Voltage Evaluation Using PT-Symmetry in Wireless Power Transfer to Small Mobile Robot

Abstract

　We are studying a wireless power transfer to the small mobile robot using piezoelectric elements and electromagnets. The robot can move precisely in the µm scale and can be operated on a magnetic floor. However, the wireless power transfer to the robot equipped with a coil has a problem that the coupling coefficient changes as the robot moves, and the voltage on the secondary side fluctuates, preventing the robot from performing the required precision movement. Therefore, we are studying the suppression of voltage fluctuation transmitted to the secondary side by PT (Parity-Time) symmetry, which automatically operates at the resonance frequency regardless of the coupling coefficient. In this paper, we report the evaluation of secondary side voltage using LTspice.