Comparative Analysis of a Center-Tapped Receiver in a Lightweight Powertrain-Integrated IPT Charger for UAS

Inductive power transfer (IPT) is a promising solution for autonomous unmanned aerial systems (UAS), but stringent size and weight constraints demand ultra-compact receiver designs. This work proposes a compensation-less center-tapped (CT) receiver for high-coupling IPT systems integrated into a reconfigurable drone powertrain. The system operates as a two-stage IPT architecture, combining a CT rectifier with a powertrain-integrated, two-phase interleaved synchronous buck converter during charging mode. This paper derives a differential–equation-based model that describes the operation of a CT rectifier in an LCC-None IPT system. Moreover, the model quantifies the effect of system parameters and parasitic components on diode voltage overshoot. A multi-objective optimization (MOO) framework maximizes efficiency and gravimetric power density while minimizing diode voltage overshoot. Two methods are evaluated to suppress diode voltage overshoot: (1) a passive snubber circuit and (2) a clamping capacitor. An optimum design is selected and prototyped, delivering an output power of 1.74kW to a 48-V battery. The system reaches a peak efficiency of 89.5% with a total added weight of 372.1 g. This represents a practical power-to-weight ratio of 4.7 W/g—the highest gravimetric power density reported so far for this UAS IPT charging level.