Simplified protection system architecture based on IEC61850 for the next generation IED´s

Due to the advancement of technologies, Intelligent Electronic Devices, (IED´s) can handle multiple protection and control function. IED61850 standard allows high levels of data that can be exchanged between IED´s from different product suppliers. These developments will enable innovative re-design of the secondary substation protection systems compared with current industry practices, where different IED´s for individual bay functions such as Line Differential, Distance, Bay Control Units and Busbar protection are utilised. This paper challenges the current technical specifications developed within utilities by reducing the number of protection IED´s required to perform protection and control functions prescribed by the current industry practices. In this case, the overall protection system architecture will be more readily available and major cost savings could be achieved. This can be realised by selectively activating required protection functions within each Bay IED. The Busbar protection function is performed by the Bus bar Central Unit IED based on the Primary System data transferred from each Bay IED. In order to comply with the current protection redundancy requirements demanded by utilities, this system architecture has to be duplicated, preferably with a functionally identical system, provided by another supplier. The paper details the challenges inherent within this new protection architecture and attempts to answer the following questions: 1) Do utilities need to change their practices now? 2) Do these architectures truly optimise cost/performance versus professional engineering services, maintenance routines, retrofits, spares holdings? 3) Are suppliers ready to meet these technical challenges?.