Optimization of Power Line Communication System Using a Resonant HVDC Bus in a Distributed Renewable Energy Generator

Abstract

The development of smart grid architecture for renewable energy production system is intensively studied for the possibilities that this architecture offers to optimize the global production and to increase the efficiency of the generator by monitoring individually the various sources subjected to diverse working conditions. To assume monitoring and intelligence in the grid and to communicate between remote stations and a central master one, a communication system needs to be associated to the power grid of the global production equipment. In this contribution we analyzepower line communication solutions in terms of quality of transmitted signal, efficiency and electromagnetic compatibility. We analyze the working modesof communication interfaces based on power line communication using the amplitude-shift-keying (ASK) modulation and integrating a light protocol of Modbus type. We point out that basic solutions offer poor quality of signal and generate a lot of harmonics of the fundamental carrier inducing important electromagnetic perturbations. An original solutionis thus developed, based on a narrow spectrum carrier on resonant HVDC bus working at a low frequency allowing to minimize the generation of harmonics and thus to increase the quality of the transmitted information. A PLC interfaceis then implemented in a hardware circuit and test pointing out the advantages of the PLC communication based on a resonant HVDC bus with sinusoidal carrier for renewable energy generator.