A Novel High-Voltage Power Supply With MHz WPT Techniques: Achieving High-Efficiency, High-Isolation, and High-Power-Density

Abstract

This article presents a wireless high-voltage power supply (WHPS) that leverages MHz wireless power transfer (WPT) technology with the double-sided <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">LCC</i> compensation topology, achieving high-voltage, high-isolation, high-efficiency, and high-power-density performance. The design utilizes magnetic resonant WPT for primary and secondary side isolation and incorporates multiple receiving coils on the secondary side. Rectifying each coil separately generates multiple direct current (dc) voltages, which are connected in series to produce high voltage output. To attain high power density, stacking of receiving coils and integration of compensation inductors are implemented. However, due to the close proximity of these components, strong coupling results in both mutual inductance and parasitic capacitance. A compensation parameter design method is proposed to decouple mutual inductance and ensure resonant and voltage equalization across each stage. The spatial structures of the coils and inductors are also specifically designed to mitigate the impact of parasitic capacitance, enabling the system's resonant frequency to be elevated to MHz levels. Finally, an 800 W/1.875 MHz WHPS prototype was design and fabricated. Experimental results show that the prototype is capable of converting a 150 V input into a 10 kV output, while maintaining a dc–dc efficiency exceeding 90% across a wide range of load conditions, from 6% to 100%. Moreover, the developed prototype demonstrates a power density of 3.66 kW/L (60 W/in <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> ) and an electrical insulation performance surpassing 35 kV ac.