High Resolution Harmonic Power Flow and Passive Harmonic Impedance Measurements

The measurement of power quality, especially the spectral composition of voltage and current signals is becoming more important as the power grid becomes more diversified and inverter-fed generation is taking over. Measuring the complex harmonic spectra of those quantities enables the calculation of harmonic power flows as well as an estimation of the harmonic grid impedance without an external signal injection in case of negative power flows. In this paper, the general idea is presented based on a simple model at first. Thereafter, measurements obtained by a novel Power Quality Measurement System are presented to show the viability of those kinds of measurements.