TRANSFORMER NOISE PERFORMANCE DIAGNOSIS METHOD AND NOISE REDUCTION METHOD

A transformer noise performance diagnosis method comprises: a step of acquiring a frequency spectrum of a noise of a stacked iron core 21 included in a transformer, the stacked iron core 21 being formed by stacking electrical steel sheets; a step of, for excitation vibration calculation of the stacked iron core 21, determining transverse elasticity moduli in two planes each including a stacking direction of the stacked iron core 21; a step of performing the excitation vibration calculation for the stacked iron core 21 using a constitutive equation that includes an elasticity matrix including the determined transverse elasticity moduli as elements and acquiring a frequency spectrum of an excitation vibration of the stacked iron core 21; a step of calculating a difference between the spectrum of the excitation noise of the stacked iron core 21 and the frequency spectrum of the excitation vibration of the stacked iron core 21 as a difference spectrum; and a step of diagnosing noise performance of the transformer based on the difference spectrum.