Modular Wireless Power Transmission for Photovoltaic Subpanel System

Abstract

A modular wireless power transmission (WPT) Photovoltaic (PV) subpanel system is proposed. The PV system may contain multiple PV subpanels, and each subpanel is integrated with an individual DC/DC converter connected to a full bridge inverter and to a WPT LC resonant tank. The PV units can be placed on a wireless charging mat, and each WPT unit can be independently designed without affecting other units’ performance. However, because of the rugged outdoor environment, it is difficult to precisely know various circuit parameters, airgaps, or other influential variables that need to be matched or optimized for the WPT. Therefore, two separate power point tracking algorithms are implemented. The first (traditional) maximum power point tracking (MPPT) is used to maintain the solar panel at its highest efficiency point. The second frequency power point tracker is used to adjust the operating frequency of the inverter to match the resonant frequency of the WPT system to ensure the maximum efficiency transfer. Preliminary experimental results are provided to verify the robustness of the WPT system features and the control strategies.