Analysis of power system transients using wavelets and Prony method

Transients resulting from switching of capacitor banks in electrical distribution systems affects power quality. The transient overvoltages can theoretically reach peak phase to earth values in the order of 2.0 p.u. High current transients can reach values to ten times the capacitor nominal current with duration of several milliseconds. Another severe operating condition is the switching on a second capacitor bank connected to the same bus. In the work, the characteristics of the transients are analyzed. The time of the beginning of a transient process is detected using a wavelet transform. The frequencies of transient components have been investigated applying the Fourier technique and the Prony model. The investigations show the advantages of the methods basing on the Prony model, over the Fourier technique. A distribution system was simulated using the EMTP software.