## 3 Simulation Results and Experimental Validation
### Simulation Results and Experimental Verification  
The capacitor charging voltage of the impulse current generator, the voltage amplitude of the surge arrester, and the current amplitude of each column of the surge arrester are recorded in Table 4. The coefficients of the current distribution corresponding to each group of tests are also calculated. Due to the difference in V-I characteristics of each column, the current through each column is uneven. The current distribution is plotted as a function of the amplitude of the surge arrester in Figure 9. The current of columns 1, 2, and 3 increases sequentially. With the current increase, the coefficient of the current distribution \(\beta\) decreases. When the test voltage is applied to the parallel varistor columns, column 1 has the smallest current, while column 3 has the largest current. When the capacitive charge voltage of the impulse current generator is 90-195 kV, the single-column current is between 154 and 1270 A. The residual voltage range of the arrester is 82-105 kV. When the capacitor charging voltage is 90 kV, the total current amplitude flowing through the arrester is 484 A, and the residual voltage of the arrester is 82 kV. The currents of column 1, column 2, and column 3 are 154 A, 162 A, and 168 A respectively. The non-uniform coefficient of the current distribution is the maximum 1.041. When the capacitor charging voltage is 375 kV, the total current amplitude through the arrester is 9280 A, and the residual voltage of the arrester is 131 kV. The currents of columns 1, 2, and 3 are 3040 A, 3100 A, and 3140 A, respectively, and the non-uniform coefficient of current distribution is the minimum 1.015. \begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Capacitor Charging**} & \multirow{2}{*}{**Voltage Amplitude of**} & \multicolumn{3}{c}{**Current**} \\  & & **Amplitude/A** & **The Coefficient of the** \\
**Voltage/kV** & & **the Surge Arrester/kV** & **1** & **2** & **3** \\ \hline
90 & 82 & 154 & 162 & 168 & 1.041 \\
120 & 87 & 314 & 320 & 334 & 1.035 \\
135 & 91 & 488 & 500 & 516 & 1.029 \\
150 & 95 & 680 & 698 & 718 & 1.028 \\
165 & 98 & 868 & 872 & 904 & 1.026 \\
180 & 102 & 1040 & 1060 & 1090 & 1.025 \\
195 & 105 & 1220 & 1240 & 1270 & 1.021 \\
210 & 110 & 1420 & 1440 & 1480 & 1.023 \\
225 & 112 & 1610 & 1660 & 1690 & 1.022 \\
255 & 119 & 1980 & 2040 & 2080 & 1.023 \\
285 & 125 & 2360 & 2440 & 2480 & 1.022 \\
315 & 128 & 2540 & 2560 & 2620 & 1.018 \\
360 & 130 & 2900 & 2920 & 3000 & 1.020 \\
375 & 131 & 3040 & 3100 & 3140 & 1.015 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: The data of the current distribution experiment. Figure 8: Number schematic diagram. Figure 10 compares the three-column ZnO varistors' simulation and experiment comparison results. It is a comparison diagram of the temperature rise process and temperature drop process of the ZnO varistors. Figure 11 illustrates the simulation and experiment comparison results of the three-column spacers. It is a comparison diagram of the temperature rise process and temperature drop process of the spacers. Lines and dots are used to represent the simulation and experiment results. The three colors correspond to the situation on the three columns. From the simulation results of the ZnO varistors, the maximum temperature of column 1 is 76.60 \({}^{\circ}\)C, the maximum temperature of column 2 is 63.90 \({}^{\circ}\)C, and the maximum temperature of column 3 is 80.50 \({}^{\circ}\)C. From the experiment results of the ZnO varistors, the maximum temperature of column 1 is 74.39 \({}^{\circ}\)C, the maximum temperature of column 2 is 62.41 \({}^{\circ}\)C, and the maximum temperature of column 3 is 77.30 \({}^{\circ}\)C. The difference between the experimental results and the simulation results is within 3.9%. This is mainly due to imprecise simulation settings and experimental measurements. Figure 10: Temperature comparison diagrams of the simulation and experiment between each column ZnO varistor. (**a**) is the temperature rise process of the ZnO varistors.