Analysis of 3-Coil High Performance Inductive Link for Efficient Wireless Power Transmission

Wireless power transmission is widely used to recharge batteries, electric vehicles, and other small microelectronic devices. This work involves performance analysis of 2-coil and 3-coil inductive link wireless power transmission (WPT) system using newly devised mutual inductance formula. Power transfer efficiency (PTE), power delivered to the load (PDL) are used as performance parameters and figure of merit (FoM) is used as optimizing parameter to analyze 2-coil and 3-coil link WPT system. To make a good inductive link design, FoM must be considered which can help designers to make a balance between PTE and PDL at the same time. We have proposed that 3-coil link has much higher PTE, PDL and FoM compared to the 2-coil link and also showed how the optimizing parameter FoM changes with the increase of quality factor of primary coil for both inductive link WPT system. At ISM Band 13.56MHz carrier frequency and 12cm coupling distance, 2-coil and 3-coil inductive links have PTE of 11.68%, 48.32% respectively and PDL of 0.318W, 0.761W respectively. The FoM of 2-coil and 3-coil inductive links showed 0.149W, 2.03W respectively at 12cm coupling distance. These results have been verified through simulated data.