Design, analysis and application of wireless electrical energy conversion

Abstract

Recently, the magnetic resonant coupling (MRC) based wireless power transfer (WPT) has been investigated extensively since it can realize the cordless immigration of energy over a long transfer distance. With the distinctive characteristics of high reliability, security, flexibility and convenience, the emerging WPT can be developed to achieve wireless charging for electric vehicles, portable electronics and household appliances. From the perspective of energy conversion, the possibility of the WPT technique can be further stretched to achieve wireless energy conversion from electrical energy to several other forms of energy. Therefore, this study works on the design and analysis of the wireless electrical energy conversion, which mainly includes wireless heating, wireless lighting and wireless charging. In terms of wireless heating, firstly, a flexible wireless heating system is proposed and implemented by utilizing multiple resonant coils and the MRC mechanism to significantly enhance the tolerance of deviation between the cooktop and the pan. Subsequently, a wireless heating system with more uniformed temperature distributions is developed by employing both the primary and resonant coils to heat the workpiece concurrently. For instance, the double resonant coils are concentrically arranged in a planar cooktop to achieve homogeneous wireless heating for flat-bottom pans, and the frustum coil is newly designed for evenly heating convex-bottom woks so as to achieve all-in-one wireless heating. Next, the concept of all-utensil wireless heating, namely, the effective heating of workpieces made of conductive ferromagnetic material, conductive non-ferromagnetic material and non-conductive non-ferromagnetic material, is proposed by adopting the sandwiched-coil structure and pulse density modulation. In terms of wireless lighting, the high-order compensated wireless lighting systems with corresponding dimming controls are presented. In particular, the LCC-LC compensated WPT is built for wireless metal halide lighting with phase shift control and the S-CLC compensated WPT is established for wireless low-pressure sodium lighting with pulse frequency modulation. Secondly, the general analysis of the multi-coil direct-drive wireless high-intensity discharge lamp is conducted by properly selecting the different number of coils as well as the compensation topologies. It should be noted the brand-new wireless lighting is more suitable for modern lighting system since it can readily eliminate the bulky magnetic ballast or complicated electronic ballast with no maintenance and no risk of electrocution under harsh weather conditions. In terms of wireless charging, firstly, the wireless charging with coil position detection using tunneling magnetoresistive (TMR) sensors is discussed. Specifically, a circular sensor array assembled by 12 TMR sensors is located in the transmitter side to accurately detect the position of the invisible on-implant receiver by directly measuring the variation of the magnetic field. Secondly, the double-3D-coil structure with the optimized coil direction is proposed to achieve the dynamic wireless charging for the drone, namely, the fly-and-charge. Finally, to validate the feasibility and performance of the aforementioned wireless electrical energy conversion systems, the theoretical analyses, computational simulations and experimental prototypes are established and provided to achieve the in-depth discussions and verifications of the proposed wireless heating, wireless lighting and wireless charging systems.