## 5 Experimental  
To verify the above theory, a confirmatory experimental prototype of the proposed system was constructed. The hardware of the prototype is shown in Figure 11. It consists of a DC voltage source, a compensation inductor \(L_{1}\), compensation capacitors \(C_{1}\) and \(C_{2}\), an  
Figure 10: Program diagram for mode selection. Figure 9: Switching strategy for the proposed LC/S compensated IPT system. LCT, an HFI, a rectifier, a resistive load, and an oscilloscope. Referring to the LCT structural parameters in Table 2, the coil used for the experiment is wound, as illustrated in Figure 12. As shown in Figure 12, the transmitting coil \(L_{\text{P}}\) is placed just above the series compensation inductor \(L_{1}\), ensuring the compactness of the whole IPT system. In addition, the coupling mutual inductances between \(L_{\text{P}}\) and \(L_{1}\) and between \(L_{\text{s}}\) and \(L_{1}\) are both zero as measured by the LCR meter, which verifies the theoretical analysis of the decoupling coil in Section 3. The measured values for each piece of hardware are shown in Table 4.  
Figure 13 displays the waveforms of \(\mathbf{U_{\text{in}}}\), \(\mathbf{I_{\text{1}}}\), \(I_{\text{out}}\) and \(U_{\text{out}}\) at an operating frequency of 90 kHz when the loads are 10 \(\Omega\) and 15 \(\Omega\), respectively. According to Figure 13, \(\mathbf{U_{\text{in}}}\) and \(\mathbf{I_{\text{1}}}\) are always in phase under different loads. In addition, \(I_{\text{out}}\) remains at 2.5 A, which means that ZPA operation and CCO are realized. Figure 14 displays the experimental waveforms of \(\mathbf{U_{\text{in}}}\), \(\mathbf{I_{\text{1}}}\), \(I_{\text{out}}\) and \(U_{\text{out}}\) at an operating frequency of 72 kHz when the loads are 25 \(\Omega\) and 50 \(\Omega\), respectively. Consistent with the above analysis, according to Figure 14, \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Parameters** & **Value** & **Parameters** & **Value** \\ \hline \(f_{\text{cc}}\) & 90 kHz & \(C_{1}\) & 107.73 nF \\ \(f_{\text{cv}}\) & 72 kHz & \(C_{2}\) & 32.61 nF \\ \(L_{1}\) & 80.63 uH & \(R_{\text{P}}\) & 0.12 \(\Omega\) \\ \(L_{\text{P}}\) & 45.35 uH & \(R_{\text{s}}\) & 0.08 \(\Omega\) \\ \(L_{\text{s}}\) & 138.03 uH & \(R_{\text{m}}\) & 0.16 \(\Omega\) \\ \(M\) & 26.23 uH & \(I_{\text{out}}\) & 2.5 A \\ \(U_{\text{d}}\) & 82 V & \(U_{\text{out}}\) & 45 V \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Measured values of specific parameters in the proposed LC/S compensated IPT system. Figure 11: Experimental setup of the proposed LC/S compensated IPT system. Figure 12: Experimental setup of the proposed LC/S compensated IPT system: (**a**) transmitting pad, (**b**) receiving pad. when the operating frequency is 72 kHz, the system can achieve CVO with ZPA operation. In summary, it is verified by experiments that the LC/S compensated IPT system proposed in this study can realize CCO and CVO characteristics at fixed ZPA operating frequency points. Therefore, the charging requirements of the battery are satisfied. The energy transmission efficiency curve of the system during the whole charging process is displayed in Figure 15. In CC charging mode, the energy transfer efficiency of the system increases rapidly from 89.2% to 92.8%. When the equivalent load rises to 18 \(\Omega\), the operating frequency of the system is switched from \(\omega_{\rm cc}\) to \(\omega_{\rm cv}\) for CV charging mode. In CV charging mode, the peak energy transfer efficiency of the system is 94.4%. In addition, the power transfer efficiency of the system stays at a relatively high level throughout the charging process, which ensures high efficiency of the proposed LC/S compensated IPT system. Figure 14: Experimental waveforms of the IPT system in CV charging mode. (**a**) \(R_{\rm L}=25\)\(\Omega\); (**b**) \(R_{\rm L}=50\)\(\Omega\). Figure 15: The efficiency of the proposed LC/S compensated IPT system throughout the charging process.