Search results for " cable"

A new approach to calibrate the thermal conditions in space charge measurements on HVDC mini-cables

2019

The PEA method is currently widespread used for space charge measurements in mini-cables in order to qualify the behavior of semicon-dielectric-semicon compound under electric and thermal stress. The main goal of this research is to quantitatively evaluate the relationship between the thermal boundary conditions applied to cables or mini-cables and the maximum local electric field due to the accumulated space charge. Hitherto, several research groups have obtained thermal gradients over the dielectric's radius heating the conductor by Joule effect due to an induced current. In this paper, a numerical approach is offered to calibrate the heat exchange boundary conditions to apply to a sample…

Pulsed Electro-Acoustic space charge apparatus – qualifying, testing and monitoring of insulation for HVDC cables and accessories

2022

Partial Discharges in HVDC Cables - The Effect of the Temperature Gradient During Load Transients

2021

The paper investigates the role of the space charge accumulation phenomena in the inception of Partial Discharges (PD) in a defect within the bulk of the dielectrics of a High Voltage Direct Current (HVDC) cable. It is widespread accepted that the number of PD occurring in an HVDC cable during its lifetime is largely less than that under AC voltage stress. This is essentially due to higher values of the voltage between the conductor and the screen needed to trigger PD under a steady DC voltage than the same value under AC stress. Nevertheless, due to the dependency of the electrical conductivity of the insulation on the electric field and temperature, PD in HVDC cables is strongly influence…

“Coupling interfaces for communication transceivers over power lines”

2010

Power Line Communication in Medium Voltage Systems: Characterization of MV Cables

2008

The aim of this paper is to illustrate the development of a theoretical and experimental study on the characterization of medium voltage (MV) cables in the frequency range 25-200 kHz. Two transmission line configurations, line-ground and line-line, were considered in order to evaluate the main parameters, such as the characteristic impedance and the attenuation constant alpha. A simplified model of the line-ground configuration is proposed which allows one to evaluate the characteristic impedance and the attenuation constant by means of geometrical dimensions. The model was verified by experimental measurements on commonly used MV cables, RG7H1R, with an aluminium core of different sections…

A Model for the Study of Sheath Currents in Medium Voltage Cables for Industrial Application

2020

In this paper, the implementation of a simulation model for studying the effect of cross-bonding of metallic sheaths and/or non-magnetic armor of single-core medium voltage cables in the same circuit is discussed. With the use of single-core cables, the resistive losses due to the induced circulating currents in cable sheaths or armors causes an increase of cable temperature that reduces its ampacity. In addition, the risk of electric shock due to induced voltages may be present if a person is exposed to the armor/sheath at the unbounded end. For this reason, special bonding techniques are used to significantly reduce these currents. The authors have implemented a model that could be used t…

The Industrial Applicability of PEA Space Charge Measurements, for Performance Optimization of HVDC Power Cables

2019

Cable manufacturing industries are constantly trying to improve the electrical performance of power cables. During the years, it was found that one of the most relevant degradation factors influencing the cable lifetime is the presence of space charge in the insulation layer. To detect the accumulated charge, the pulsed electro-acoustic (PEA) method is the most used technique. Despite the wide use of the PEA cell, several issues are still present. In particular, the PEA output signal is strongly disturbed by the acoustic waves reflections within the PEA cell. This causes the distortion of the output signal and therefore the misinterpretation of the charge profiles. This, in turn, may result…

Arctic Connect Project and Cyber Security Control, ARCY

2019

The submarine communication cables form a vast network on the seabed and transmit massive amounts of data across oceans. They provide over 95% of international telecommunications — not via satellites as is commonly assumed. The global submarine network is the “backbone” of the Internet, and enables the ubiquitous use of mail, social media, phone and banking services. To these days no any other technology than submarine cables systems has not been such a strategic impact to our society without being known it as such by the people. This also means that it is at the same time a very interesting destination for hackers, cyber attackers, terrorist and state actors. They seek to gain access to in…

The ALICE experiment at the CERN LHC

2008

Journal of Instrumentation 3(08), S08002 (2008). doi:10.1088/1748-0221/3/08/S08002