scholarly journals Gas measurements as a mean for identification of Partial Discharges in XLPE HV cable insulation

Author(s):  
Patrick Janus ◽  
Hans Edin ◽  
Kruphalan Tamil Selva

<p>Partial Discharges (PD) on high-voltage alternating current (HVAC) cables insulated with cross-linked polyethylene (XLPE) has a low occurrence, but consequences are usually severe since PD ultimately results in cable failures. Up until now the only efficient way to monitor HVAC cables for PD has been to install large coupling devices which are able to measure PDs directly from the power cables in order to verify if they are fault-free. These installations, usually of a temporary nature, are troublesome for several reasons like safety issues, measurement uncertainty, labor intensity etc. <br />For the purpose to ultimately create a system that is able to be utilized for PD Detection by means of gas analysis, which is easily applicable in on site, on-line conditions, initial experiments were performed in order to investigate basic material properties of XLPE and to investigate the performance of tin oxide (SnO2) sensors for such an application. For this purpose a specialized test cell was developed in order to be able to investigate different conditions which can be expected in a cable insulation system.<br />It was found from the experiments that surface discharges are detectable by means of gas analysis and that these gases penetrate an XLPE sample. It was also demonstrated that the SnO2 based sensor system displays a good selectivity to the gases emitted by PD and remain inert towards other gases emitted from XLPE samples.</p>

2021 ◽  
Vol 11 (04) ◽  
pp. 2150022
Author(s):  
Ahmed Thabet ◽  
M. Fouad

Nanoparticles succeeded to enhance the dielectric properties of industrial insulation but the presence of voids inside the power cable insulation still leads to formation high electrical stress inside power cable insulation material and collapse. In this paper, the dielectric strength of new design nanocomposites has been deduced as experimental work done to clarify the benefit of filling nanoparticles with different patterns inside dielectrics. Also, it has been studied the effect of electrical stress distribution in presence of air, water and copper impurities with different shapes (cylinder, sphere and ellipse) inside insulation of single core. In simulation model, it has been used finite element method (FEM) for estimating the electrostatic field distribution in power cable insulation. It has been applied new strategies of nanotechnology techniques for designing innovative polyvinyl chloride insulation materials by using nanocomposites and multi-nanocomposites. Finally, this research succeeded to remedy different partial discharges (PD) patterns according to using certain types and concentrations of nanoparticles.


1979 ◽  
Vol 46 (6) ◽  
pp. 1196-1199
Author(s):  
N. S. Deno ◽  
E. Kamon

A dryer is described for use in on-line breath-by-breath gas analysis systems. The dryer continuously removes water vapor by condensation and controls the sample gas at 2 degrees C dew-point temperature or 5 Torr water vapor partial pressure. It is designed to operate at gas sampling flow rates from 0.5 to 1 1.min-1. The step-response time for the described system including a Beckman LB-2 CO2 analyzer, sampling tubing, and dryer is 120 ms at 1 l.min-1. The time required for gas samples to transport through the dryer is 105 ms at a gas sampling-flow rate of 1 l.min=1.


Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3267
Author(s):  
Ramon C. F. Araújo ◽  
Rodrigo M. S. de Oliveira ◽  
Fernando S. Brasil ◽  
Fabrício J. B. Barros

In this paper, a novel image denoising algorithm and novel input features are proposed. The algorithm is applied to phase-resolved partial discharge (PRPD) diagrams with a single dominant partial discharge (PD) source, preparing them for automatic artificial-intelligence-based classification. It was designed to mitigate several sources of distortions often observed in PRPDs obtained from fully operational hydroelectric generators. The capabilities of the denoising algorithm are the automatic removal of sparse noise and the suppression of non-dominant discharges, including those due to crosstalk. The input features are functions of PD distributions along amplitude and phase, which are calculated in a novel way to mitigate random effects inherent to PD measurements. The impact of the proposed contributions was statistically evaluated and compared to classification performance obtained using formerly published approaches. Higher recognition rates and reduced variances were obtained using the proposed methods, statistically outperforming autonomous classification techniques seen in earlier works. The values of the algorithm’s internal parameters are also validated by comparing the recognition performance obtained with different parameter combinations. All typical PD sources described in hydro-generators PD standards are considered and can be automatically detected.


2000 ◽  
Vol 41 (12) ◽  
pp. 139-148 ◽  
Author(s):  
H. Vanhooren ◽  
D. Demey ◽  
I. Vannijvel ◽  
P. A. Vanrolleghem

The process characteristics of an industrial scale trickling filter plant were quantified by means of a five day intensive measurement campaign with the use of on-line respirometry and on-line off-gas analysis. Respirometry was used to measure the readily biodegradable CODst and the off-gas sensor was used to monitor the O2 and CO2 content of the off-gases. To model the biodegradation in the filters, the model developed by Rauch et al. (1999) was used. It is based on the decoupling of two basic processes in biofilm systems, substrate diffusion and biodegradation. This model was extended with equations for the production and the pH-dependent liquid-phase equilibrium for inorganic carbon (IC). The measured effluent and off-gas concentrations could be followed very closely by the calibrated model. O2 and CO2 measurements revealed that the system was not always oxygen limited. The model calibration thus required the use of a very low value of the diffusion constant for readily biodegradable substrate.


2014 ◽  
Vol 960-961 ◽  
pp. 881-884
Author(s):  
Xiao Guang Xi ◽  
Yu Yan Man ◽  
Chi Zhang ◽  
Ming Lei Wu ◽  
Yan Wei Dong ◽  
...  

In this article, a portable XLPE cable insulation detection device is introduced. Such a device utilizes electromagnetic coupling, UHF electromagnetic wave and acoustic emission to detect partial discharge signals in power cables. By analyzing the partial discharge signals and cable temperatures, the insulation status of XLPE power cables is judged.


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