Validation of the air-core inductor copper loss model for high-frequency power conversion applications

A simple analytical copper loss model for inductor is preferred for the design of low-loss and downsized circuits. Air-core inductors, which can avoid core losses and magnetic saturation, are suitable for power converters and wireless charging systems operating at high switching frequencies. This study derives a model for the calculation of the AC resistance of air-core solenoids, which includes the influence of skin and proximity effects on the basis of the measured frequency characteristics of impedance, and verifies the adequacy of this model in the high-frequency region. This study also discusses the optimal dimensional design of a single-layer solenoid to minimize copper loss for a given wire diameter and inductance value.