Temperature correction to dielectric modulus and activation energy prediction of oil-immersed cellulose insulation

Liu, Jiefeng; Fan, Xianhao; Zhang, Yiyi; Zheng, Hanbo

doi:10.1109/tdei.2019.008530

Cited by 59 publications

(38 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Finally, relaxation optimization was carried out on the optimized model under the canonical ensemble (NVT). After the geometry and relaxation optimization of the system, an initial amorphous cell respectively containing 20 and 40 cellobioses was established, the energy was minimized and the density of model was adjusted to 1.59 g/cm 3 [28]. After the above treatment, the established molecular model was consistent with the actual situation, as shown in Figure 4b.…”

Section: Simulation Detailsmentioning

confidence: 84%

“…Mineral-oil-immersed transformers are widely used in high-voltage transmission systems due to their high insulation strength and long service life. The safe and reliable operation of power systems depends on the condition monitoring and timely maintenance of power transmission and transformation equipment [3]. As the key equipment of power transmission and distribution, the failure of the transformer may lead to serious power system accidents [4,5].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

A Molecular Dynamics Study of the Generation of Ethanol for Insulating Paper Pyrolysis

Zhang

et al. 2020

Energies

Self Cite

View full text Add to dashboard Cite

Cellulosic insulation paper is usually used in oil-immersed transformer insulation systems. In this study, the molecular dynamics method based on reaction force field (ReaxFF) was used to simulate the pyrolysis process of a cellobiose molecular model. Through a series of ReaxFF- Molecular Dynamics (MD) simulations, the generation path of ethanol at the atomic level was studied. Because the molecular system has hydrogen bonding, force-bias Monte Carlo (fbMC) is mixed into ReaxFF to reduce the cost of calculation by reducing the sampled data. In order to ensure the reliability of the simulation, a model composed of 20 cellobioses and a model composed of 40 cellobioses were respectively established for repeated simulation in the range of 500–3000 K. The results show that insulating paper produced ethanol at extreme thermal fault, and the intermediate product of vinyl alcohol is the key to the aging process. It is also basically consistent with others’ previous experiment results. So it can provide an effective reference for the use of ethanol as an indicator to evaluate the aging condition of transformers.

show abstract

Section: Simulation Detailsmentioning

confidence: 84%

Section: Introductionmentioning

confidence: 99%

A Molecular Dynamics Study of the Generation of Ethanol for Insulating Paper Pyrolysis

Zhang

et al. 2020

Energies

Self Cite

View full text Add to dashboard Cite

show abstract

“…In view of the above issues, the existing researches reveal that dielectric frequency response might be used as an available approach to achieve the moisture analysis of polymer insulation materials [2,6,7,10,11]. Provided that the relevant parameter extracted from the analysis of FDS can be adopted to reflect the moisture content inside the cellulose insulation, the quantitative relationship between the extracted frequency dielectric response parameter and either ω DP (mc%) or k DP (mc%) can be established.…”

Section: The Improved Aging Kinetics Model By Employing Frequency Diementioning

confidence: 99%

“…Existing researches show that the degree of polymerization (DP) can be serviced as the most direct and effective indicator for reflecting the aging condition (mechanical strength) of polymer insulation [1][2][3]. Reviewing the published researches, we found out that the method for predicting (or measuring) the DP value of transformer polymer insulation consists of several prevailing approaches, such as the direct method (viscosity testing) [4] and indirect methods (including the Frequency Dielectric Spectroscopy (FDS) [5][6][7][8][9] technique, aging kinetics model [10][11][12], etc.). Although the viscosity test method is accurate enough, it is not appropriate for analyzing the field equipment due to its destructiveness.…”

Section: Introductionmentioning

confidence: 99%

A Modified Aging Kinetics Model for Aging Condition Prediction of Transformer Polymer Insulation by Employing the Frequency Domain Spectroscopy

et al. 2019

Self Cite

View full text Add to dashboard Cite

The aging kinetics model is of great interest to scholars since it is capable of describing the variation law between the degree of polymerization (DP) and the aging duration of transformer polymer (cellulose) insulation. However, it is difficult to determine the moisture content inside the transformer polymer insulation without destroying it, so that the model parameters cannot be confirmed. Such limitation greatly restricts its application. It is interesting to note that as long as the moisture content of the transformer polymer insulation could be characterized (replaced) by a certain feature parameter, the above issue will be solved naturally. The existing researches indicate that the Frequency Domain Spectroscopy (FDS) is sensitive to moisture. Consequently, the feature parameter that could characterize the moisture inside transformer polymer insulation (extracted from the FDS curve) can be used to report a modified aging kinetics model, which could perform the aging condition prediction of transformer polymer insulation under various test conditions, including aging duration, aging temperature, and initial moisture. In that respect, the average relative error of prediction results of prepared samples is equal to 7.41%, which reveals that the reported model might be serviced as a potential tool for the aging condition prediction of transformer polymer insulation.

show abstract

“…In the last decades, the state assessment methods of transformer polymer insulation materials based on the traditional chemical and electrical technique have been widely reported [5][6][7]. However, traditional methods require further research in the field test due to various limitations.…”

Section: Introductionmentioning

confidence: 99%

Correction for Polarization Current Curve of Polymer Insulation Materials in Transformers Considering the Temperature and Moisture Effects

et al. 2020

Self Cite

View full text Add to dashboard Cite

Depending on the study of the master curve technique, a temperature correction model for the polarization current of transformer polymer (cellulose) insulation, considering the effects of both moisture content (mc%) and temperature is proposed. In the current work, the shift factors of polarization current curves of samples with various moisture contents are extracted at different temperatures. Then, the variation law among the shift factor, test temperature, and moisture content are studied so as to establish the corresponding functional relationship. The findings reveal that the modified model derived from the above functional relationship could be employed to perform the temperature correction of oil-immersed polymer samples with various insulation states. Therefore, the proposed temperature correction model in this paper will promote the state assessment of the field transformer polymer insulation.

show abstract

Temperature correction to dielectric modulus and activation energy prediction of oil-immersed cellulose insulation

Cited by 59 publications

References 24 publications

A Molecular Dynamics Study of the Generation of Ethanol for Insulating Paper Pyrolysis

A Molecular Dynamics Study of the Generation of Ethanol for Insulating Paper Pyrolysis

A Modified Aging Kinetics Model for Aging Condition Prediction of Transformer Polymer Insulation by Employing the Frequency Domain Spectroscopy

Correction for Polarization Current Curve of Polymer Insulation Materials in Transformers Considering the Temperature and Moisture Effects

Contact Info

Product

Resources

About