IEC 61850 Process Bus - It is Real!

Authors: Damien Tholomier and Denis Chatrefou, AREVA T&D

IEC 61850 Process Bus - It is Real!

The new international standard for substation communications IEC 61850 allows the development of a new generation of substation protection,
automation and control systems that results in significant reduction of the overall cost of such systems, while at the same time improves the functionality of different applications. Non-conventional instrument transformers with digital interface based on IEC 61850-9-2 process bus eliminate some of the issues related to differences in protection and metering requirements. The data can be processed by any device to perform different protection, automation and control functions.

The IEC61850 international standard for communications in substations brings a new era in the development of substations. It affects not only the design of the substation protection, monitoring and control system, but also the design of the substation secondary circuits. High-speed peer-to-peer communications using GOOSE messages and Sampled Analog Values allow development of distributed applications based on current and voltage values communicated between devices connected to the process and substation local area networks.

Over the past few years, the market surge towards to IEC 61850 has been evident for suppliers and customers alike. Much of this interest has centered on the migration from manufacturer-driven station bus implementations, towards substation automation systems that fully integrate IEDs such as protection relays on the new accepted international standard.

This approach has largely concentrated on the IEC 61850-8.1 station bus, emulating and improving on the conventional SCADA approaches and the replacement of hard-wired signal exchange between substation protection and control devices with GOOSE messages. However, the station bus is only a part of the advancement that IEC 61850 can offer, with IEC 61850-9.2 being largely unexplored. IEC 61850-9.2 is the part of the standard that brings non-conventional instrument transformer technology (NCIT) into play, breaking the shackles and constraints of conventional CTs and VTs with iron wound cores at their heart. NCIT has some relative advantages such as elimination of transients, improvements in safety and accuracy, reduction in wiring costs, and the resulting effect on substation topology. More than 15 years of advanced research and different projects around the world are proving the great potential of this technology.

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Relion advanced protection & control.
BeijingSifang June 2016