Analysis of Very Fast Transients in Layer-Type Transformer Windings

Popov, Marjan; Sluis, L. van der; Smeets, R.P.P.; Roldan, JB

doi:10.1109/tpwrd.2006.881605

Cited by 120 publications

(58 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Capacitance between core and end turns of layers was calculated considering parallel plate capacitor model assuming that only the end turns of each layer contribute for capacitance of this nature [7].…”

Section: Capacitance Between Core and End Turnsmentioning

confidence: 99%

Mitigation of lightning surge stresses in the high voltage windings of distribution transformers by introducing an electrostatic shield

Wijayapala

Karunananda²

2015

Engineer

View full text Add to dashboard Cite

Abstract:The Medium Voltage (MV) Electricity Distribution Networks are frequently exposed to lightning and it is the main suspected reason for distribution transformer failures. Appreciable number of transformer failures occur due to insulation failures notably at points near line ends. The short rise time of a surge prompted by a lightning impulse can cause deterioration in the insulation and ultimately lead to a dielectric breakdown. The voltage distribution along transformer High Voltage (HV) winding becomes non-linear under surge conditions due to the capacitive-inductive currents. This research focuses on the possibility of neutralizing this effect with the aid of an electrostatic shield inserted in to the HV winding.Comparison of the behaviour of the winding under surge conditions with and without electrostatic shield requires appropriate transient models suitable for simulations. The necessary calculations required for this purpose were carried out and the proposed models are presented. The simulations were carried out with PSCAD software and the results are included in this paper. The oscillatory nature due to the combined effect of capacitors and inductors is observed in the wave tail region and some of the peaks created have potentials exceeding the peak potential of the surge waveform as well.The proposed transformer model have a definite positive effect compared with the available model as the results obtained by simulations clearly reveal the reduction of the stresses on the transformer HV windings when a shield is used.

show abstract

Section: Capacitance Between Core and End Turnsmentioning

confidence: 99%

Mitigation of lightning surge stresses in the high voltage windings of distribution transformers by introducing an electrostatic shield

Wijayapala

Karunananda²

2015

Engineer

View full text Add to dashboard Cite

show abstract

“…VFTO is the phenomenon of transient overvoltage generated during switching operation characterized by very short rise-time of 4 to 100 ns and has been covered by various literatures [3,[12][13][14][15][16][17][18][19][20][21][22]. The phenomenon is particularly significant during Disconnect Switch (DS) operation due to multiple-restriking in the DS due to lack of arc-suppressing chamber.…”

Section: Switching Surges and Very Fast Transient Overvoltage (Vfto)mentioning

confidence: 99%

Power System Protection Design for NPP

Lee¹,

Chen²

2012

Nuclear Power- Practical Aspects

View full text Add to dashboard Cite

“…There are numerous studies addressing the time-and frequency-domain analyses of power transformers such as those documented in [1][2][3][4][5][6][7][8][9][10][11][12][13][14][16][17][18][19]. Special attention has been devoted to the frequency, and the complex s-domain approaches.…”

Section: Introductionmentioning

confidence: 99%

The Transient Response and Frequency Characteristics of Power Transformers Having Internal Winding Faults

Saied¹

2017

IJPER

View full text Add to dashboard Cite

Abstract.A procedure and a corresponding computer program for determining the transient response of a transformer winding under faulty conditions are presented. The model is based on distributed-parameter analysis and is capable of taking the non-uniform distributions of the winding's inductances and capacitances into account. It will be demonstrated that snapshots of the instantaneous voltage and current distributions along the winding at any point in time, as well as the energization response to standard input stimuli can be efficiently utilized for monitoring the winding's conditions. An auxiliary function is suggested for simulating the different kinds, severities and locations of the internal faults. Results for both solidly-earthed and isolated transformer neutral points are given. It will be indicated that the source current includes useful information for assessing the winding's integrity and recognizing the type and location of eventually existing faults. It is believed that the presented approach can assist in providing helpful database for the condition monitoring of power transformers.

show abstract

Analysis of Very Fast Transients in Layer-Type Transformer Windings

Cited by 120 publications

References 21 publications

Mitigation of lightning surge stresses in the high voltage windings of distribution transformers by introducing an electrostatic shield

Mitigation of lightning surge stresses in the high voltage windings of distribution transformers by introducing an electrostatic shield

Power System Protection Design for NPP

The Transient Response and Frequency Characteristics of Power Transformers Having Internal Winding Faults

Contact Info

Product

Resources

About