A Novel Three-Phase Omnidirectional Wireless Power Transfer System With Zero-Switching-Loss Inverter and Cylindrical Transmitter Coil

Aiming at the problems of large switching loss and large output power fluctuation in the existing omnidirectional wireless power transfer (OWPT) system, a novel OWPT system with zero-switching-loss inverter and cylindrical transmitter coil is proposed. By introducing an auxiliary resonant network with simple structure and low-loss on each phase arm of the three-phase inverter, zero-voltage switching turn-ON and zero-current switching turn-OFF within the full power range can be acquired. The switching loss in the main circuit of inverter is reliably eliminated. The transmitter coil is a cylindrical coil composed of the three curved rectangular coils, whose excitation current amplitude is equal and the phase difference is 120 degrees. It can arise a spatial rotating magnetic field around the transmitter coil and provide an omnidirectional energy transmission channel. The operating principle of soft-switching is analyzed in detail, and the design rules of soft-switching in full power range and the parameter design method of coupler to reduce the fluctuation of output power are given. Ultimately, an experimental prototype is used to verify the feasibility of the proposed OWPT system. The experimental results indicate that the system output power is retained at 93.4-104.7 W and transfer efficiency is retained at 71.2%-78.1% under arbitrary angular misalignment of receiver.

Automated summary

A novel omnidirectional wireless power transfer (OWPT) system is proposed to address the issues of large switching loss and output power fluctuation in existing systems. The system utilizes a zero-switching-loss inverter and a cylindrical transmitter coil. By introducing an auxiliary resonant network and employing soft-switching techniques, the switching loss in the inverter's main circuit is eliminated and stable power transmission is achieved. Experimental results confirm the feasibility of the OWPT system, demonstrating retained output power and transfer efficiency under various receiver misalignment angles.