Transmission of Digital Data to Cascaded H-Bridge Converters Through the Power Line

Power line communication (PLC) technologies enable the point-to-point linking between distributed power production and consumption units, thus overlaying enhanced monitoring and control capabilities to the overall power system. A novel PLC method for cascaded H-bridge converters is presented in this article, which enables the transmission of digital data by a remote terminal computer to the individual power modules synthesizing a cascaded H-bridge power converter through their power circuits. The proposed PLC method comprises an integrated framework of a digital data transmitter, receiver, and communication protocol, without using additional coupling circuits, which is suitable for cascaded H-bridge power converters with either a dc or an ac output. Its operation was tested using an experimental prototype consisting of a two-module cascaded H-bridge inverter and a field-programmable gate array device hosting the digital transmitter and receiver units. The experimental results verified the successful transmission of digital parameterization commands from a central terminal computer to the individual power modules of the cascaded H-bridge converter, along with the simultaneous transmission of ac or dc power to the load over the common power cable.