Toward distributed intelligent: A case study of peer to peer communication in smart grid

Smart grid is an emerging cyber-physical system which aims at making power systems more intelligent and efficient. One of the major attributes of smart grid is integration of distributed renewable power resources into the traditional power grid. As a result, traditional centralized control is not always effective in smart grid, and distributed control is essential for flexible energy management. To facilitate distributed control, Intelligent Electronic Devices (IEDs), which are embedded computers equipped on power devices, are interconnected based on the peer-to-peer communication model. An open question is whether such a distributed control mechanism over peer to peer communication is delay-efficient to support time-critical smart grid applications. To answer this question, we establish a micro smart grid, called Green Hub, to measure the delay performance for both distributed and centralized control systems. Our results show that, for computationally intensive applications, the delay performance of the distributed system is worse than that of the centralized control system, mostly due to IEDs' limited capability. In addition, we find that in distributed control systems, the peer to peer communication may cause different behaviors of physical devices in power systems, and consequently deviates their decisions from optimal. Our experimental study reveals the distributed control system in smart grid does not necessarily performs better than the centralized control system for certain applications, and the peer to peer communication in the distributed control system may bring new concerns which did not exist in the centralized control system. A special attention need to be paid on the effectiveness and efficiency aspects when design algorithms/schemes for smart grid.