Conceptual design of substation process LAN

Communication infrastructure in substations and control centres of Transmission System Operators should be designed in order to support variety of applications and users with different priorities and requirements. Communication requirements vary regarding capacity, maximum response times, availability, reliability and security. Up until a few years ago majority of process control systems communicated through serial links. Recent communication protocols (like IEC 61850) used in process control systems are based on Ethernet technology. The main goal of these protocols is to make most of Ethernet regarding accessibility and flexibility, while additionally trying to achieve high requirements on availability, robustness, response times and security in process control systems. Conceptual design described in this article encompasses optimised process control communication network in the substation, designed in order to support all existing and some of the future applications and users in substation. It defines equipment and infrastructure necessary for substation internal communication between applications and processes, as well as for substation to control/maintenance centres communication. In the suggested solution of process LAN changes that will be necessary in order to support Smart Grid were taken into account. Process control LAN will be fundamental in creating substation automation systems supporting power network of the future. The basis of process control network is Ethernet as it ensures interoperability and flexibility. Industrial Ethernet additionally provides robustness necessary for substation environment. This conceptual design of substation process LAN emphasis Ethernet over SDH and IPoSDH (attached figure). In substations modern lEDs communicate over TCP/IP, and that make them compatible with computer netwo