Active Rectified LLC Resonant Converter Using Combined Frequency and Phase Modulation for Talkative Power Conversion

Talkative power conversion (TPC) is a promising communication solution for the DC distributed power system (DPS). It involves embedding data into the output power ripple of a converter by using the power and signal dual modulation (PSDM) method. This paper proposes a frequency shift keying (FSK)-based method for active rectified LLC resonant converters (ARLLC). The method integrates the communication function into the power conversion by modulating data into the switching carrier. The phase control of the secondary active rectified switching devices is employed to suppress the input-output voltage gain fluctuations caused by frequency modulation, thereby avoiding communication's influence on power conversion. For data transmission, no additional hardware or cabling is required, reducing the complexity and costs. In addition, a detailed design guideline considering both communication and power conversion is provided, facilitating the general TPC-ARLLC system design. Finally, a 500 W prototype with a resonant frequency of 120 kHz is constructed, and the experiment achieves a 10-kbps bitrate with a 0.33% maximum output voltage fluctuation ratio, demonstrating the correctness of the proposed modulation method.