Comparison of Thermal Loads a Single-Phase Transformer With a Laminated Magnetic Core

Abstract

A promising direction for improving transformers is to transform structures and design of the electromagnetic systems. Rod and armored laminated magnetic cores of single-phase transformers are made of anisotropic electrical steel. Such magnetic circuits contain, respectively, four and six angular zones of magnetic flux direction change relative to the texture of steel with laminated joints, which causes significant additional losses. Improvement of single-phase transformers is possible by replacing named planar systems with a symmetrical radial electromagnetic system with three angular zones of three-rod magnetic circuit. Based on the method of invariant objective functions with dimensionless optimization components and universal relative controlled variables, mathematical models for determining the average thermal loads of the windings of the named variants of oil single-phase transformers with voltage up to 1000 V have been developed. The possibility of checking and comparing the thermal design constraint during the optimization of transformer is provided. The advantages of the radial electromagnetic system of a single-phase transformer with a three-rod magnetic circuit are shown.