A Cost-Effective Magnetic Coupler for IPT Systems

Abstract

Inductive power transfer (IPT) technology enables wireless power transfer from one coil to another over an air gap via magnetic coupling. The structure, which magnetically couples the two coils, is the main part of every IPT system as it affects the overall efficiency, power transfer capacity, system cost, size, etc. This article proposes a simple and cost-effective magnetic coupling structure for IPT systems. In the proposed coupler, the primary uses parallel conductors to generate near-horizontal magnetic flux in the air gap, while the secondary uses an air-cored vertical coil to maximize the mutual flux linkage of the coupler. This article details the design procedure of the proposed coupler structure and compares it with three conventional designs to show that it offers better performance and lower cost. For further validation, a 2-kW IPT system prototype with the proposed magnetic coupler is built, and experimental and simulated results under different conditions are presented to demonstrate its effectiveness. The system efficiencies range from 75.6% to 83.4% for output powers between 0.82 and 2.18 kW. Additionally, simulations illustrate how its performance can be further enhanced.