Voltage and frequency time series analysis improvements in transforming data from quality survey into information

The paper investigates the nature of voltage and frequency time series. The analysis is based on long term half cycle survey fulfilled with dedicated IEC 61000-4-30 class A equipment. The aim of our investigation is to improve the usefulness of half cycle data gathered in measurement campaigns. In order to do this, IEC 61000-4-30 requirements are analyzed with respect to the concept of data, information, knowledge pyramid. We present one simple way to improve the usefulness of data by drawing boxplot charts instead of using aggregated values as described in the standard. Second investigation is basic patterns identification used in order to better describe frequency. In the end, the hypotheses of fractal behaviour of voltage/frequency time series is tested by calculating Hurst exponent for different periods of time.