Performance of single-phase transformer cores assembled from consolidated stacks of electrical steels

Marketos, P.; Meydan, Turgut; Snell, D.

doi:10.1016/s0304-8853(02)00910-1

Cited by 5 publications

(5 citation statements)

References 4 publications

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“…Five 10 MVA/69/13.8 kV mineral‐oil‐immersed single‐phase core‐type transformers were tested to measure the core losses under nominal excitation in laboratory according to international standards . These transformers were built with the core configuration described in . The core of each transformer was made entirely of M‐6 steel, M‐5 steel, M‐4 steel, M‐3 steel, and TRAN‐COR H0 steel, respectively.…”

Section: Finite Element Simulationsmentioning

confidence: 99%

“…The methodology to combine steels, reported in and , is extended in this work to cores with joints at 90°. The construction of power transformers with combined cores is facilitated with the use of the butt‐lap core configuration shown in (Figure ), where joints at 90° are employed. This configuration consists of single laminations placed in such a way that they overlap each other in alternate layers, leading to small power losses.…”

Section: Introductionmentioning

confidence: 99%

“…This configuration consists of single laminations placed in such a way that they overlap each other in alternate layers, leading to small power losses. Core joints at 90° only involve a 5% increase in the core losses, but they can be built rapidly (typically 25 times faster), which is an important economical consideration for transformer manufacturers . Moreover, the increased losses of the butt‐lap configuration with joints at 90° are offset by the combination of electrical steels.…”

Section: Introductionmentioning

confidence: 99%

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Loss reduction by combining electrical steels in the core of power transformers

Magdaleno-Adame¹,

Melgoza-Vázquez

Olivares-Galván

et al. 2015

Int. Trans. Electr. Energ. Syst.

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This paper analyzes a practical methodology to assemble/combine commercial electrical steels in a singlephase core-type power transformer. The main advantage of these electrical steel combinations is the reduction of core losses and their associated cost, without compromising the integrity of the transformer. An explanation of the improved performance with a combination of electrical steels in core-type power transformers is presented in this paper. The steel combinations are studied using transient, nonlinear, 3D finite-element simulations, with proper calculation of core losses. Electrical steels in the core are modeled using their magnetization curves. Five commercial electrical steels are considered: four conventional steels (M-6, M-5, M-4, and M-3) and a laser-scribed electrical steel (TRAN-COR H0). From the simulations, the attainable reduction in core losses by means of steel combinations is determined. Results from the simulations are compared with laboratory tests. Finally, 3D finite element static thermal formulations are used to rule out hot spots in the cores made of electrical steel combinations.

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Section: Finite Element Simulationsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Loss reduction by combining electrical steels in the core of power transformers

Magdaleno-Adame¹,

Melgoza-Vázquez

Olivares-Galván

et al. 2015

Int. Trans. Electr. Energ. Syst.

View full text Add to dashboard Cite

show abstract

“…The performance of a transformer core depends directly on the core's materials and construction . When laminated transformer cores (which can be stacked in any alphabetical order, such as E‐I, C‐I, or U‐T, and can be ordered using 2 stacked pieces) are manufactured, core sheets are drilled in certain regions.…”

Section: Introductionmentioning

confidence: 99%

“…These holes are necessary for tailoring transformer‐core designs, even though the holes deteriorate the cores' magnetic properties. However, although various studies investigated core manufacturing, proper hole positions and the impacts of holes on transformer designs in stacked transformer cores were still remained uncertain. To fill this research gap, spark erosion was used to pierce laminated transformer‐core sheet specimens and form circles with various diameters at certain locations on the sheets.…”

Section: Introductionmentioning

confidence: 99%

Numerical and experimental analyses of the deterioration in magnetic flux density distribution on perforated transformer core steels

Güneş

2018

Int J Numerical Modelling

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The holes in transformer core sheets are necessary for tailoring transformer‐core designs even though they cause more or less deterioration in the magnetic properties. With using spark erosion, specimens were pierced as a circle shape at certain locations and diameters to compare their effects to the magnetic properties by means of hysteresis curves, Magneto‐optical Kerr imaging, and finite element method. It was found that piercing the middles and corners of sheets at regular intervals dropped the sheets' relative permeabilities to ranges of 28% to 70%. Additionally, significant increments in power losses, from 0.8 to 2.54 W/kg at 50 Hz, depending on increases in hole diameters, were noted. These effects did not occur in a non‐pierced sample. Furthermore, considering all possible scenarios based on hole diameters and locations, laminated transformer‐core sheets were simulated to study distributions of flux lines, flux densities, and magnetic forces using 2‐dimensional static magnetic analyses. Holes in the sheets and the holes' proximities to each other were noted using magneto‐optical Kerr microscopies. Kerr images and diagrams of flux propagation from the simulation were individually compared to consider how the sheets flux distributions were influenced by varying the physical properties of the holes. The cases' effects on basic transformer cores were also investigated using 2‐dimensional static analyses.

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Effects of Laser-Cutting and Spark Erosion Techniques and Heat Treatment on the Magnetic Properties of Grain-Oriented Transformer Steels

Güneş

2018

J Supercond Nov Magn

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Performance of single-phase transformer cores assembled from consolidated stacks of electrical steels

Cited by 5 publications

References 4 publications

Loss reduction by combining electrical steels in the core of power transformers

Loss reduction by combining electrical steels in the core of power transformers

Numerical and experimental analyses of the deterioration in magnetic flux density distribution on perforated transformer core steels

Effects of Laser-Cutting and Spark Erosion Techniques and Heat Treatment on the Magnetic Properties of Grain-Oriented Transformer Steels

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