Analysis of the IEC 61850 protocol when used for communication during maintenance operation in an electrical substation grid

Abstract

During Substation maintenance a bay is taken out of service, tested and while testing traffic is generated on the Substation Communication Network (SCN) in a power utility. Currently in an eastern SCN at the ESKOM power utility in South Africa DNP3 protocol is utilized to communicate. This paper models the said SCN while using the International Electrotechnical Commission (IEC) 61850 protocol to communicate in order to improve performance in the network. Hence a model of a Substation Communication Network that is using the IEC 61850 protocol has been modeled in Optimized Network Engineering Tool (OPNET). IEC 61850 is a protocol that can be used in a power utility to provide interoperability between different vendors of Intelligent Electronic Devices (IED's). Most of the IED's sold by manufacturers for power utility networks support IEC 61850 protocol. The model has three scenarios and they are normal operation of a Substation, maintenance in a Substation and Buszone operation at a Substation. In these scenarios packet end to end delay of GOOSE, GSSE, SV and MMS messages are monitored. The throughput from the IED under maintenance and the throughput at the Substation RTU end is monitored in the Model. The design of the Substation Communication Network using IEC 61850 will assist when trying to predict the behavior of the network with regards to this specific protocol during maintenance and when there are faults in the communication network or IED's.