Estimation of transmission line parameters single-core XLPE cables considering semiconducting layer

Int. Trans. Electr. Energ. Syst.

et al. 2016

Self Cite

High frequency signal components from partial discharge in an underground power cable propagate according to available modes provided by the cable structure. Which mode or combination of modes is detected depends on type and installation of sensors. Without the ground return impedance, the earth screen voltage is assumed to be equal to the ground potential and all current will flow through phase conductor(s) and earth screen. However the soil may contribute to the transmission line propagation modes and affect the detected partial discharge signals. This paper investigates the effect of the ground return path on partial discharge detection at cable ends. Existing theory and modeling (modal analysis, ground impedance) are customized for the analysis. Transmission line parameters measurements approve the modelings. Time domain signal propagation simulation shows that the ground mode has a minor contribution to the signal propagation. The implication for partial discharge detection is discussed.

Section: Discussion and Simulation Resultsmentioning

confidence: 99%

Section: Partial Discharge In Single-core Cablementioning

confidence: 99%

“…Detailed description of each parameter in Z and Y can be found in [2,13,14]. Figure 2 shows the impedance and admittance matric components in (1) based on the parameter values in Table I.…”

Section: Model Basicsmentioning

confidence: 99%

Section: Modal Voltages and Currentsmentioning

confidence: 99%

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Effect of ground return path on partial discharge signal propagation along single-core and three-core power cables

Int. Trans. Electr. Energ. Syst.

et al. 2016

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“…( 15) where z 1 is the core impedance incorporating conductor screen; refer to reference [8,9] for detailed formulas. Compared with (6) and (7), the parameters in (15) have the same meaning as for PILC.…”

mentioning

confidence: 99%

Estimating Transmission Line Parameters of Three-core Power Cables with Common Earth Screen

Wagenaars

et al. 2018

NORD-IS

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<p>The propagation modes of travelling wave in a threecore power cable (XLPE or PILC) with common earth screen can be uncoupled into three modes: one shield to phase (SP) mode and two phase to phase (PP) modes. A generic model approach is applied in this paper to estimate the transmission line parameters of three-core cables with common earth screen, which includes the effect of different layers on series impedance and admittance. The characteristic impedance, the propagation velocity and the attenuation for SP and PP modes of two cable types, PILC and XLPE are modeled and compared with test results. Calculated parameters match within 5% for the characteristic impedances of different modes and 5% for the velocity for the PILC cable. Larger deviations occurred for XLPE cable, due to difficulties in appropriate modeling the semiconducting insulation screens around each conductor. The attenuation for both PILC and XLPE is hard to predict because data on complex permittivity, being the dominant factor, is hardly known.</p>

Core asymmetry influence on transmission line parameters of three‐core power cables

IET Science Measure & Tech

Wagenaars

et al. 2021

Self Cite

Time-domain reflectometry applied for power cable diagnostics employs transmission line parameters to determine signal shape and delay. This paper proposes to utilize pulse reflection measurement to evaluate the symmetry of a three-core power cable as part of production quality assessment. For a rotation-symmetric three-core power cable, transmission line parameters can be obtained analytically, and with modal analysis propagation channels can be decoupled. Asymmetry caused by inaccurate core positioning complicates the decoupling process. This paper utilizes the "field-circuit" approach for the analysis. The finite element method is used to obtain the electromagnetic field distribution for two types of asymmetry introduced in a cable design. Modal analysis results are validated by considering asymmetry as a perturbation of the symmetric cable design. The influence of asymmetry on the time-domain pulse response is simulated. Deviation from a symmetric configuration is observable, in particular in terms of propagation velocity, which can be employed to assess cable manufacturing accuracy.