9Boruckis, Boczar T, Cichon A. Technical possibilities of reducing the sound pressure level emitted into the environment by a power transformer[ J ]. Archives of Acoustics,2011, 36 ( 1 ) : 49 - 56.
10Patil S, Krady G K, Wesley K. Effect of load - generated transform- er noise in a substation [ J ]. European Transactions on Electrical Power, 2011, 21 ( 1 ) :596 -607.