School of Electrical & Electronic Engineering, North China Electric Power University, Baoding 071003, China

The hardware design of traditional power line communication scheme is complex. The DC-DC converter has the potential to send data, and can carry out power/data multiplexing transmission. In this paper, a modulation scheme for power electronic switch based on quadrature frequency shift keying is proposed. By modulating the switch frequency, the data information is embedded into the original pulse width modulation (PWM) signal, so that the voltage ripple carries the frequency characteristics of the data. Then the data receiving is realized by the demodulation scheme based on sliding discrete Fourier transform, and ultimately the synchronous transmission of power/data is realized. Firstly, the relationship between PWM signal and voltage ripple frequency is proven; Then, the schemes of data modulation and demodulation are presented; Taking the load changing condition as an example, the buck converter is modeled to analyze the interference of power conversion transient process on communication; Finally, an experimental platform composed of two buck converters is built to achieve a communication rate of 20 kbit/s. The effectiveness of the proposed scheme is verified with the photovoltaic optimizer as the application background.

This work is supported by National Natural Science Foundation of China (No. 52177083).