Deriving an Equivalent Circuit of Transformers Insulation for Understanding the Dielectric Response Measurements

Saha, Tapan Kumar; Purkait, P.; Muller, F.

doi:10.1109/tpwrd.2004.835436

Cited by 225 publications

(220 citation statements)

References 15 publications

Supporting

Mentioning

211

Contrasting

Unclassified

Order By: Relevance

“…Thus, the dielectric can be equivalent to complex capacitance [25]. When AC voltage U (ω) with an angular frequency of 2πf is applied to both ends of the dielectric, the through-current of the dielectric is:…”

Section: Theoretical Basismentioning

confidence: 99%

A New Method for Evaluating Moisture Content and Aging Degree of Transformer Oil-Paper Insulation Based on Frequency Domain Spectroscopy

Xia

Gao

et al. 2017

Energies

View full text Add to dashboard Cite

Abstract:The condition of oil-paper insulation is closely related to the life expectancy of a transformer. The accurate results of oil-paper have not been obtained due to the impact of influencing factors. Therefore, in order to improve the evaluation accuracy of oil-paper insulation, in this paper, oil-paper samples which were prepared with different aging and moisture content were analyzed by frequency domain spectroscopy (FDS). Results show that when the moisture content is less than 2%, the range of 10 1~1 0 3 Hz is mainly affected by moisture and aging has little effect. However, with the increase of moisture content, the effect of aging degree on this band became increasingly prominent. S m , which represents the integral value from 10 −1 to 10 −3 Hz, and S DP , which represents the integral value from 10 1 to 10 3 Hz, were extracted as characteristic parameters of moisture content and aging degree respectively. Compensation factors γ which represents the influence ratio of moisture on S DP and φ which represents the influence ratio of aging on S m were introduced to compensate for the influence of moisture content and aging degree on characteristics respectively. Then, a new method was proposed to evaluate the condition of oil-paper based on compensation factors. Through this method, the influence in characteristics can be eliminated by the obtained actual compensation factors, thus distinguishing the internal influence between moisture content and aging degree on FDS. Finally, this method was verified by field test.

show abstract

Section: Theoretical Basismentioning

confidence: 99%

A New Method for Evaluating Moisture Content and Aging Degree of Transformer Oil-Paper Insulation Based on Frequency Domain Spectroscopy

Xia

Gao

et al. 2017

Energies

View full text Add to dashboard Cite

show abstract

“…Time domain current measurements [2,6,10,16] Slow polarization processes in a dielectric material can be analyzed using polarization and depolarization current measurements. When a fixed dc voltage (U 0 ) is applied across a completely discharged material the resultant polarization current due to conduction and slow polarization processes can be written as, ( )…”

Section: Theory On Analysis Of Polarization Based Measurementsmentioning

confidence: 99%

“…1. The method of evaluating model parameters can be found in [2]. These model parameters were used in the developed expert system [6] for estimating moisture content and oil/paper conductivity.…”

Section: Theory On Analysis Of Polarization Based Measurementsmentioning

confidence: 99%

“…6 illustrates the frequency dependent loss (C") and frequency dependent loss factor corresponds to measurements A1. 2 (a) (b) Fig. 6.…”

Section: B Fds Response Of Non-equivalent Unitsmentioning

confidence: 99%

“…Commercially available as well as locally manufactured PDC measuring systems have been used in different studies [10,11]. Modeling PDC data with circuit parameters is one of the most common techniques utilized in insulation condition assessment [2]. It has been widely accepted that a change in oil conductivity and moisture in the insulation has an immense effect on the elements of the RC circuits.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations