## 5 Experimental Results
### HTLS (Dhaka ACCC/TW) Conductor  
Figure 8 shows the experimental results of the \(r_{AC}\) versus the temperature of the Dhaka ACCC/TW conductor. These results were obtained by heating the conductor at different current levels under power frequency supply up to nearly 190 \({}^{\circ}\)C with a high-current transformer. Note that the temperature coefficient of resistance \(\alpha\) plays a key role when analyzing a wide temperature range. For example, assuming \(r_{AC}=39.445\cdot(1+0.00436\cdot\Delta T)\) or \(r_{AC}=39.445\cdot(1+0.00390\cdot\Delta T)\) with \(\Delta T=180\)\({}^{\circ}\)C, in the first case it results in \(r_{AC}=70.401\), while in the second case it results in \(r_{AC}=67.135\), so the difference is \(\Delta r_{AC}\approx 5\%\). Figure 7: ACSR conductors. \(r_{ac}\) versus temperature measured at different current levels. **(a)** Three-layer ACSR conductor. **(b)** Two-layer ACSR conductor. The linear fit gives \(r_{AC}=201.52\cdot(1+0.00434\cdot\Delta T)\) [\(\mu\Omega/\mathrm{m}\)] with \(\Delta T=T-20\) [\({}^{\circ}\)C] and R\({}^{2}=0.9992\). **(c)** Single-layer ACSR conductor. \begin{table}
\begin{tabular}{l c c c} \hline \hline
**Description** & **Three-Layer** & **Two-Layer** & **Single-Layer** \\ \hline Designation & 550-AL1/71-ST1A & 135-AL1/22-ST1A & - \\ Number of Al strands & 54 (12/18/24) & 26 (10/16) & 10 \\ Number of steel wires & 7 (1/6) & 7 (1/6) & 7 (1/6) \\ Area of aluminum [mm\({}^{2}\)] & 549.7 & 134.9 & 51.87 \\ Area of steel [mm\({}^{2}\)] & 71.3 & 22 & 22 \\ Steel layer lay ratio [14] & 19 & 19 & 19 \\ Al layers lay ratios [14] & 15/13/11.5 & 14/11.5 & 14 \\ Diameter of Al strands [mm] & 3.6 & 2.57 & 2.57 \\ Diameter of steel wires [mm] & 3.6 & 2.0 & 2.0 \\ Measured outer diameter [mm] & 32.4 & 16.3 & 11.2 \\ Area of aluminum [mm\({}^{2}\)] & 549.7 & 134.9 & 51.87 \\ Area of steel [mm\({}^{2}\)] & 71.3 & 22.0 & 22.0 \\ Minim. conductivity of Al [32] & 61\% IACS & 61\% IACS & 61\% IACS \\ Min. conductivity of steel [33] & 8\% IACS & 8\% IACS & 8\% IACS \\  & 0.00434 (1080 A) & & 0.00462 (220 A) \\ Measured temperature coefficient of resistance, \(\alpha\) & 0.00459 (650 A) & 0.004435 & 0.00482 (145 A) \\ [\({}^{\circ}\)C\({}^{-1}\)] & 0.00425 (310 A) & & 0.00487 (75 A) \\ Measured \(r_{DC}\) at 20 \({}^{\circ}\)C [\(\mu\Omega/\)m] & 51.75 & 200.80 & 489.70 \\ Calculated \(r_{DC}\) at 20 \({}^{\circ}\)C [\(\mu\Omega/\)m] from (4) & 51.04 & 177.60 & 410.19 \\ Calculated \(r_{DC}\) at 20 \({}^{\circ}\)C [\(\mu\Omega/\)m] from (5) & 52.00 & 211.27 & 527.65 \\ Calculated \(r_{AC}\) at 20 \({}^{\circ}\)C [\(\mu\Omega/\)m] & 52.97 (1080 A) & & 178.40 & 412.04 \\  & 52.45 (650 A) & (all currents) & (all currents) \\  & 52.04 (310 A) & & & \\ Calculated \(r_{AC}\) at 20 \({}^{\circ}\)C [\(\mu\Omega/\)m] & 53.96 (1080 A) & 212.22 & 530.02 \\  & 53.48 (650 A) & (all currents) & (all currents) \\  & 53.02 (310 A) & (all currents) & (all currents) \\ Measured \(r_{AC}\) at 20 \({}^{\circ}\)C [\(\mu\Omega/\)m] & 53.10 (650 A) & 201.52 & 602.38 (220 A) \\  & 52.90 (310 A) & (all currents) & 535.12 (145 A) \\  & +1.78\% (1080 A) & & +31.60\% (220 A) \\  & +1.22\% (650 A) & +11.47\% & +21.31\% (145 A) \\  & +1.63\% (310 A) & & +17.39\% (75 A) \\  & \(-0.06\%\) (1080 A) & & +12.01\% (220 A) \\  & \(-0.72\%\) (650 A) & \(-5.31\%\) & +0.95\% (145 A) \\  & \(-0.25\%\) (310 A) & & \(-6.26\%\) (75 A) \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Main parameters of the analyzed ACSR conductors. Figure 8: Dhaka ACCC/TW conductor. \(r_{AC}\) versus temperature measured at different current levels. The linear fit gives \(r_{AC}=39.445\)-(1 + 0.00436\(\cdot\)\(\Delta\)7) [\(\mu\Omega/\)m] with \(\Delta\)T = \(T-20\) [\({}^{\circ}\)C] and R\({}^{2}\) = 0.9996. Table 4 summarizes the main parameters of the analyzed Dhaka ACCC/TW conductor.