**Figure 19.** Prototype boost converter configuration.

*Electronics* **2020**, *9*, 1745 In this experiment, because the battery did not reach the full-charge voltage set at 24.5 V, it was operated in the MPPT mode; furthermore, it was confirmed that the battery was charging while moving to the maximum power point of the PV module. Figure 21 shows the enlarged waveform of the converter performing the MPPT operation. The voltage of the laser PV module, indicated by the yellow CH1 waveform, was tracking the maximum power point by changing the operating point at every MPPT sampling period with a 2 s period. In this experiment, because the battery did not reach the full-charge voltage set at 24.5 V, it was operated in the MPPT mode; furthermore, it was confirmed that the battery was charging while moving to the maximum power point of the PV module. Figure 21 shows the enlarged waveform of the converter performing the MPPT operation. The voltage of the laser PV module, indicated by the yellow CH1 waveform, was tracking the maximum power point by changing the operating point at every MPPT sampling period with a 2 s period. 

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**Figure 20.** Experimental result of maximum power point tracking (MPPT) control of laser PV module for battery charging. **Figure 20.** Experimental result of maximum power point tracking (MPPT) control of laser PV module for battery charging. **Figure 20.** Experimental result of maximum power point tracking (MPPT) control of laser PV module for battery charging. 

**Figure 21.** Enlarged waveform of MPPT control operation. **Figure 21.** Enlarged waveform of MPPT control operation. **Figure 21.** Enlarged waveform of MPPT control operation.

**4. Conclusions**  Herein, a controller design method that reflects the small-signal voltage and current characteristics of a laser PV module for a wireless power system using a laser beam was presented. The laser PV module was fabricated to generate the maximum energy from a laser light source of a specific wavelength (1080 nm in the case of the module used in this study). From the PV module **4. Conclusions**  Herein, a controller design method that reflects the small-signal voltage and current characteristics of a laser PV module for a wireless power system using a laser beam was presented. The laser PV module was fabricated to generate the maximum energy from a laser light source of a specific wavelength (1080 nm in the case of the module used in this study). From the PV module In this experiment, because the battery did not reach the full-charge voltage set at 24.5 V, it was operated in the MPPT mode; furthermore, it was confirmed that the battery was charging while moving to the maximum power point of the PV module. Figure 21 shows the enlarged waveform of the converter performing the MPPT operation. The voltage of the laser PV module, indicated by the yellow CH1 waveform, was tracking the maximum power point by changing the operating point at every MPPT sampling period witha2s period.
