FPGA controlled high frequency resonant converter for contactless power transfer

This paper presents a new FPGA controlled high frequency converter for contactless power transfer systems. The converter is based on full bridge discontinuous energy injection and free oscillation of a series tuned resonant circuit. The switches of the converter can be operated at a lower frequency to generate a high frequency output current. By taking the advantage of the fast response rate of a FPGA, a variable frequency controller is developed to achieve accurate ZCS operation of the switches. The experimental result has shown that the proposed converter has a very fast but smooth start-up transient performance. The output current is fully controllable with sufficiently good waveforms for contactless power transfer systems.