Tang Songbai: Aluminum alloy conductor power cable

From November 15 to November 17, 2012, the first annual meeting of the first National Transmission and Distribution Technology Network and the 2012 China Transmission and Distribution Technology Innovation and Application Exchange Conference were held in Beijing China Science and Technology Centered on “Integration of Development and Quality Control”. The grand opening of the hall. The annual meeting was hosted by the China Electric Power Enterprise Association Science and Technology Development Service Center and the National Transmission and Distribution Technology Cooperation Network, and Guoyan Zhongdian (Beijing) Consulting Co., Ltd. organized the event.

According to the organizers, this meeting has gathered hundreds of related management and technical personnel from power generation companies, power grid companies, research institutes and related equipment manufacturing companies across the country. During the three-day annual meeting, the organizers will carry out a number of special forums, technical seminars, technical seminars, technical inspections, and interactions between the supply and demand sides and other activities, aiming to build a cooperation and exchange for supply and demand sides of power companies. platform.

At the meeting, Tang Songbai, Deputy Chief Technical Officer of Far East Cable Co., Ltd. made a speech on the topic of research and development and application of aluminum alloy cables. The speech is as follows:

Tang Songbai: Leaders, experts, good afternoon. I mainly introduce our company and the work we have done in the research and development of aluminum alloy wires and cables in the past two years. Far East Cable is a listed company specializing in the production of wire and cable. It was established in 1990 and covers an area of ​​more than 1,000 mu. The total assets are 6.917 billion yuan. The sales volume in 2011 was nearly 20 billion. The production and sales ranked first in the country for 15 years in a row, becoming China's cable industry. Industry leader. We have ultra-high voltage cross-linked cables, high-voltage cross-linked cables, medium-voltage, low-voltage cross-linked cables. Fire-resistant cables, marine cables, and offshore cables. Special cables include nuclear grade cables, wind power cables, and data control cables. The development of Far East Cables in the past 20 years has seen rapid progress. We have applied many of our products in various industries, such as rail transportation, power stations, and petroleum and petrochemical applications. Here we will briefly introduce the Far East Cable Technology Research Institute. Far East Cable's Technical Research Institute is a state-certified enterprise technology center. It is a Jiangsu Provincial Engineering Technology Research Center. It has 680 technical R&D teams and has a national testing center. More than 30 items are passed through the appraisal each year, and the number of authorized patents exceeds 50 each year. There are academician workstations and postdoctoral workstations.

Below, I have developed a new product in the past two years, but also we think that the application of the building system is more extensive, but in our power system is relatively small, aluminum alloy conductor power cable to make a report to everyone.

First of all, from the perspective of the resources of our country, our country is a country with very little copper resources. At present, the vast majority of copper materials are relied on imports. On the contrary, aluminum resources are abundant. At present, our country’s aluminum mining and smelting processing technology All walk in the forefront. We compare the technical economics of copper and aluminum alloys. Aluminum has a conductivity of 61% of copper, a density of 30% of copper, and a mechanical strength of 40% of copper. When the resistance per unit of length is the same, the cross section of the aluminum conductor is copper. 150% of the conductor, and its corresponding weight is only 42% of copper. According to the current market price, the cable purchase price is 50% of copper.

The main problems of the pure aluminum cables we used in the past, we have many problems in the safety of electrical appliances, and even caused a relatively large fire, then the main reason is that when the conductors are connected, because the long-term Under operating conditions, aluminum wire produces high temperature changes, which can adversely affect the safe operation of the cable. The following table is a comparison of the mechanical properties of copper and aluminum. It can be seen from the table that the elongation of hard pure aluminum is very low, and its flexibility is poor in cable applications.

Aluminum alloy conductors have several advantages. Conductivity of aluminum alloy conductor cables is 61% of that of commonly used reference materials. Electrical connections made with this alloy conductor are as stable as copper. Copper aluminum alloy connectors are used for cable connection, which greatly reduces the problems caused by the difference in thermal expansion of copper and aluminum. The aluminum alloy conductor of the cable meets the requirements of indoor electrical connection by the thermal cycling experiment and mechanical performance test specified in the standard. At present, the voltage rating of aluminum alloy cables developed by our company ranges from 1,000 volts to 30,000 volts, from 10 squares to 1,000 square meters. The first few pictures below are medium voltage 10,000 volts, which are solid conductor aluminum alloy cables.

The following briefly describes some of our considerations in the design of aluminum alloy cables. First of all, our aluminum alloy design index is this. This is the design index of copper conductors. This is the design index of aluminum conductors and all of them are relatively large compared to the original aluminum. improvement of. This is our aluminum alloy formulation, which we developed ourselves. It is the addition of elements such as copper, iron, magnesium and other elements in the conventional aluminum material. Here this chart, this is our copper, the middle is pure aluminum, the rightmost one is our aluminum alloy, we developed the deformation of the aluminum alloy, the deformation of pure aluminum is more obvious from these three figures. , then we developed this aluminum alloy, this performance is similar to copper. This is the idea of ​​our conductor design. The first is to ensure the same electrical transmission capacity, the profile of the conductor is 1.1 times the outer diameter of the copper conductor, and the outer diameter of the cable of the solid solid aluminum alloy conductor is outside the copper conductor. 1.07 times the diameter. Considering the same conductor cross section, the structure of the concentric strands of the profile is 96% of the outer diameter of the copper conductor, and the outer diameter of the single solid aluminum alloy conductor is 94% of the copper strand and the conductor.

