A M-Hz High Distance–Diameter Ratio IPT Systems Based on Multi-Segment Series Compensation

With the rapid development of the Internet of Things (IoT), demand for flexible, lightweight, and miniaturized power supply solutions is growing. In inductive power transfer (IPT) systems, however, increasing operating frequency and using tightly wound coils exacerbate the effects of parasitic capacitance, leading to additional losses. While increasing the turn-to-turn spacing can mitigate this effect, it significantly reduces mutual inductance and limits long-distance transmission capability under the same volume constraints. To address these challenges, a distributed parameter circuit model incorporating segmental inductance, distributed capacitance and equivalent resistance is established to clarify the mechanism of parasitic capacitance loss. Building upon this, a multi-layer-multi-segment compensation strategy designed for small-size and high-frequency applications is proposed, effectively suppressing the current flowing through parasitic capacitances, thereby reducing the associated dielectric loss and improving the transmission efficiency of the system. A 100 W prototype is implemented with couplers of 100 mm diameter using multi-layer tightly wound coils. At a transmission distance of 200 mm, the system delivers 47 W to a 25 Ω load with an efficiency of 38.9%.