Experimental procedure to obtain electromagnetic properties of A-36 low carbon steel plates utilized in transformers

Electromagnetic properties of low carbon steel, used for structural elements (tank, flitch plates and frames) of distribution and power transformers, are unknown to designers and manufacturers. Normally, steel manufacturers do not provide information on electromagnetic properties for low carbon steels. These properties are important to determine the power losses in the structural elements which have an impact in the temperature of these elements. Generally, designers use some estimations of low carbon steel properties. Hence, knowledge of the low carbon steel properties that are close to the real ones will definitely help to have better designed transformers, as it will give designers the opportunity to choose the steel that produces lower losses and consequently lower temperature in structural parts. This paper presents an experimental procedure to obtain electromagnetic properties for A-36 low carbon steel used to manufacture structural elements of distribution and power transformers. The Epstein frame method is applied to obtain the electromagnetic properties for A-36 carbon steel plates. Magnetization and power loss curves were obtained in laboratory tests. This paper provides electromagnetic properties for this low carbon steel. This is valuable information for transformer designers, as the real magnetic saturation and real stray losses produced in structural elements that use this material can be calculated.