Calibration of Phasor Measurement Unit at NIST

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Calibration of Phasor Measurement Unit at NIST (667.36 KB)

Phasor Measurement Units (PMUs) are being deployed on electric power grids to monitor their static and dynamic behavior. The information they gather is important to detect problems on these systems and to prevent blackouts. The PMUs require time synchronization of the data taken across the grids. This is done using Coordinated Universal Time (UTC) usually derived from the Global Positioning System (GPS). This paper describes the basic operating principles of PMUs and their time requirements to estimate absolute phase angles. A National Institute of Standards and Technology (NIST) PMU calibration system that tests PMU performance necessary to meet the IEEE synchrophasor standard requirements is discussed. The calibration of voltage, current and time measurements for the NIST PMU test system is described. The total vector error (TVE) of the NIST PMU test system is estimated to be 0.05 %. A comparison between the NIST PMU test system and a prototype commercial PMU calibrator was performed to assure traceability of relevant electrical measurements and time measurement.