A novel vehicle power line communication method based on switching ripple modulation

Power converters can perform power conversion and data transmission simultaneously. With the aim of mitigating the hardware requirements of vehicle power line communication (VPLC), a novel VPLC scheme based on switching ripple modulation (SRM) is proposed to eliminate the need for coupling circuits and specialized communication chips. By embedding data modulation techniques into traditional pulse width modulation systems, power/data multiplexing transmission is achieved by demodulating the voltage ripple on the DC bus. First, the theoretical foundation of the SRM is introduced, and power/data single carrier modulation using 2FSK and data demodulation based on the sliding discrete Fourier transform are provided. Subsequently, comprehensive analyses of the mutual influence between power conversion and communication in the buck converter are conducted. The impact of power conversion on communication primarily depends on the control loop compensation and perturbation depth. Moreover, the designs of the ripple conditioning circuit and communication frame are presented. Finally, an experimental prototype is constructed with two buck converters in parallel. The experimental results demonstrate a data transmission rate of 12.5 kbps within 3 m under steady-state, transient input and output voltage, and transient load conditions, validating the correctness of the proposed methodology.