The Merging Unit provides a set of current and voltage samples of time synchronization for the intelligent electronic devices. The main function is to get the current and voltage instantaneous values in the power system by collecting or merging the output signals of multiple transformers, and then transport with certain data quality to the electrical measurement and relay equipment. As MU plays a key role in the data acquisition, merging and conversion before the secondary equipment of the power system, it is significantly important to perform synchronization measurements on the merging unit.
The merging units are mainly synchronized based on the full stations synchronization technology with 1PPS (second pulse) or IRIG-B as reference. It requires establishing independent optical networks with 1PPS (second pulse) or IRIG-B interfaces, which of course increases the cost and lowers the operation liability of system as well. Therefore, it becomes a trend to synchronize all stations with IEEE1588 technology.
Fig 1 Timing Error Measurement on MU
Fig 2 Time-keeping Error Measurement on MU
Fig 3 Abnormal Timing Measurement on MU