Enhanced Power Line Communication Strategy for DC Microgrids Using Switching Frequency Modulation of Power Converters

To improve the reliability of dc microgrids operation, an enhanced power line communication (PLC) strategy is proposed using switching frequency modulation (SFM) of a power converter. The proposed PLC strategy uses the voltage ripple on the dc bus voltage, which is inherently generated by converter's switching activities as an information signal. By using the SFM, all microgrid components sharing the dc bus as communication channel can obtain power flow information with fast Fourier transform analysis of dc bus line frequency. In addition, the operating performance of the dc bus voltage regulator is enhanced over a range of light load conditions. The proposed PLC strategy and design of modulated frequency range are verified through experimental results using a 3.3 kW prototype dual active bridge converter.