Effects of Obstacle Sizes on Wireless Power Transfer via Magnetic Resonance Coupling

In this work, a comprehensive study on effects of obstacle sizes on WPT systems via magnetic resonance coupling is conducted by virtue of full-wave electromagnetic solutions. Five types of obstacles, i.e. Cu obstacles, ABS obstacles, earth obstacles, glass obstacles and sea-water obstacles, are discussed. It is shown that the sizes of ABS and glass obstacles have little effects on the efficiencies and resonant frequencies of WPT systems via magnetic resonance coupling. With the increasing sizes of earth obstacles, Cu obstacles and sea-water obstacles, the efficiencies of WPT systems will decrease and resonant frequencies will vary. The efficiencies will reduce more quickly with the increase of side lengths than the increase of thicknesses of Cu obstacles. The efficiencies always decrease dramatically with the increase of side lengths and thicknesses of sea-water obstacles. The results are also verified by experiments.