Analysing the real-time-capability of wide area communication in smart grids

Current developments towards Cyber-Physical Energy Systems (CPES) [1] requires the close integration of traditional power grids and appropriate Information and Communication Technology (ICT) infrastructures. Driven by additional requirements of future monitoring and control, increasing amounts of data have to be handled to ensure safe operation of the power grid and to maintain frequency stability. Therefore an appropriate ICT infrastructure becomes crucial for enabling fast and reliable transmission of time critical messages such as switching commands. This paper provides an evaluation on the real-time capability of the communication network in three scenarios analysing different levels of the power grid infrastructure: within the substation, between neighbouring substations and between a substation and the control centre. Communication is modelled according to the standard IEC 61850 using both simulation and the analytical approach of Network Calculus. Thus, we determine mean values as well as worst-case bounds on the delay of messages, evaluating the impact of varying network and traffic conditions. The results highlight the applicability of IEC 61850-based communication as a holistic solution for the power grid, supporting advanced tele protection and remote control applications.