On the Analysis of Voltage and Current Transients in Three-Phase Power Systems

Artikel i vetenskaplig tidskrift, 2007

This paper presents a method for analysis measurements of voltage transients in three-phase systems. The method is based on the Clarke transform introduced in 1950 for calculations of travelling waves along three-phase transmission lines. The proposed method also shows close similarities with the classification of three-phase unbalanced voltage dips into types C and D. After extracting the actual transient, e.g. by using a notch filter centered on the power-system frequency, the three signals are decomposed into seven components. From the relation between these seven components, the dominant component is identified. The method is successfully applied to a number of measured transients. The paper also identifies the limitations of the method and gives suggestions for future work.