Experiment of magnetic resonant coupling three-phase wireless power transfer

Three-phase electric power (three-phase) is an essential technology for high power electric wiring. Three-phase, however, has not been attached to wireless power transfer (WPT). The authors suggest that characteristics of three-phase system are suitable for high power WPT with magnetic resonant coupling. Three-phase WPT has three times as large capacity as conventional single-phase WPT has. The power capacity of three-phase system is expected up to 10 kW or more in large air gap with high transfer efficiency. Three-phase system has two other advantages, relatively simpler circuit, and very small power ripples compared to single-phase system. These are potential advantage of three-phase system. Some suitable applications, on the other hand, are expected for three-phase system. One example of suitable application for three-phase WPT is power transfer to rotating equipment, because three-phase has rotation symmetry, thus the authors construct rotating resonators. The experiment, at first, proves feasibility of three-phase WPT. Then the rotating experiment proves three-phase WPT can be attached to rotating equipments. These results of experiments are compared to theoretical values which are calculated by equivalent circuit formulas. The formulas are modified from single-phase WPT equivalent circuit. The formulas can also derive optimal load resistance value for the highest transfer efficiency. The formulas suggest that the optimal resistance value depends on the rotating angle of resonators.