If an existing switchgear has to be extended, this should ideally be done without interruption to the customers supplied by the substation. This raises the question of how the new bays can be integrated and tested without having updated the existing bay controllers and, therefore, test them again.
The international standard IEC 61850 (Communication networks and systems for power utility automation) allows the implementation of interlockings and backup protection functions by means of real-time communication instead of copper wiring of signals. This results in new approaches for testing the SAS functions during operation, especially for the extension of switchgear and for bay by bay commissioning. This article describes an innovative method that uses the information of the Substation Configuration Language (SCL) as a basis.