# Advanced Composite Materials: A Panacea for Improved Electricity Transmission
## 2 Strength and Challenges of Transmission Conductors  
An electrical conductor is a substance that permits electric current to flow through it, as contrasted by an electrical insulator that obstructs the flow of electric current across it. Good electrical conductors are metals with high conductivity and low resistance. Electrical conductors in the conduction band enable electrons to move freely between atoms of a substance. Metals, metal alloys, electrolytes, and non-metals including graphite and conductive polymers have all been proven to be useful electrical conductors in their raw states [12; 28]. However, these materials may be improved and utilized as power transmission conductors for low- and high-voltage transmissions [29]. Aluminum conductor steel reinforced (ACSR) and all aluminum alloy conductor (AAAC) conductors are the most prevalent and widely used conventional transmission conductors on the market [30; 31]. They are meant to work at maximum temperatures of 85 and 95 degrees Celsius, respectively, according to [PERSON] [27]. The thermal limitations for the conductors are established by the fact that they are annealed as a consequence of subsequent heating [32]. The ACSR conductor is a high-capacity, high-strength conductor that is often used in the construction of overhead power transmission lines. It is made up of layers of aluminum strands wound helically around a galvanized steel core. According to studies, the CTE of steel and aluminum materials are between 11.5 \(\times\) 10\({}^{-6}\) and 23 \(\times\) 10\({}^{-6}\) degrees Celsius, respectively [11; 31]. At temperatures above 93 degrees Celsius, the aluminum material in the conventional ACSR conductor anneals and loses its strength, rendering it unsuitable for use [27]. The density of the steel in the ACSR conductor is 7.78 mg/m\({}^{3}\). As a result, the performance of the conductor is restricted by temperature and density. The high coefficient of thermal expansion of ACSR renders the conductor vulnerable to corrosion and excessive sag. So, the high density, thermal limitation, and high cost of galvanized steel are major restrictions in the conductor [33]. However, these issues may be solved by using improved nanotechnology to develop robust and smart conductor materials. The AAAC conductor is made of an aluminum-magnesium-silicon alloy that has a high electrical conductivity, high corrosion resistance, high strength-to-weight ratio, and enhanced mechanical properties, thanks to the presence of magnesium silicide [34]. AAAC conductors are frequently used for power transmission in low voltage transmission lines. The thermal conductivity value is the major problem in this conductor. There is a second phase known as impurities, which ravages these aluminum-based conductors. The impurities can be detected with transmission electron microscope (TEM) [35]. Figure 3 shows pictures of (a) ACSR and (b) AAA conductors, illustrating their various characteristics and designs. High-temperature low-sag (HTLS) conductors are another set of conductors that have been improved and proven to be more efficient in transmission networks than the conventional conductors. The HTLS conductors, which were created primarily to increase the ampacity in power transmission grid, exhibit reduced sag and withstand greater temperatures and ice loads. They have numerous significant benefits over the ACSR and AAAC conductors. The following are some of the advantages: (i) They operate at higher temperatures, typically between 100 and 250 degrees Celsius. (ii) Their installation and operation on existing grids are usually very safe. (iii) They can be easily installed on existing transmission lines without requiring much structural modification, saving time and money. (iv) They are more conductive than the ACSR and AAAC. (v) They have less fatigue-related issues. (vi) They have lower density than the conventional conductors [36; 37; 38].