High-Efficiency Laser Wireless Power Transfer System With Automatic Tracking for Smart Grids

Wireless power transfer for sensors in high-voltage direct current (HVDC) grids is crucial for smart grid, however stable and efficient energy delivery to moving targets remains a challenge. This paper presents a laser wireless power transfer (LWPT) system featuring high efficiency and automatically tracking fast-moving targets. The system employs coaxial optical configuration with beacon and high-power laser and compound-axis scanning strategy based on a microelectromechanical system (MEMS) fast steering mirror (FSM) and a voice-coil motor (VCM) FSM. In addition, a single-pixel scanning approach is adopted, significantly improving tracking speed and accuracy. This architecture enables simultaneous high-speed target tracking and stable power transmission. An eight-lobe photovoltaic (PV) array is designed to match the Gaussian beam profile while providing a sufficiently high output voltage, thereby significantly improving energy conversion efficiency. Experimental results demonstrate a power conversion efficiency (PCE) of 21–27%, representing an approximately threefold improvement compared with conventional PV array designs. The system achieves a maximum tracking speed of 75.4 cm/s and delivers a stable transmission power of 0.38 W at a distance of 10 m, with power fluctuations below 10 mW. The available LWPT distance is 5–17 meters. The proposed LWPT system provides a ‌feasible solution for powering mobile sensing nodes in smart grid applications.