Improved Time-Domain Modeling of Underground Cables

Abstract:
The accurate modeling of transients in underground cables requires the use of proper time domain models, as no reliable and efficient frequency dependent model exists. Proper frequency selection is crucial for the calculation of underground parameters in time domain modeling, especially when studying transient phenomena. In this paper, the spectrum context of various transient responses in underground cables is analyzed in order to calculate the dominant frequency. A thorough investigation on the source type, cable length, cable terminations and representation of the imperfect earth is implemented so as to determine their influence on the dominant frequency. The validity of empirical rules for the determination of the dominant frequency is also investigated. Results obtained in the time domain, using the proposed frequency, are compared with those obtained from a recently developed frequency domain model, leading to significant remarks.