Experimental Verification Of Three-Dimensional Analysis Of Leakage Magnetic Fields In Large Power Transformers

In a previous paper by the first author, a three-dimensional analysis for the calculation of the leakage magnetic field in power transformers was presented. The experimental verification of this analysis is the subject of this paper. Extensive comparisons between calculated and measured values of flux densities in the winding of an experimental three-phase shell form transformer are presented. The results as well as the agreements and deviations obtained are discussed in light of the ultimate objective of accurate determination of various transformer performance parameters. The close agreements obtained verify the accuracy of the method of calculation as well as the validity of the experimental and measuring techniques. The results also demonstrate that accurate determination of losses, circulating currents, short circuit forces, impedance, shielding requirements and other performance parameters is possible only through three-dimensional calculations of the leakage magnetic field in the transformer.