## 4 Experimental Verification  
To prove the effectiveness of proposed method effectively and accurately, two short-circuit experiments at different Chinese HSR lines were performed. The first experiment was carried out in the feeding arm of Jiangyou substation on the Chengdu-Chongqing HSR line on 11 October 2015. The second short-circuit experiment was carried out in the feeding arm of Qinglinkou substation on the Xian-Chengdu HSR line on 12 July 2017. The cross section and parameters of traction network conductors in the experiments are shown in Figure 2 and Table 2. The numbers of all the loop circuits in the experiments are listed in Table 1. In the two short-circuit experiments, flexible copper stranded conductor was used to short-circuit the rail and the catenary. Figures 6 and 7 depict the circuit diagram and scene diagram of two short-circuit experiments. According to Figure 6, whether for the first short-circuit experiment or the second short-circuit experiment, switches A1, A2, A4, A6, A13, A14, A17 and A18 are closed and the other switches are opened to simulate the standard 2 \(\times\) 25-kV AT double track power supply mode. The effective values of all the measured currents are shown in Table 3. In addition, the low-voltage side bus voltages of the traction substation \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Cable and Its Horizontal and** & **Type** & **DC Resistance** & **Calculated** \\
**Vertical Coordination (cm)** & **Type** & **(\(\Omega\)/km)** & **Radius (cm)** \\ \hline JW1 (0, 530), JW2 (460, 530) & CTS-150 & 0.15967 & 0.72 \\ \hline CW1 (0, 690), CW2 (460, 690) & JTMH-120 & 0.242 & 0.7 \\ \hline R1 (\(-\)71.75, 0), R2 (71.75, 0), & 60 kg & 0.135 & 1.279 \\ R3 (388.25, 0), R4 (531.75, 0) & & & \\ \hline PW1 (\(-\)340, 690), PW2 (800, 690) & LBJLJ-120/20 & 0.2382 & 0.763 \\ \hline EW1 (\(-\)400, \(-\)246), EW2 (860, \(-\)246) & DH-70 & 0.312 & 0.437 \\ \hline FW1 (\(-\)410, 680), FW2 (870, 680) & LBGLJ-240/30 & 0.1181 & 1.08 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Parameters of all the conductor wires in the HSR line from Chengdu to Chongqing. and the total currents of the transmission conductors are, respectively, collected at the secondary side of the traction transformer and current transformer in the position of switch A1. According to the collection results, the measured integrated impedance can be obtained. Based on the proposed deduction method, the current distribution coefficients of conductors in the short-circuit experiments are calculated in Table 4, after the initial current distribution is continuously adjusted to satisfy the constraint condition of real circuit voltages as much as possible. Compared with existing analysis results of current distribution in the traction network ([21; 29]), the deduced results in Table 4 are reasonable. Furthermore, according to Table 4, the deduced current distribution coefficients of T, N and F are 0.6235, 0.2138 and 0.3765, respectively. According to Table 3, the measured current distribution coefficients of T, N and F in the first short-circuit experiment are 0.6304 (\(I_{T}/I\)), 0.1985 (\(I_{G}/I\)) and 0.3673(\(I_{F}/I\)), respectively, and the measured current distribution coefficients of T, N and F in the second short-circuit experiment are 0.6233 (\(I_{T}/I\)), 0.2180 (\(I_{G}/I\)) and 0.4055(\(I_{F}/I\)), respectively. The comparison between the measured current distribution coefficients and the deduced current distribution coefficients is demonstrated in Figure 8. Obviously, the deduced results are very close to the measured results. Figure 8: Comparison between measurement results and results of deduction for the current distribution. Figure 6: Circuit diagrams of the two short-circuit experiments. Figure 7: Scene diagrams of the short-circuit experiments.