An IP Multicast Framework for Routable Sample Value Communication in Transmission Grids

Abstract

The growth and deployment of digital substations based on IEC 61850 in power utility industry will spawn new opportunities for wide area systems. These include monitoring, protection and control applications that will require suitable communication architectures and technologies. Techniques such as bridging and tunneling have been recommended for encapsulating and de-encapsulating messages between substations. These methods are however point-to-point solutions and are not suitable for wide area applications, involving multiple substations at the same time. In this paper, we propose using Protocol Independent Multicast- Source Specific Multicast (PIM-SSM), an IP multicast routing protocol for routable Sampled Value transmission in decentralized wide area systems. IP multicast is a technology tailored for one-to-many and many-to-many communications, such as wide area protection applications requiring multiple substations receiving R-SV messages in a single transmission from another substation in the power grid. We first show how PIM-SSM can be realized in a transmission grid communication network and present a qualitative analysis of effects on multicast when link failures occur. We then present a quantitative study to evaluate the performance of PIM-SSM, on selected communication network topologies. Our results show that the communication technology will play a critical role in efficient delivery of routable Sampled Value data in a multicast framework. Furthermore, they show that improvements in the networking infrastructure design leads to better performance of the multicast delivery.