Control of Cascaded H-bridge Converters for Power Line Communication

Power line communication (PLC) technological advancements are currently being led by the interoperation needs in applications such as smart grids, building energy management systems, electric vehicles, and the Internet of Things. In this paper, alternative control schemes are proposed and compared for the simultaneous transmission of power and digital data through the power circuits of the modules synthesizing a single-phase cascaded H-bridge multilevel inverter. The proposed PLC method does not require any additional circuit elements in the power loop for the PLC implementation. Special focus is paid to the control schemes applied to the H-bridge driving circuits to produce a low total harmonic distortion (THD) without compromising the reliability of data communication. Various parametric simulation models are designed and tested using time-division multiplexing with two variations over the assignment technique for the PLC communication task. The results suggest that the proposed low-bandwidth PLC design is robust enough to provide the required communication fidelity and capable of successfully transmitting the mixed-signal (i.e., power and data) through the power cable under various operating conditions.