Abstract: Provided is a brace apparatus for a transformer tank and a method for determining the length thereof. The brace apparatus is mounted on a transformer tank so as to reinforce the transformer tank. The brace apparatus has a brace main body forming the exterior thereof, and in order to block the occurrence of resonance in an inner space of the brace main body, the length of the brace main body is set to be at a value at which resonance does not occur in the inner space, or a partition plate is provided to the brace main body so as to block the occurrence of resonance. In present invention, the length of the brace apparatus may be set by means of a simple configuration, thereby enabling the prevention of noise from occurring due to resonance.

Abstract: Provided is a transformer having a noise reducing means. The transformer includes: an iron core (P), which is formed by stacking a plurality of steel sheets, and has stepped parts (S) formed at a portion thereof with different widths; and the noise reducing means provided at the stepped parts (S) so as to increase coupling force among the plurality of steel sheets. The noise reducing means includes: pressing bars (30) mounted on the stepped parts (S) of the iron core (P), and having plane-shaped horizontal pressing surfaces (31) in the direction in which the steel sheets are stacked; and a binding (90) for surrounding the outer surface of the iron core (P) including the pressing bars (30), so as to press the pressing bars (30) in the stacking direction of the steel sheets.