Induced Voltage Estimation From Class EF Switching Harmonics in HF-IPT Systems

One of the advantages high-frequency inductive power transfer systems is high tolerance to misalignment and large air-gaps. However, inherently magnetic field volumes can lead coupling additional foreign objects with primary, causing possible detuning system heating objects. These conditions local environment load transmitter, which changes induced voltage on primary side. Unfortunately, not directly measurable in an operating transmitter most straightforward way calculating this variable, through a measurement coil current voltage, cause significant decrease quality factor reduces performance. An integrated solution capable estimating other less invasive measurements needed ensure safety operation object detection. Knowledge also be used correct tuning mismatches where both sides link are active (i.e., synchronous rectification bidirectional systems). In article, multiple candidate variables for assessed based factors such as practicality estimation accuracy. It demonstrated first time that only two variables, amplitude fundamental frequency switching waveform input current, achieve state-of-the-art obtained using simple cost-effective analogue circuitry, Gaussian process generate regression model. This estimate voltages at any angle approximate magnitude range 0–20 V normalized root-mean-square error 1% real part 1.5% imaginary part. corresponds detecting plastic container 1 kg saline (0.4% concentration, emulate electromagnetic profile muscle) distance 15 cm (1.5 radii). The results presented article were Class EF transceiver 13.56 MHz delivering up 32 W ranging from 1.1% 4%. accompanied by video file demonstrating experiments.