Improved event based method for harmonic impedance assessment

The quantification of harmonic emission requires an accurate model of the network harmonic impedances. A number of techniques have been proposed for the assessment of the network harmonic impedances to be practical and noninvasive. This paper presents an improved noninvasive assessment technique for the evaluation of network harmonic impedances. Rapid voltage change events are evaluated to determine their validity for harmonic impedance calculations. Data filters based on the network under consideration is also introduced. Harmonic impedance values are derived for each validated event and the statistical median of the results is used to represent the network harmonic impedances. It enables an online and noninvasive tracking of network configuration and validation of simulated results.