A Full Frequency-Dependent Cable Model for the Calculation of Fast Transients

Abstract

Abstract:The calculation of frequency-dependent cable parameters is essential for simulations of transient phenomena in electrical power systems. The simulation of transients is more complicated than the calculation of currents and voltages in the nominal frequency range. The model has to represent the frequency dependency and the wave propagation behavior of cable lines. The introduced model combines an improved subconductor method for the determination of the frequency-dependent parameters and a PI section wave propagation model. The subconductor method considers the skin and proximity effect in all conductors for frequency ranges up to few megahertz. The subconductor method method yields accurate results. The wave propagation part of the cable model is based on a cascaded PI section model. A modal transformation technique has been used for the calculation in the time domain. The frequency-dependent elements of the related modal transformation matrices have been fitted with rational functions. The frequency dependence of cable parameters has been reproduced using a vector fitting algorithm and has been implemented into an resistor-inductor-capacitor network (RLC network) for each PI section. The proposed full model has been validated with measured data.

Novel Earth Fault Protection Algorithm Based on MV Cable Screen Zero Sequence Current Filter

“…Attention was paid to steady-state analysis. In order to analyze transient phenomena, one should use advanced cable line model, with cable line represented by distributed parameters [53]. The developed model is presented in Figure 3 and consist of ZNyn11 earthing transformer, power transformer, neutral point impedance, cable lines with total earth fault current equals 100 A and loads [54].…”

Analysis of Cable Screen Currents for Diagnostics Purposes

“…The earth current in single core cables is also induced when the load characteristic (dependency) of cables are different. The description of the advanced cable model for transient analysis can be found in [25]. Another model that includes ground return wire is presented in [26].…”

Refinement of the mathematical model of frequency converter cable branch with a single­phase short circuit

“…The ground fault occurrence violates the symmetry, which cannot be properly taken into account. To determine the dependence of the long lines parameters on the voltage frequency, the sub-conductor method [6] can be used, which takes into account the skin effect and the proximity effect in the core.…”