Communication protocols and networks for power systems-current status and future trends

Minimizing implementation time and manual configuration, as well as straightforward upgradability are the key requirements of efficient substation automation systems. For larger utilities this often necessitates achieving interoperability between different devices from multiple vendors. Since the early 1990's it was noticed that the speed of advances in communication technology seemed to overpass its power system counterpart, which called for more adaptability by substation automation systems and higher independence from the underlying communication technology. The natural shift in the industry from proprietary communication protocols to open access standards was therefore further accelerated and was directed towards more advanced solutions that provide an interoperable and future proof environment. In order to be able to respond to these concerns, IEC 61850 was proposed as a future proof, adaptable communication protocol, capable of providing interoperability in a multi-vendor environment and with a highly advanced object oriented modeling structure. The migration from legacy protocols and de facto standards such as Modbus, DNP3, and IEC 60870-5 has already started and it seems likely that it will continue at a steady pace in the future. In addition to the efforts to provide an advanced solution for substation automation systems, there is also a need for extending the ldquoautomationrdquo benefits to beyond the substations either downstream, at the feeder level or upstream, at a higher level of network management. The objective of this paper is to provide an overview of the current status of communication networks for substations using IEC 61850, and also discuss the possible future trends for extending the scope of the standard and using its capabilities for other applications within the distribution system.