International standards for PMU and tests for compliance: the synchrophasor standard

Phasor measurement unit (PMU) devices, and the standards to govern PMUs, have progressed since the first standard appeared in 1995. The early standards contained significant ambiguities in the definition of the phasor time - tagging, and no independent verification facilities existed to test compliance with the standards. The latest standards, as a result of significant effort on the part of the IEEE working group, contain extremely detailed test descriptions and requirements. The standards are also supported by a number of facilities/companies which are capable of independently verifying compliance, using traceable amplitude and time/phase measurement chains. This provides a high level of confidence in a basic interoperability of PMU devices during "normal" operation. However, as the power network evolves in the future, with dynamic events becoming more commonplace, and imperfect power quality becoming perhaps the "norm", care still needs to be exercised since the actual PMU outputs during dynamic and imperfect network conditions are still specific to the actual device hardware, algorithm/filter, and configuration/settings.