Experimental characterization of time synchronization over a heterogeneous network for Smart Grids

Nowadays, the growing presence of distributed energy resources (DER) makes the management of the distribution grid more complex, thus requiring distributed monitoring and controlling capabilities. The deployment of locally distributed intelligent devices over a large area involves a high performance network infrastructure (typically based on heterogeneous communication technologies) in order to provide the most appropriate level of communication. In addition, monitoring and control applications need a common sense of time to coordinate the activities among distributed devices, but accurate time synchronization in a heterogeneous network is still a challenge. Network Time Protocol (NTP) can distribute time information with accuracy in the order of milliseconds on a Wide Area Network (WAN). In this work, an experimental characterization of NTP synchronization performance on a real network for Smart Grids has been done. The first analysis highlights the synchronization capabilities span from 1 ms to 20 ms depending on the technology adopted for the deployment of the network (e.g. fiber optics links, BPL links and Wi-Fi).