The production of carbon fiber composite core aluminum conductor mainly includes three steps: (1) preparation of carbon fiber precursor and carbon fiber yarn; (2) production of carbon fiber composite core; (3) production of carbon fiber aluminum conductor composite core. The carbon fiber composite core is involved in the field of organic materials, which is essentially different than the steel core of conventional conductor from the material to the production thereof.

GB/T 29324-2012 Fiber-Reinforced Resin Composite Core Rod for Overhead Conductor comprises the technical conditions regarding carbon fiber reinforced composite core and Q/GDW 1851 Carbon Fiber Composite Core Overhead Conductor comprises the technical conditions regarding carbon fiber composite core aluminum conductor, covering the current two mainstream products: heat-resistant aluminum alloy strand carbon fiber composite core aluminum conductor and soft aluminum strand carbon fiber composite core aluminum conductor.

Carbon fiber composite core aluminum conductor is made in developed countries such as the United States, and was applied as a test line in aslett, Texas as early as August 2004. Table 8.1 shows the statistics of some overseas applications of carbon fiber composite core aluminum conductors. There are 13 in the United States, of which one is a test line with a length of 1.06km. The number of 230kV lines is 2, 4.0km in total; the number of 161kV line is 1, length is 0.15km; the number of 138kV lines is 3, a total of 34.96km; the number of 115kV line is 1, length is 0.14km; and the number of 69kV lines is 2, 1.37km in total. The number of 34.5kV lines is 2, 35.05km in total and the number of 13.8kV lines is 1, length is 1km.

Stress–sag calculation of the conductor is an important link of line design. The highest running temperature of normal aluminum conductor steel reinforced is 70°C (select 80°C by East China Grid Corporation). Within the scope of such temperature, coefficient of linear expansion, elastic modulus, and other conductor parameters can be appropriately taken as the steady state values, thus, the applied stress–sag calculation software is designed based on the premise of constant conductor parameters.

Since the carbon fiber composite core aluminum conductor was put into application, it has been used and limited to capacity increase and transformation of short-distance lines. Although its technological superiority is exerted to a certain extent, its application scope is narrow and it fails to give play to social economical benefits in other fields of electric transmission line. Such situation is related to the exorbitant price of carbon fiber composite core aluminum conductor as well as its insufficiently mature construction, operation, and maintenance technologies. This section systematically analyzes the application scope and application models of carbon fiber composite core aluminum conductor and provides a basis for wider popularization and application of carbon fiber composite core aluminum conductor.

Connecting fittings (including strain clamp, straight connecting pipe, etc.) are key elements for connections between conductor and tower as well as conductor and conductor and the emphasis of conductor in the process of construction and maintenance. Strain clamps connect the conductor to the strain insulator string, and further connect it to the tower cross arm for fixing the conductor and bearing conductor tension as well as providing current-carrying capability. Strain clamps generally cover screw-type cable clamps, compression-type (pressure-type) strain clamps, and wedge-shaped strain clamps. Straight connecting pipe is used for conductor continuity or repatching, bearing conductor tension and providing current-carrying capability.

Carbon fiber composite core aluminum conductor detection items, methods, and equipment are different from that of conventional conductors. The detection thereof includes two parts. (1) Conventional parameter test. Carbon fiber composite core aluminum conductor should meet the requirements for mechanical and electrical performance of conventional conductor, that is, it should pass through a full set of conventional conductor type test items. (2) Artificial accelerated aging test and mechanical fatigue test. The carbon fiber composite core is an organic material, which is an innovation for both conductor manufacturing enterprises and application units. Its antiaging performance has drawn wide attention. State Grid Hebei Electric Power Research Institute (Hebei Electric Power Research Institute) has drawn lessons from organic composite insulators artificial accelerated aging test widely used in the grid and combined with the characteristics of the conductor to design and implement carbon fiber composite core aluminum conductor composite factor and an artificial accelerated aging test, thus laying a foundation for the safe operation and standard setting of carbon fiber composite core aluminum conductor. In addition, the threat of alternating/impact mechanical load on the material is much higher than the static mechanical load, which easily leads to mechanical fatigue damage and destruction of the material. Overhead lines operating environment varies widely, and mechanical fatigue damage due to breeze vibration, dancing, and other alternating mechanical stress is a problem that must be faced in conductor operation. Performance of carbon fiber composite core withstanding long-term mechanical fatigue is one of the issues that most users focus on. Northern China Electric Power Research Institute simulated various forms of mechanical vibration that may be encountered in the operation of carbon fiber composite core aluminum conductor, and implemented for the first time a carbon fiber composite core aluminum conductor’s 12×107 breeze vibration fatigue test, 3×107 splitting conductor vertical vibration fatigue test, horizontal vibration fatigue test, and torsional vibration fatigue test, giving a more comprehensive verification that the carbon fiber composite core aluminum conductor has mechanical fatigue resistance performance that is not less than or even better than ordinary aluminum conductor steel reinforced (ACSR), that is, considering from mechanical fatigue resistance, carbon fiber composite core aluminum conductor can operate safely for the long term on overhead transmission lines. In addition, some units have carried out research on the detection methods of composite core defects during the manufacture or construction of carbon fiber composite core aluminum conductors. For example, State Grid Smart Grid Research Institute has attempted detection of small composite core defects at the exit of the tensile machine using X-ray. In addition, the State Grid Liaoning Electric Power Supply Co., Ltd. has attempted to increase the microdefects in the composite core manufacturing process before the taking-up process, combined with the inspection of the composite core of inner and outer layers insulating voltage, hoping that defect-free carbon fiber composite core is produced and used for overhead transmission lines.

With the drastic increase of power load and the increasingly difficult choice of transmission corridors, the demand for improving the transmission power of corridors has become more and more urgent. The regular aluminum conductor steel reinforced (ACSR) can hardly meet the transmission demand. Given this background, a series of conductors that can be used for capacity expansion of transmission are developed both at home and abroad, including large-section ACSR and TACSR, ZTACIR, aluminum-based ceramic fibers, core heat-resistant aluminum alloy conductors, carbon fiber aluminum conductor composite core (ACCC), and other new conductors. Large-section ACSR is still part of the scope of ACSR, achieving the purpose of capacity expansion by just increasing the aluminum cross-section. Steel core heat-resistant aluminum alloy wire (TACSR) is made of aluminum added with zirconium, so as to improve the heat resistance of aluminum, with a wide operating temperature range. Invar core heat-resistant aluminum alloy wire (ZTACIR) is made of steel added with the appropriate proportion of nickel, so that the core wire has a lower linear expansion coefficient in a wide operating temperature range. Aluminum-based ceramic fiber core aluminum conductor (ACCR) and carbon fiber ACCC, collectively referred to as composite core aluminum conductors, are the conductors with the best overall performance at present. They not only have a wide operating temperature range and lower linear expansion coefficient, but also have a lower unit weight. ACCCs break the traditional conductor structure, which has many technical advantages, and are an important innovation in transmission conductors.