Performance testing and assessment of Merging Units using IEC61850

The introduction of IEC61850 offers many advantages including interoperability and flexibility, and helps to reduce downtime that occurs as a result of upgrades that may be applied within a substation, due to technology changes. One application of IEC61850 is at the process level, where a Merging Unit samples the output of current and voltage transformers (CTs/VTs), and sends the standardized digitized output to the required protection and control devices. The design and development of a Merging Unit (MU) test system will be discussed. A number of performance tests will be carried out on the MU.