results of NN, were not presented.

Similar to the previous studies mentioned above, studies regarding laser wireless charging systems mainly focus on improving the efficiency based on the material of the laser PV module and the introduction of research areas where the laser charging system is applicable. However, for the practical use of the laser charging system, studies regarding the control of the battery charging system using laser PV modules is required. There has been a lot of research on battery charging systems Similar to the previous studies mentioned above, studies regarding laser wireless charging systems mainly focus on improving the e fficiency based on the material of the laser PV module and the introduction of research areas where the laser charging system is applicable. However, for the practical use of the laser charging system, studies regarding the control of the battery charging system using laser PV modules is required. There has been a lot of research on battery charging systems using solar cell modules, but there are no research articles on the power converter design and control of

laser wireless charging systems using laser beams. Therefore, this paper deals with a controller design method based on the experimental results of laser PV module output characteristics for controlling the power converter of a laser wireless charging system. using solar cell modules, but there are no research articles on the power converter design and control of laser wireless charging systems using laser beams. Therefore, this paper deals with a controller design method based on the experimental results of laser PV module output characteristics for controlling the power converter of a laser wireless charging system. 

To extract the maximum power from a laser PV module, the operating point of the PV module must be controlled. To design a controller for controlling the operating point of the input source, a small-signal model of the PV module is required in the current source, voltage source, and maximum power point regions based on the laser output. First, we conducted an experiment to investigate voltage and current characteristics based on the laser output power of a laser PV module to generate the maximum power from a laser of a specific wavelength; subsequently, we derived the resistance values for small-signal fluctuations of voltage and current. After deriving the transfer function of the boost converter, including the small-signal resistance of the laser PV module, we designed a controller that can satisfy the dynamic performance in the entire operational area of the laser PV module. As described above, we herein present a method for designing the small-signal transfer function of a boost converter that reflects the small-signal characteristics of a laser PV module and a controller design method that can generate the maximum power from a PV module based on the MPPT algorithm. The method proposed herein was validated based on the simulation and experimental results of a 25-W-class boost converter prototype. To extract the maximum power from a laser PV module, the operating point of the PV module must be controlled. To design a controller for controlling the operating point of the input source, a small-signal model of the PV module is required in the current source, voltage source, and maximum power point regions based on the laser output. First, we conducted an experiment to investigate voltage and current characteristics based on the laser output power of a laser PV module to generate the maximum power from a laser of a specific wavelength; subsequently, we derived the resistance values for small-signal fluctuations of voltage and current. After deriving the transfer function of the boost converter, including the small-signal resistance of the laser PV module, we designed a controller that can satisfy the dynamic performance in the entire operational area of the laser PV module. As described above, we herein present a method for designing the small-signal transfer function of a boost converter that reflects the small-signal characteristics of a laser PV module and a controller design method that can generate the maximum power from a PV module based on the MPPT algorithm. The method proposed herein was validated based on the simulation and experimental results of a 25-W-class boost converter prototype. 

#### **2. Modeling and Controller Design of Laser Wireless Power Transmission System 2. Modeling and Controller Design of Laser Wireless Power Transmission System**

#### *2.1. Laser PV Module Characteristics 2.1. Laser PV Module Characteristics*

The PV module, which is the input source of the laser wireless charging system, has a configuration in which 16 PV cells are connected in series, as shown in Figure 2; it was manufactured by the Korea Advanced Nano Fabrication Center [5]. Using a high-power continuous fiber laser MFSC-200, laser beams with a wavelength of 1080 nm were irradiated onto the laser PV module at 2.478 and 2.874 <sup>W</sup>/cm<sup>2</sup> [9]. Figure 3 shows the voltage–current and voltage–power characteristics based on the laser beam power used in the experiment. The PV module, which is the input source of the laser wireless charging system, has a configuration in which 16 PV cells are connected in series, as shown in Figure 2; it was manufactured by the Korea Advanced Nano Fabrication Center [5]. Using a high-power continuous fiber laser MFSC-200, laser beams with a wavelength of 1080 nm were irradiated onto the laser PV module at 2.478 and 2.874 W/cm2 [9]. Figure 3 shows the voltage–current and voltage–power characteristics based on the laser beam power used in the experiment. 

**Figure 2.** Laser photovoltaic (PV) module with 16 cells connected in series. **Figure 2.** Laser photovoltaic (PV) module with 16 cells connected in series.

As shown in Figure 3, the PV module presents nonlinear output characteristics, in which the short-circuit current, open-circuit voltage, and location of the maximum power generation point varied according to the laser beam power. Since the maximum power generated from the PV module is the point at which the slope becomes 0 in the voltage–power curve, it can be confirmed that the maximum power generation point measured in the experiment is approximately 7 V. To quickly charge the UAV's battery from the PV module, the battery charging converter must include an MPPT algorithm to identify the maximum power point of the laser PV module as well as stably control the As shown in Figure 3, the PV module presents nonlinear output characteristics, in which the short-circuit current, open-circuit voltage, and location of the maximum power generation point varied according to the laser beam power. Since the maximum power generated from the PV module is the point at which the slope becomes 0 in the voltage–power curve, it can be confirmed that the maximum power generation point measured in the experiment is approximately 7 V. To quickly charge the UAV's battery from the PV module, the battery charging converter must include an MPPT algorithm to
