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

Abstract

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.

Edge Computing Based Fault Sensing of the Distribution Cables Based on Time-Domain Analysis of Grounding Line Current Signals

“…It can be seen that the three-phase conductors together with their sheaths are all arranged in an equilateral triangle. Since the structures are symmetrical, the three-core cables have the symmetric electrical parameters described by [34]…”

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

“…Based on the cable geometry and material properties, the impedance and admittance matrices can be estimated analytically [26,27]. Measured results for the attenuation, propagation velocity and characteristic impedance are compared with the calculated ones by analytical estimation and FEM, as shown in Figure 5.…”

High‐voltage cable bonding to prevent cable termination faults based on zero‐sequence current

“…Thus, the sheath voltage, the imbalanced electric field, and cable temperature on cable terminations increase due to zero-sequence currents. 23,24 The sheath voltage can extremely increase in single-point bonding, solid bonding, and cross bonding methods due to zero-sequence currents, so surge arresters should be used to prevent high voltage on metallic sheath of cable. However, surge arresters can easily fail, and high voltage occurs on cable terminations and cable joint points.…”