-1998 (equivalent to IEC1043) standard requirements, light transmittance ≥60%.
  4. Cable halogen acid content test conforms to GB/T 17650-1998 (equivalent to IEC 754-2) standard requirements.

(1) PH ≥4.3

(2) Conductivity ≤10μs/mm

  1. The flame retardant performance of the cable conforms to the requirements of GB/T 12666-1990.

6.Toxicity index of cable ≤3.

Cable selection method of generic cabling system

by

Generic cabling is one of the key links of information network system. In order to ensure the high-speed and stable operation of information network system, it is particularly important to select high-quality and high-performance cables.

The cable selection should be based on the system requirements, technical performance, investment estimates and other factors, but in the wiring system, it should first determine the type of cable used and the structure of wiring (unshielded cable, shielded cable, optical cable or mixed use). Cables usually use Aluminum conductors with insulation and one or more layers of plastic sheath. The cable usually consists of 2 to 3600 pairs. Large logarithmic cables are usually used in backbone cabling systems and are suitable for voice and low rate data transmission. The maximum lengths of these cables for trunk and horizontal (hub to desktop) cabling systems are specified in the latest GB 50311-2007. It should be noted that these maximum length limits apply to all media. They do not consider the impact of performance differences due to different cable types and protocol types used in the network. In fact, the maximum cable length will depend on the application of the system, the type of network and the quality of the cable.

Method of cable selection in generic cabling system

Since it is a building, it will definitely use a lot of communication cables. As the nervous system of intelligent building, generic cabling system is the key part and infrastructure of intelligent building. It has a very close relationship with the planning and design, construction, installation and maintenance of construction engineering. It is like an information superhighway in the building. People can communicate and communicate conveniently, quickly and effectively. It can be said that the generic cabling system connects the communication, computer and various facilities and equipment in the intelligent building to form a complete set of whole, so as to meet the requirements of highly intelligent.

But then we have to consider a problem: fire prevention. Once a fire breaks out in the building, the heat and gas released by these cables will become a major safety hazard. Looking at several large-scale fire accidents in China in recent years, many of them are due to the fact that the victims can’t escape. The burning of cables emits poisonous acid gas. In addition, a lot of heat and smoke are released from the combustion, which makes it difficult for the victims to breathe and lead to tragedies. Therefore, in addition to considering the performance, fire protection and environmental protection are also very important reference factors when we select cables for generic cabling system.

The global subsea power cable market will grow at a compound annual rate of over 4% from 2020 to 2024

by

The market for subsea power cables is expected to grow at a compound annual rate of more than 4 percent from 2020-2024, driven largely by surging demand for electricity, according to Technavio.

According to the report, 47 percent of the market growth in the forecast period will come from Europe, with Italy, Denmark and Finland being important markets for European subsea power cables.

Europe is the largest subsea power cable market in 2019, and government support and growing concern about wind power will significantly drive growth in the subsea power cable market in the region during the forecast period.

Offshore wind turbines can produce more energy using fewer turbines than conventional ones. As a result, the Asia-Pacific region will enjoy rapid growth during the forecast period. Thanks to heavy investment in offshore wind projects over the past few years, China and India will account for most of the region’s share of the forecast period.

According to the IEA, demand for electricity will rise by 40 per cent by 2024. Similarly, growing environmental concerns will force economies to use renewable energy to generate electricity. As a result, the number of renewable projects such as wind and tidal power projects is increasing in most countries, which in turn will increase the demand for undersea power cables or submarine cables. The growing demand for intercountry and island connections will be one of the main drivers of market growth. Subsea power grid interconnection projects in France – UK, Belgium – UK and Ireland – UK are under construction.

On the other hand, the growing demand for high-voltage direct current (HVDC) power cables will also drive the market growth. These HVDC cables are more and more popular compared with traditional cables because they are safe and reliable and can transmit power over long distances. These factors will drive the global subsea power cable market to grow at a compound annual rate of over 4% over the forecast period.

From the manufacturers’ point of view, Prysman, Nexans, Sumitomo Electric, Lenny Cable, Ankart Cable, Tengura Cable, Guhe Electrician, LS cable will continue to dominate the global subsea power cable market in the forecast period.