Analysis of IEEE 1588-based Cyber Physical System for micro grid automation

The micro grid is a cluster of electricity generators, energy storage systems, and loads that can operate connected, as well as disconnected, from the distribution grid. In this paper the time related characteristics of Cyber Physical Systems (CPCs) to be used for (IEC 61850-based) automation of micro grids are investigated. Specific constrains are taken into account as, for instance: the use of heterogeneous communication networks; the reuse of any existing wired and wireless network and assets; and the deployment of new renewable power sources or energy storage systems into traditional (old) grids. The proposed approach relies on IEEE 1588 infrastructure placed in the key positions of the Micro grid to build a backbone for precise distribution of time reference to IEC 61850 device, (which are used to guarantee the interoperability with the distribution grid). The proposed solution is installed inside the campus of the University of Brescia in a real micro grid. The experimental results show the feasibility of the proposed approach, with overall latency and jitter in good agreement with the usual requirements of IEC61850: for instance, the total estimated end to end delay (latency) including the backbone (i.e. 3 cascaded Ethernet switches) is below 0.6 ms.