Optimal filtering of synchronized current phasor measurements in a steady state

Synchronized phasor measurements have recently become one of the key topics in power system research. In order to utilize the new technology to its full potential, many issues need to be addressed. This paper focuses on the problem of synchrophasor measurement precision. A wide range of techniques aimed at the reduction of Gaussian noise present in synchrophasor data are considered. It is shown that the noise standard deviation can be accurately estimated by a variety of wavelets. Best filtering techniques are identified based on analysis of a chunk of real data sourced from phasor measurement units (PMUs) monitoring different 345 kV transmission lines. As a result, current synchrophasors measured by digital fault recorders acting as PMUs can be greatly improved by applying a proper filter.