10-04-2017, 09:09 PM
ABSTRACT
The implementation of the IEC61850-9-2 standard in substation automation systems requires the use of
merging units for elimination of several multiple wire connections running from the switchyard to the microprocessor
relays located in the control room. The conventional merging unit model collects current and voltage signals from
various current and voltage transformers in the switchyard, converts them into digital form and sends the digital
equivalents to the microprocessor relays via a single fiber optic cable known as the process bus. In this paper, we
proposed a new merging unit model with additional features of in-built overcurrent protection and bay control
functions. This new model is intended to provide local over-current protection and bay control for all equipments in the bay being monitored by a particular merging unit.