Assessment of Timing Requirements of Phasor Measurement Units

Abstract

Accurate time synchronization of Phasor Measurement Unit (PMUs) play an important role in application of synchrophasor technology. Dierent time distribution methods are present which are capable of synchronizing Intelligent Electronic Devices (IEDs) with dierent timing accuracies. Initial part of this report presents information about some of the high-accuracy time distribution methods which were studied and evaluated based on their usability for synchrophasor applications. Later part of the report assesses timing requirements for PMUs by carrying out tests in a controlled experimental environment. In the past, generally PMUs were tested using a stand-alone relay test kit. A major drawback of this type of testing set-up is that it does not tests the PMUs in their practical operational environment which includes an instrumentation channel feeding input signals to the PMU. Overcoming this drawback, a new generic real-time Hardware-in-the-Loop (HIL) test set-up has been used to assess timing requirements of commercial PMUs in the laboratory. The results obtained showcase the eect of instrumentation channel on phase errors and also in determining timing requirements of PMUs. Insightful information showcasing the behaviour of PMU estimates in case of jitters in timing signals has also been presented.