Control system proposal for detection of optimal operational point of series–series compensated wireless power transfer system

This article deals with analysis of the operational characteristics of series–series compensated WPT system, while the focus is given on the most suitable operational point considering system efficiency and power delivery. Initially, the investigation of transfer characteristics of the proposed WPT system is done through mathematical analysis. Results from mathematical analysis are showing certain specifics, which are useful for the optimization of the control system design. These specifics are related to the control variable, which for presented solution is a phase shift between current and voltage on the primary side of WPT system. Utilizing phase-locked loop, it is possible to achieve very high operational efficiencies together with peak power delivery even if radial or axial displacement applies. The proposed system is verified for certain frequency range, which is related to the parameters of the proposed WPT system. At the end of the paper, designed control system is verified on the experimental prototype of wireless charger at certain operational conditions (variations of axial displacements). Presented solution is characterized by its low complexity and high functionality if high power density of WPT systems is required.