Calculation of Surges Transmitted Between Transformer Windings Using the Coupled Circuit Model

Nitu, Maria Cristina; Duță, Marian

doi:10.1109/icate.2018.8551475

Cited by 2 publications

(5 citation statements)

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“…The transient phenomenon caused by the lightning impulse in the windings of a transformer is difficult to fit into a model, because both the amplitude and the frequency of the energizing voltage are variable over time. In addition, there is no consensus on the contribution of the magnetic core in determining the amplitude, the frequency of oscillation and the attenuation of the resulting signal in various parts of the windings [8][9][10][11][12][13][14].…”

Section: Overvoltages Transmitted Between the Windings Of Transformers Due To The Lightning Impulsementioning

confidence: 99%

“…The winding resistance is assigned the d.c. measured resistance value, which can be calculated according to the relation [8][9][10]:…”

Section: Determination Of the Electrical Circuit Parameters For The Low Voltage Windingmentioning

confidence: 99%

“…The second hypothesis assumes that path between the HV winding and the LV winding is equally filled by the lines of the magnetic field generated by the LV winding. These approximations are used for the calculation of the leakage reluctance between windings by using the following relations [8][9][10]:…”

Section: Determination Of the Magnetic Circuit Parametersmentioning

confidence: 99%

“…The magnetic core model implemented in the magnetic circuit coupled with the electrical circuit was proposed in the papers [9][10]…”

Section: The Model Of the Magnetic Core With Concentrated Parametersmentioning

confidence: 99%

“…To benefit from an optimal maintenance program, the active part of the transformer (magnetic core and windings) must be assessed as follows [1,[8][9][10][11][12][13][14][15]:…”

Section: Introductionmentioning

confidence: 99%

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Transitory Regimes and Their Effects on the Insulation of High Power Transformers

Duță¹,

Nitu²,

Nicola³

2020

AJECE

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Transformers are the most important pieces of equipment in the electricity transmission and distribution system.Their importance derives both from their high cost and from the fact that they ensure a proper operation of the national power system. The transitory regimes generated during the operation of transformers, such as the overvoltage caused by the lightning impulse and the transient currents when wiring the transformers result in mechanical stress, thermal stress and electrical stress in transformers. These stresses lead to the aging of the insulation system, to avoid possible damage or even the decommissioning of transformers, this paper presents analytical methods for determining the overvoltage transmitted between the windings of transformers due to the lightning impulse and the transient currents that occur when connecting the transformers. The studies were performed on two high power transformers: TTOS-OFAF of 40 MVA, 123 6.3 kV was used to determine the overvoltages that propagate at the windings of the transformer subjected to lightning impulse, and on TTOS-OFAF of 15 MVA, 10.5 / 6.3 kV was performed the study on the effects of the appearance of the connection current on the transformer insulation. The studied phenomena can have a negative impact on the transformer operation.. The results obtained have been validated by laboratory tests, and they can be used to determine the measures to be taken in order to avoid possible damages as of the time of the transformer implementation in the system.

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Section: Overvoltages Transmitted Between the Windings Of Transformers Due To The Lightning Impulsementioning

confidence: 99%

“…The winding resistance is assigned the d.c. measured resistance value, which can be calculated according to the relation [8][9][10]:…”

Section: Determination Of the Electrical Circuit Parameters For The Low Voltage Windingmentioning

confidence: 99%

Section: Determination Of the Magnetic Circuit Parametersmentioning

confidence: 99%

“…The magnetic core model implemented in the magnetic circuit coupled with the electrical circuit was proposed in the papers [9][10]…”

Section: The Model Of the Magnetic Core With Concentrated Parametersmentioning

confidence: 99%

“…To benefit from an optimal maintenance program, the active part of the transformer (magnetic core and windings) must be assessed as follows [1,[8][9][10][11][12][13][14][15]:…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations