Modeling of substation architecture implementing IEC 61850 protocol and solving interlocking problems

Abstract This paper presents a study concerning the implementation of the 61850 standards (TCP/IP based standards for electric substations). The integration of communication networks in critical or safety applications is nowadays a strategic research problematic. The study presented here aims at implementing the 61850 protocol onto electrical substation architectures. This protocol is based upon the TCP/IP protocol with IEEE 802.1p/q priority mechanisms. The first studied architecture is a classical architecture composed of a TCP/IP network for the higher layers (supervision level) and a ModBus-Serie network for the lower layers (sensor level), both interconnected through a concentrator. The second architecture uses only one network (TCP/IP) interconnecting all the devices. So the implementation of the 61850 protocol on these architectures requires to study the compatibility of the standards. For that, we analyze the various information flows which are sharing the networks, and check that the constraints (time for alarm messages to reach the receiver) are respected. A study using OpNet and some results and comments are presented in this paper. In future works, the two architectures will be compared in terms of performances, costs and security.