The measurement of very low conductivity and dielectric loss in XLPE cables: a possible method to detect degradation due to thermal aging

Fothergill, J.C.; Dodd, S.J.; Dissado, L.A.; Liu, T.; Nilsson, U.H.

doi:10.1109/tdei.2011.6032823

Cited by 93 publications

(36 citation statements)

References 14 publications

(24 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The effect of partial discharges on the electrical properties of the cable has been studied in a lot of investigations [16,17]. Much work has been carried out, and the chemical modifications generated by aging and its consequences on the mechanical and electrical properties of XLPE [10,[18][19][20][21] were analyzed. All these investigations are cost-effective and time-consuming.…”

Section: Introductionmentioning

confidence: 99%

Neural networks and fuzzy logic approaches to predict mechanical properties of XLPE insulation cables under thermal aging

Boukezzi

Bessissa

Boubakeur

et al. 2016

Neural Comput & Applic

View full text Add to dashboard Cite

The widespread use of cross-linked polyethylene (XLPE) as insulation in the manufacturing of medium-and high-voltage cables may be attributed to its outstanding mechanical and electrical properties. However, it is well known that degradation under service conditions is the major problem in the use of XLPE as cable insulation. Laboratory investigations of the insulations aging are time-consuming and cost-effective. To avoid such costs, we have developed two models which are based on artificial neural networks (ANNs) and fuzzy logic (FL) to predict the insulation properties under thermal aging. The proposed ANN is a supervised one based on radial basis function Gaussian and trained by random optimization method algorithm. The FL model is based on the use of fuzzy inference system. Both models are used to predict the mechanical properties of thermally aged XLPE. The obtained results are evaluated and compared to the experimental data in depth by using many statistical parameters. It is concluded that both models give practically the same prediction quality. In particular, they have ability to reproduce the nonlinear behavior of the insulation properties under thermal aging within acceptable error. Furthermore, our ANN and FL models can be used in the generalization phase where the prediction of the future state (not reached experimentally) of the insulation is made possible. Additionally, costs and time could be reduced.

show abstract

Section: Introductionmentioning

confidence: 99%

Neural networks and fuzzy logic approaches to predict mechanical properties of XLPE insulation cables under thermal aging

Boukezzi

Bessissa

Boubakeur

et al. 2016

Neural Comput & Applic

View full text Add to dashboard Cite

show abstract

“…According to Arrhenius law, the frequency corresponding to each relaxation peak obeys the Arrhenius relation with the increase of temperature, 27,28 as shown in formula (9).…”

Section: B Test Results and Analysis Of Thermal Aging In The Range Omentioning

confidence: 99%

“…Two loss peaks were observed at 1 Hz and 100 Hz on the tanδ spectrum, which was contributed by the motion of amorphous segments in the chain as well as the crystal contribution in the lamellar chain twist respectively. 9 At present, the related researches are mainly focused on the change of dielectric properties and insulation state assessment of XLPE under various aging conditions. In order to effectively control the cable leakage current, and ensure production and personal safety, it is necessary to study the influencing factors and the changing laws of the AC leakage current in the cable insulation.…”

Section: Introductionmentioning

confidence: 99%

Influence of thermal aging on AC leakage current in XLPE insulation

et al. 2018

View full text Add to dashboard Cite

Research on aging parameters of XLPE cable based on isothermal relaxation current AIP Advances 8, 075323 (2018) Cross-linked polyethylene (XLPE) has been widely used as cable insulation material because of its excellent dielectric properties, thermal stability and solvent resistance. To understand the influence of thermal aging on AC leakage current in XLPE insulation, all XLPE specimens were aged in oven in temperature range from 120 • C to 150 • C, and a series of tests were conducted on these XLPE specimens in different aging stages to measure the characteristic parameters, such as complex permittivity, leakage current and complex dielectric modulus. In the experiments, the effects of thermal aging, temperature and frequency on the AC leakage current in XLPE insulation were studied by analyzing complex dielectric constant and dielectric relaxation modulus spectrum, the change of relaxation peak and activation energy. It has been found that the active part of leakage current increases sharply with the increase of aging degree, and the test temperature and frequency have an influence on AC leakage current but the influence of test temperature is mainly reflected in the low frequency region. In addition, it has been shown by the experiments that the reactive part of leakage current exhibits a strong frequency dependent characteristic in the testing frequency range from 10 -2 Hz to 10 5 Hz, but the influence of test temperature and thermal aging on it is relatively small. © 2018 Author (s)

show abstract

“…Such changes, if present, should also affect the electrical properties of material, including its conductivity. Evidences for increase of conductivity in XLPE during thermal ageing were presented in [21] and [24], explained by weakening of molecular bonds, an increase of free volume and the resulting change of charge carriers mobility. However, the conductivity measurements performed on the used LDPE material (1 mm thick plaques) at 70 °C and 30 kV showed a decrease by about 60% from ~210 -13 S/m in the un-aged state to ~710 -14 S/m after the thermal ageing.…”

Section: Xlpe Test Objectsmentioning

confidence: 99%

Electrical treeing behavior of DC and thermally aged polyethylenes utilizing wire-plane electrode geometries

Chen

Mantsch

Huang

et al. 2014

IEEE Trans. Dielect. Electr. Insul.

View full text Add to dashboard Cite

This paper presents electrical treeing behavior in low density polyethylene (LDPE) and cross-linked polyethylene (XLPE) after exposure to thermal and DC electro-thermal ageing. Both the ageing and the treeing tests were performed by means of two different types of test objects with wire-plane electrode geometry. One type of the tested objects contained only wire electrode of 10 µm diameter, whereas in the other type the wire electrode was attached through a semiconducting tab. The ageing was performed at 80°C with and without 10 kV DC voltage of both polarities connected to the wire and lasted up to 800 hours. The AC electrical treeing tests were applied afterwards for detecting changes of material properties after the ageing. The results showed that the electrical tree inception voltage consistently decreased with increasing time of thermal exposure, whereas the applied DC electric stress had a negligible effect on the observed behavior. Similar effects were found in both the tested materials (LDPE and XLPE) though the object type also influenced the results. For the objects with semiconducting tab, a higher level of the scale parameter was registered because of shielding effect of the tab on the electric field strength at the wire electrode. It also yielded less number of trees growing in parallel at the electrode. The dominant effect of thermal stress on the ageing of LDPE was elucidated by using various analytical techniques, like differential scanning calorimetry, infrared spectroscopy, inductively coupled plasma optical emission spectrometry and oxidation induction time, and it is believed to mainly affect antioxidant content in the test objects.

show abstract

The measurement of very low conductivity and dielectric loss in XLPE cables: a possible method to detect degradation due to thermal aging

Cited by 93 publications

References 14 publications

Neural networks and fuzzy logic approaches to predict mechanical properties of XLPE insulation cables under thermal aging

Neural networks and fuzzy logic approaches to predict mechanical properties of XLPE insulation cables under thermal aging

Influence of thermal aging on AC leakage current in XLPE insulation

Electrical treeing behavior of DC and thermally aged polyethylenes utilizing wire-plane electrode geometries

Contact Info

Product

Resources

About