System Level Requirement Analysis of Beam Alignment and Shaping for Optical Wireless Power Transmission System by Semi–Empirical Simulation

Abstract

Since optical wireless power transmission (OWPT) transmits power by light, which has a narrow diffraction angle feature, it is a strong candidate for wireless power transmission systems supporting long ranges. To develop a realistic operational OWPT system, clarification of system level requirements is essential. In this study, to fill a gap between the concept/initial demonstration and an operational system, the required conditions were analyzed regarding the effects of beam alignment and shaping on the power generation ratio which is a system level efficiency factor with extension from the formerly reported one-dimensional analysis to three-dimensional to include errors in all degrees of freedom is presented. This extension is regarded as an indispensable methodology to evaluate the system level performance of general OWPT systems. Numerical requirements for beam alignment and shaping are derived for both non-cooperative and cooperative OWPT. In non-cooperative OWPT, the direction of the solar cell module is fixed, and the transmitter aligns its beam with the module. In cooperative OWPT, the module and transmitter mutually align in the same direction. Though the cooperative OWPT is more restrictive than the non-cooperative one, its advantages were clarified.