This is our main stranding equipment. In fact, the only difference between the aluminum alloy cable and our conventional cable is that it is on the conductor. Our frame stranding machine is a major equipment to complete the conductor production. This is our test report. In the past two years, 1500 aluminum alloy cables and 35,000 aluminum alloy cables passed the identification.

There are many applications of aluminum alloy cables in foreign countries, and there are few applications in our country. You are like this picture mainly introducing the application of aluminum alloy cables in Thailand, Saudi Arabia, Europe, Korea, Japan and America. Its aluminum alloy cable accounts for the percentage of its entire cable usage, so the minimum is also close to 50%. So what is the situation in our country now? In our country, the annual demand for wire and cable can exceed 1 trillion yuan each year, so the conversion to wire and cable may be at the level of 700 billion yuan. The use of aluminum alloy cables in our market is mainly due to the use of building systems. At present, our domestic level is still less than 20 billion yuan. If we use this piece of power cable, especially in the power system, we will increase our use of power. Then we increase this percentage of aluminum alloy cable to 5%. The amount is very impressive. At the same time, the use of aluminum alloy cables has increased, which is beneficial to the reduction of our construction costs, energy conservation, and environmental protection. Its carbon dioxide emissions have been significantly reduced, which is also conducive to the transformation and upgrading of our wire and cable. The Non-Ferrous Metals Industry Association has already proposed today that 2013 is a promotion year for our country's aluminum alloy cables. Therefore, at this meeting we also called for increased use and increase in power systems, with the support of leaders and experts. Application, support for our industry. This is the product of the supporting situation, there is a copper-aluminum alloy transition joints, distribution box connection, this is a laying pattern.

This simple economic analysis, the first is manufacturing, from the transmission of the same power capacity, then the aluminum alloy conductor cable manufacturing cost is only 50% of the copper cable, from the installation point of view, aluminum alloy cable The proportion is 30% of copper, which greatly reduces transportation costs and installation costs. From an operating point of view, the aluminum alloy has a relatively low specific gravity. In addition to the modification, the compressive and tensile properties are relatively high, so that it can be directly laid, and one of them can provide the stability of our operation. The other is the aluminum alloy, which has a melting point of 23 degrees, which greatly reduces the energy consumed and the carbon dioxide released. From this perspective, it should be worth promoting. There are also several processes in the use of aluminum in our country. For example, in the 60s and 70s, our country advocated replacing aluminum with copper. After eight years, we have used copper in large quantities. At present, our country’s copper resources are scarce and large. Some of them are imported, and the price of copper, from my experience point of view, appeared at a stage of 1 ton of 16,000, the highest reached 88,231 tons at such a stage, so from this country's development strategy, from The current product upgrade, from the perspective of the country's carbon dioxide emission reduction, the current active use of aluminum alloy cable products should be of great significance.

The following describes the choice of aluminum alloy cable specifications. One is aluminum alloy cable, copper cable 25 square is 0.727, aluminum alloy cable than the copper cable diameter is 10% larger, the cost is only 50% of copper cable, which is our choice of aluminum alloy cable instead of a copper cable program.

In terms of transportation, we can't ignore it. Aluminum alloy cables have a great cost advantage in the transportation and laying process. This is the installation of aluminum alloy cables. This is the aluminum alloy control connector. This is the T-connection of the cable. Is a schematic diagram of the joint, this is our company in the past two years, in the application of aluminum alloy cable above some of the situations. From June 2011 to now, the scope of application is still relatively wide, but it may be applied more in building systems and less in power systems. Therefore, we hope that the leaders and experts of the application of aluminum alloy cable, we actively cooperate with you, for your service, to provide better products. Far East Cable has always been committed to providing users with the most reasonable and most economical cable usage plan for the power system. Thank you for your leadership and experts. My report is over. Thank you.

Moderator: Far East Cable has done a lot of work in scientific research and development. This time they introduced the research and development of aluminum alloy cables and their applications. They are new products that they recommend in the cable industry.

The National Transmission and Distribution Technical Cooperation Network is a non-profit, self-disciplined service organization established by the China Electric Power Enterprise Association Science and Technology Development Service Center. It aims to practice government services, serve the industry, and serve the enterprise. In order to promote the scientific and technological innovation in the industry, Heli strives to build a platform for information communication, technology exchange, and technology collaboration between the power industry and the transmission and distribution manufacturers to jointly promote the improvement of the technology management level in the power industry and the competition for power transmission and transformation equipment. force.