Researchers from University of Cagliari developed a power line communication system to perform the digital transmission in a distributed energy storage system including electric vehicles
Smart grid is the digital technology that allows for two-way communication between the utility and its customers. A smart grid facilitates information flow among various components of the grid. In smart grids, electric vehicles (EVs) have an influence on energy storage through vehicle-to-grid (V2G) technologies. Power line communications (PLC) provides broadband data communications on conductors already used for electric power transmission using a modular signal. Now, a team of researchers from University of Cagliari used broadband (BB) PLC technology to manage a distributed energy storage system integrated with a smart grid.
Use of PLC in V2G application eliminates the need for installing additional communication grid. Moreover, the use of dedicated modulation techniques such as orthogonal frequency division multiplexing (OFDM) facilitates a broadband transmission. The team focused on optimally designing PLC system as a multi-objective optimization problem with the following three conflicting objectives: maximizing Bit rate (𝐵𝑅) and minimizing the bit error rate (𝐵𝐸𝑅) and the interference on adjacent equipment. The optimization problem includes assignment of the sub-carriers to the single charging stations as many charging stations share part of the transmission line.
The team also developed an algorithm, called Chimera to enhance the allocation of sub-carriers to the nodes served by the same feeder. The OFDM symbols are sent by all the transmitters and are merged into one and travel in all the channels. Chimera allows to perform the multi-channel optimization of the OFDM modulation scheme. The team found that the design procedure enables to solve the bit-loading problem and finds a compromise among the conflicting objectives of minimal signal power and 𝐵𝐸𝑅, while maximizing the 𝐵𝑅. The optimization process also offered Pareto-optimal solutions, which are states of allocation of resources—the designer can perform the definitive choice depending on the hardware and the communication requirements. The entire constellation system can be designed after making an appropriate choice. The research was published in the journal MDPI Energies on May 09, 2019.