This paper presents the effects of magnetostriction of core loss and sound level on the design of power transformers and the results of analysis via the particle swarm optimization (PSO) method. The core losses and the magnetostrictive forces in the ferromagnetic cores of transformers of various capacities, ranging from 15 MVA to 120 MVA, were found to be significantly different from each other, as shown in Figure 1. Further, core loss was approximately proportional to capacity and core volume. However, the sound level performance was not linear because of the squareness ratio (). This study utilized three types of soft core material: 30ZH105, 27ZH100 (Japan), and 27PH100 (Korea). The hysteresis loop and magnetostriction were measured for various magnetic parameters. It was found that extremely high does not directly affect core loss. Whenwith respect to the sound level is high, the experimental and design values are almost the same. The PSO method simulation results for transformers with several capacities, with respect to sound level and core loss performance, were analyzed and compared with experimental values, as shown in Figure 2.

References:

1 L. Bernard, , et. al., “Effect of stress on switched reluctance motors: A magnetoelastic finite-element approach based on multiscale constitutive laws,” IEEE Trans. on Magnetics, vol. 47, no. 9, pp. 2171–2178, 2011.
2 Chang-Hung Hsu, et. al., “Reduction of vibration and sound-level for a single-phase power transformer with large capacity,” IEEE Trans. on Magnetics, vol. 51, no. 11, pp. 8403204-1- 4, 2015.