## 4 Experiment Verification
As shown, \(U_{AB}\) and \(U_{b}\) remained constant, while \(I_{AB}\) and \(I_{b}\) dynamically changed with respect to the load. As shown at the bottom of Figures 17 and 18, in the CC/CV charging modes, \(I_{AB}\) was in the same phase as \(U_{AB}\), where \(I_{AB}\) lagged behind \(U_{AB}\). This was conducive to achieving ZVS and reducing the HFI loss. When the charging voltage gradually reaches the 120 V battery threshold voltage, it is necessary to observe the transient response process. Figure 18 presents the waveforms of \(U_{AB}\), \(I_{AB}\), \(U_{b}\), and \(I_{b}\) in the process of turning off \(S_{1}\) and \(S_{2}\). As shown, compared with the case before the  
Figure 16: Experimental waves of \(U_{AB}\), \(I_{AB}\), \(U_{b}\), and \(I_{b}\) in the CC mode. Figure 17: Experimental waves of \(U_{AB}\), \(I_{AB}\), \(U_{b}\), and \(I_{b}\) in the CV mode. mode switching, the charging voltage and current after the mode switching essentially remained constant, indicating that the CC charging could be smoothly converted into the CV charging mode. Moreover, the charging-mode conversion takes a short time and has almost no effect on the charging process. The experimental results prove the proposed IPT charger's effectiveness. Figure 19 presents the power-loss proportion of each part of the proposed charger. Power loss measured at the switching point (\(R_{\text{L}}=10.2\)\(\Omega\)) from the CC to CV mode mainly included HFI, compensation of the inductor and capacitor, LCT, and rectifier losses. Each component's power loss can be deduced through calculating the product of the parasitic resistance and its resonant current. As shown in Figure 19, the losses of the inverter, rectifier, and LCT accounted for the majority of the overall system losses, indicating that their rational design can significantly improve the system's efficiency. Simultaneously, it can be observed that after mode switching, the resonant compensation topology is switched from LCC-LCC to LCC-S, and the current flowing through each component changes, leading to differences in power loss. After switching the compensated topology, the capacitor power loss in the CV mode was reduced by 1.9%. The experimental results for the system efficiency measured by the power analyzer are presented in Figure 20. The highest system efficiency in the CC mode was around 92.2%, and that in the CV mode was around 92.3%. Therefore, the proposed IPT systems are effective in improving the system's efficiency. To more intuitively show the proposed system's performance, we conducted a comparative analysis of other methods as shown in Table 3. Firstly, the proposed hybrid compensation IPT system was not limited by LCT, outperforming the methods mentioned in [6; 14; 19; 27; 35]. Secondly, secondary-side control was adopted. The configuration of  
Figure 19: The proposed hybrid topology’s measured power-loss distribution at \(R_{\text{L}}=10.2\)\(\Omega\): (**a**) CC mode; (**b**) CV mode. Figure 18: Transient waves of \(U_{AB}\), \(I_{AB}\), \(U_{b}\), and \(I_{b}\) from the CC charging mode to the CV charging mode. the wireless communication link can be omitted, which has certain advantages compared to [6; 14; 26; 27; 36]. Thirdly, compared with [14], we can observe that the proposed IPT charger avoids the additional DC/DC converter at both sides, effectively reducing the IPT system's cost. Fourthly, the proposed compensation capacitor, \(C_{f2}\), on the secondary side of the IPT charger can be fully utilized, which is an advantage that other control methods do not have. Finally, compared with these control methods, the experimental efficiency was relatively high. In short, the proposed control CC/CV IPT charger scheme adopts secondary-side control without compromising design freedom, avoids the configuration of wireless communication link, does not require additional DC/DC converter and compensation capacitors, and has a relatively simple control logic, reducing the proposed IPT charger's cost and complexity.