Electric and Magnetic Field Analysis for a 34.5 kV Transformer Under Composite Voltage Conditions: COMSOL Multiphysics Simulation

Abstract

Transformers are one of the basic components of electrical power systems and play a critical role in energy conversion. However, overvoltages and environmental stresses can cause failures in transformer insulation systems. These failures can negatively affect reliability by reducing the lifetime of insulation systems and can lead to serious losses in power transmission. Moreover, sudden failures increase economic costs and reduce the overall efficiency of power systems. For this reason, a 3 MVA, 34.5 kV dry-type distribution transformer was modeled using COMSOL Multiphysics software. Based on IEC 60076-3 and IEC 60060-1:2010 standards, a lightning impulse voltage with an amplitude of 170 kV and nominal operating voltage were simultaneously applied to the modeled transformer. Electric field strength, magnetic flux density, and electric potential distributions were analyzed under composite voltage conditions. Under these conditions, the effects of electrical stress on the insulation strength are discussed in detail. The results obtained show the negative effects of composite voltage signal components on the insulation performance of the transformer and potential areas for improvement.

Keywords

• Composite voltage
• Electric field analysis
• Magnetic flux density
• COMSOL Multiphysics
• Lightning impulse voltage

Kompozit Gerilim Koşulları Altında 34,5 kV’ luk Transformatörün Elektrik ve Manyetik Alan Analizi: COMSOL Multiphysics Simülasyonu

Abstract

Transformatörler, elektrik güç sistemlerinin temel bileşenlerinden biri olup enerji dönüşümünde kritik bir rol oynamaktadır. Ancak, aşırı gerilimler ve çevresel zorlanmalar, transformatörlerin yalıtım sistemlerinde arızalara yol açabilmektedir. Bu arızalar, yalıtım sistemlerinin ömrünü kısaltarak güvenilirliği olumsuz yönde etkileyebilir ve enerji iletiminde ciddi kayıplara yol açabilir. Ayrıca, ani arızalar ekonomik maliyetleri artırırken, güç sistemlerinin genel verimliliğini de düşürmektedir. Bu sebeple, çalışma kapsamında 3 MVA gücünde, 34,5 kV’luk kuru tip bir dağıtım transformatörü, COMSOL Multiphysics yazılımı kullanılarak modellenmiştir. IEC 60076-3 ve IEC 60060-1:2010 standartları temel alınarak, modellenen transformatöre genliği 170 kV olan yıldırım darbe gerilimi ile nominal işletme gerilimi eş zamanlı olarak uygulanmıştır. Karma gerilim koşulları altında elektrik alan şiddeti, manyetik akı yoğunluğu ve elektrik potansiyeli dağılımları analiz edilmiştir. Bu koşullar altında yalıtım sistemlerinde meydana gelen elektriksel zorlanmanın yalıtım dayanımı üzerindeki etkileri ayrıntılı olarak ele alınmıştır. Elde edilen sonuçlar, karma gerilim işareti bileşenlerinin transformatörün yalıtım performansı üzerindeki olumsuz etkilerini ve potansiyel iyileştirme alanlarını ortaya koymaktadır.

Keywords

• Karma gerilim
• Elektrik alan analizi
• Manyetik akı yoğunluğu
• COMSOL Multiphysics
• Yıldırım darbe gerilimi

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