ABSTRACT
Electromagnetic transient phenomena in power systems are caused by switching operations, faults, and other disturbances, such as lightning strokes. ey may appear with a wide range of frequencies that vary from DC to several MHz and occur on a time scale that goes from microseconds to several cycles. Due to frequency-dependent behavior of power components and dižculties for developing models accurate enough for a wide frequency range, the frequency ranges are classišed into groups, with overlapping between them. An accurate mathematical representation of each power component can generally be developed for a specišc frequency range (CIGRE, 1990; IEC, 2006).
