Calibration of Phasor Measurement Unit at NIST

This paper describes the basic operating principles of Phasor Measurement Units (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 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.