IPT design with optimal use of spiral rectangular coils for wireless charging of e-tricycle scooters

Abstract

One of the most important research topics in wireless charging is the development of optimal coil pads. In this paper, an optimal inductive power transfer (IPT) system that meets the wireless charging requirements of an e-tricycle scooter has been designed. For an effective IPT design, the parameters such as resistance and inductance of the coil that affect the power transfer efficiency must be calculated correctly. The resistance and inductance calculation per winding has been taken into account instead of using the average winding dimensions of the primary and secondary pads due to the small size of the coils. The resistance and self-inductances of air-core spiral rectangular coils, and mutual inductance between them for a distance of 100 mm have been calculated with high accuracy using this method. Critical magnetic coupling factor, primary and secondary quality factors and maximum operating frequency have been considered as system stability criteria. The optimal IPT system that meets the criteria and uses minimum copper has been experimentally performed. The performance of the optimal IPT has been investigated firstly at equivalent AC load, and then resistive load by connecting the active rectifier to the secondary-side. The efficiency of DC to DC has been achieved as 89.2% in approximate load conditions.

Keywords

• Inductive power transfer
• Optimal coil design
• Wireless charging
• Active rectifier