Power Line Communication Management of Battery Energy Storage in a Small-Scale Autonomous Photovoltaic System

Today an increasing number of batteries are equipped with a digital battery management system (BMS) either for safety issues or lifetime improvement, or for both. In order to avoid the use of dedicated wiring for communicating with these BMS, a power line communication (PLC) solution is proposed to communicate through the dc power line inherent in these systems. This solution is also designed to be directly compatible with the existing controller area network controllers integrated in a large number of commercially available microcontrollers. It uses a single carrier generator in order to generate a shared carrier signal on the bus. Each modem can modulate this common carrier signal by switching the impedance it presents on the bus. In a first part, this paper proposes an overview of the industrial context of this PLC solution, including simulation results and discussion of the theoretical limits of the system. Then, the digitization stage interfacing the controller to the power line is described and a first prototype is validated through discussion of experimental results obtained within an actual industrial environment.