Statistical Behavior of PMU Measurement Errors: An Experimental Characterization

Abstract

Different power system applications based on synchrophasors measured in different nodes of the electric grid require information about the statistical distribution of the errors introduced by the Phasor Measurement Units (PMUs). The performance of these applications can be significantly affected by possible incorrect assumptions. The Gaussian distribution has been historically assumed in most of the approaches, but some more recent studies suggest the possibility of considering different distributions for a more accurate modeling of the actual situation. In this paper, proper statistical tools applied to the results achieved through a high performance experimental test system are proposed to assess the statistical distribution of PMU errors under controlled steady-state conditions, thus providing a basis for defining suitable models to be used in the specific applications.

Compensation of Systematic Errors for Improved PMU-based Fault Detection and Location in Three-Phase Distribution Grids

“…• PMUs provide 50 measurements per second. In steadystate conditions (pre-fault) PMUs are assumed to have maximum magnitude error of 0.1 % and maximum phaseangle error of 0.1 crad (see [43]), whereas, by default, they have a maximum TVE of 3 % in post-fault conditions (see [42]), indicated as TVE3 in Table I. Depending on the dynamics detected for the node voltages, other maximum voltage errors can be assumed, as summarized in Table I and described in what follows.…”

“…ξ i,p and α i,p are the magnitude and phase-angle errors of v i,p and superscripts sys and rnd indicate their two errors components: systematic, mainly attributed to Voltage Transformers (VTs), and random, mainly associated with PMUs. Such classification is typically valid when accurate commercial PMUs are considered (see, e.g., [43]), but the method is robust in the presence of systematic PMU errors. It is then possible to assume that ξ sys i,p and α sys i,p can remain essentially unchanged after fault compared to steady-state conditions.…”