Comparison of analogue measurements between merging units and conventional acquisition systems

This paper presents the recent progress in use the sampled measured values (SV) as described in IEC 61850-9-2 and IEC 61869. This protocol is used to replace the copper cabling for digital communication network in bringing the current and voltage measurement for protection and control substation systems. The technology is implemented through equipment called merging unit, which digitizes the analogue measurements and encapsulate the information in proper network packets. The progress in the implementation of IEC 61850 SV is corroborated by the excellent results when comparing analogue measurements between merging units and conventional acquisition systems, as presented in this work. In chapter 2, tests are carried out by comparing the standard and SV approach using a DFR. Chapter 3 and 4 include a protection relay in the tests to compare protection actuation using the two systems. Finally, chapter 5 presents results of a field application of merging units in real power system substation. In conclusion, the results and sources of error are analysed and validated.