A Power Line Communication on DC bus with photovoltaic strings

In this paper, an innovative topology performing a Power Line Communication on DC bus, with series connected photovoltaic modules, is presented. The circuit ensures the transmission on the DC bus even if the transceivers cannot share the same reference voltage. Moreover, a circuit solution avoiding that the operating point of the photovoltaic string can be affected is proposed. The circuit is provided with an effective energy harvesting supply stage, which completely eliminates the need for external supply or batteries. Experimental results achieved by means of a commercial power line transceiver demonstrate both robustness and reliability of the proposed topology.