On April 28, the automation and protection world took a giant step forward when Tennessee Valley Authority (TVA) inaugurated its Bradley Substation. The event heralds the first IEC 61850-compliant substation where all of the available features promised by the communications standard were implemented and proved to work in a 500 kV transmission substation.

Siemens provided SIPROTEC protective relays and SICAM PAS substation automation hardware and software. The Siemens configuration software, DIGSI, set the early standards and was the first commercially available IEC 61850 configuration tool.

The security features of the SIPROTEC relays include the ability to ensure that only authorized IEC 61850 clients can access the relays on this secure network.

TVA accomplished the goals that were set out for Bradley: Use the IEC 61850 standards to reduce the number of wires, components and connections in a substation protection control house design; use the interoperability features between vendors to further reduce wiring connections and retain the benefit of having redundancy without a single mode failure problem; and reduce the costly cabling and wiring between the switchyard breakers and the control house..

During the final commissioning, the Siemens SIPROTEC relays identified and alerted the project team to numerous issues in the now critical communication infrastructure, which consists of various third party equipment for communication and multiple vendors' relays in addition to Siemens components.

The watchdog program in the SIPROTEC relays detected missing information caused by issues in the fiber installations and detected problems in the settings of communication switches that did not filter circulating telegrams from the system. It provides essential information of the health of the wiring connections now done through generic object oriented substation event (GOOSE) messaging on the communication network.

According to TVA Manager of Protection and Control Jim Kurtz, TVA's Bradley Substation set many "firsts" including the first 500 kV transmission implementation, first time a utility acted as the integrator, first time GOOSE messages were used for secure high speed tripping, and the first time GOOSE messages between different vendors' relays were used to realize protection logic and control.

The implementation of IEC 61850 is a reality now. Short lead-time, cost-effective, repeatable and flexible protection and control systems can now be designed and implemented at the highest voltage levels.