Frequency Domain Aspects of Electromagnetic Transient Analysis of Power Systems

On the accuracy of the Phase-domain model for EMT analysis of transmission lines and cables

“…where Y c = YZZ -1 (4) and H = e -L YZ (5) Y and Z are the respective matrices of series impedances and of shunt admittances in per unit length Fig.1b shows an equivalent circuit of the line at Fig. 1a that is in the frequency domain and that follows from expressions (1)-(3).…”

“…1a and 1b has the following two-port nodal representation: Here ω is the angular frequency and c is a suitable damping factor. Let F(s) denote one of the variables of interest and f(t) its time domain image [4]; thus:…”

“…Note that (25) implies that the frequency range of the analysis has been truncated to a maximum frequency F max =1/2Δt. This truncation produces Gibbs' errors in the time domain and the purpose of the data window σ k in (25) is to minimize these errors [4,7]. The Von Hann or Hanning window is the one applied here [4].…”

“…This truncation produces Gibbs' errors in the time domain and the purpose of the data window σ k in (25) is to minimize these errors [4,7]. The Von Hann or Hanning window is the one applied here [4]. Evaluation of (25) is performed with the Fast Fourier Transform (IFFT) algorithm.…”

“…Another line model that also accounts for all frequencydependent features of line propagation is the one based on the two-port nodal form of line relations and on the Numerical Laplace transform (NLT) [4,7]. This model cannot perform sequential simulations of transients; nevertheless, it offers a high and well-determined numeric accuracy.…”