A combined transmitting coil design for high efficiency WPT of endoscopic capsule

This paper presents a combined wireless power transmitting coil designed for endoscopic capsule. In the design, a group of vertically segmented transmitting coils are combined to work. According to the position of the capsule, one, two or three segmented transmitting coils will be selected to work, which makes the capsule closer to the center of the combined transmitting coils. The mechanism ensures high power transfer efficiency and good homogeneity of the energy distribution. This paper also gives the theoretical expression about how to combine the segmented transmitting coils to work together with the highest performances. The experiments show that the minimum and average AC-AC transfer efficiency are 7.53% and 12.7% respectively.