Frequency Characteristics of Single-Phase Two-Winding Transformers Using Distributed Parameter Modeling

Al-Fuhaid, A.S.

doi:10.1109/mper.2001.4311489

Cited by 7 publications

(8 citation statements)

References 8 publications

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“…In Nakamura et al and Alfuhaid, transformer models described by means of current and voltage equations known from the circuits theory were presented. The model tests were carried out in a frequency range up to about 100 kHz.…”

Section: Introductionmentioning

confidence: 99%

“…The model from Nakamura et al referred to the transformer, in which windings were orthogonal and a description of thermal losses was presented by means of a resistive network, omitting a description of windings. In Alfuhaid, a single‐phase transformer model was proposed to determine its resonant frequency. This model contains descriptions of thermal phenomena in the core and windings, but it does not contain a description of mutual thermal couplings between the core and windings.…”

Section: Introductionmentioning

confidence: 99%

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Modelling characteristics of the impulse transformer in a wide frequency range

Górecki

Godlewska

2020

Circuit Theory & Apps

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In the paper, a new compact electrothermal model of the impulse transformer is proposed. This model has a form of a subcircuit dedicated for SPICE and could be used for low power impulse transformers applicable in switch-mode power supplies used in electronics. It takes into account simultaneously electric, thermal, and magnetic phenomena occurring in the considered device and describe nonidealities of the core and windings. The form of the elaborated model and analytical dependences describing all its components are presented. Correctness of this model is verified experimentally in a wide range of frequency and load resistance for selected constructions of transformers. Satisfactory agreement between the results of computations and measurements is obtained K E Y W O R D S compact electrothermal models, impulse transformer, modelling, SPICE

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Modelling characteristics of the impulse transformer in a wide frequency range

Górecki

Godlewska

2020

Circuit Theory & Apps

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“…Transformer winding equivalent circuits are traditionally used to examine the voltage surge distribution in the transformer windings [7][8][9]. Several studies have been carried out to examine the transient voltage surge propagations through simulations and experimental setups [10][11][12][13][14][15][16].…”

Section: Introductionmentioning

confidence: 99%

Effect of shield placement for transient voltage mitigation due to switching surges in a 33/11 kV transformer windings

et al. 2020

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This study presents an investigation on the effect of shield placement for mitigation of transient voltage in a 33/11 kV, 30 MVA transformer due to Standard Switching Impulse (SSI) and Oscillating Switching Impulse (OSI) surges. Generally, the winding and insulation in transformers could experience severe voltage stress due to the external impulses i.e. switching events. Hence, it is important to examine the voltage stress and identify the mitigation action i.e. shield placements in order to reduce the adverse effect to the transformer windings. First, the resistances, inductances, and capacitances (RLC) were calculated for disc type transformer in order to develop the winding RLC equivalent circuit. The SSI and OSI transient voltage waveforms were applied to the High Voltage (HV) winding whereby the transient voltages were simulated for each disc. The resulting voltage stresses were mitigated through different configurations of electrostatic shield placements. The resonant oscillations generated due to switching surges were analysed through initial voltage distribution. The analyses on the transient voltages of the transformer winding and standard error of the slope (SEb) reveal that the location of shield placement has a significant effect on the resonant switching voltages. The increment of the shield number in the windings does not guarantee optimize mitigation of the resonant switching transient voltages. It is found that the voltage stress along the windings is linear once a floating shield is placed between the HV and Low Voltage (LV) windings of the disc-type transformer under the SSI and OSI waveforms. These findings could assist the manufacturers with appropriate technical basis for mitigation of the transformer winding against the external transient switching overvoltage surges.

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“…The overvoltage signal has broad-spectrum characteristics, which makes it possible to be used as an exciting signal for diagnosis of permanent winding faults [26]. Moreover, compared with traditional FRA, the overvoltage signal has greater amplitude and can avoid the insulation failure caused by signal injection.…”

Section: Introductionmentioning

confidence: 99%

Comparison of Impulse Wave and Sweep Frequency Response Analysis Methods for Diagnosis of Transformer Winding Faults

Yang

Yong

2017

Energies

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Abstract:Monitoring of winding faults is the most important item used to determine the maintenance status of a transformer. Commonly used methods for winding-fault diagnosis require the transformer to exit operation before testing and an external exciting signal, whether the transformer is malfunctioning or not. However, if an overvoltage signal can be regarded as a broadband excitation source for fault diagnosis, then the interference caused by signal injection can be eliminated without the need for additional pulse or impulse signals. In this paper, a tapped transformer is designed and test platforms are built to compare winding diagnoses using the impulse wave and sweep frequency response analysis methods by recording voltage responses on both the high-and low-voltage sides and calculating the respective transfer functions. Based on comparison of statistical indicators, it is found that the sensitivities of both methods are similar for detecting conditions of winding-ground and winding-interlayer short circuits. It is concluded that it is feasible to use a transient overvoltage monitoring system for winding-fault diagnosis.

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Frequency Characteristics of Single-Phase Two-Winding Transformers Using Distributed Parameter Modeling

Cited by 7 publications

References 8 publications

Modelling characteristics of the impulse transformer in a wide frequency range

Modelling characteristics of the impulse transformer in a wide frequency range

Effect of shield placement for transient voltage mitigation due to switching surges in a 33/11 kV transformer windings

Comparison of Impulse Wave and Sweep Frequency Response Analysis Methods for Diagnosis of Transformer Winding Faults

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