Analysis of the implementation approaches to the wireless energy transfer systems using low-frequency magnetic field

The aim of the work is to analyze the processes in the wireless energy transfer system using low-frequency magnetic fields, implemented with the use of a resonant air transformer and finding approaches to improving the efficiency of such systems. The steady state of the wireless transmission system with a resonant tuned transmitter coil has been evaluated using first harmonic analysis (FHA) method. It has been shown that the necessary condition for maximum power in the receiver is not only tuning the receiving coil into resonance, but also loading the receiving tank with a strictly defined active load resistance, that depends on the transmitting -to- receiving coils coupling coefficient. The estimation of the maximum transmitted power has been done, the requirements to the rectifier of the receiver that will make it possible to work with the maximum power in the load have been determined. It is proposed to use an active rectifier in the receiver with an appropriate specialized control system, which works with the maximum power point tracking (MPPT) algo-rithm and allows fine tuning of the receiving tank in real-time by controlling the phase shift between voltage and current. The proposed approach in wireless charging systems will increase the efficiency of their operation and reduce the battery charging time