A Cross-Double D Coupler for Improved Tolerance to Misalignment Conditions

Wireless Inductive Power Transfer (IPT) systems are rapidly evolving in applications such as wireless charging of biomedical implants and electric vehicles (EVs). Misalignment between coils can significantly impact power transfer efficiency in non-autonomous systems. Most of the earlier research focused on power electronics, with limited emphasis on optimizing electromagnetic couplers. This paper introduces a new concept of Cross Double-D (CDD) electromagnetic coupler to improve power transfer even under misalignment conditions. The proposed model is derived from fundamental electromagnetic principles, simulated using ANSYS FEA software, and validated through experiments. The mathematical model demonstrates a design accuracy of 98% in predicting self-inductance. The CDD electromagnetic coupler is shown to have ~5 times better tolerance to misalignment than the typical circular coupler while retaining 67% of maximum power at 40 mm misalignment compared to just 24% for the circular design. Furthermore, the CDD coupler has a relatively high-power transfer efficiency of 88%.