Audible Noise of Power Transformers

In the past few years, much emphasis has been put on audible noise of power transformers. Control of noise levels of such transformers without seriously affecting other important characteristics of the transformers is an important challenge to manufacturers. Sources of audible noise in power transformers, its attenuation and transmission, and the effect on designs are considered. Some characteristics of such noise are presented and methods of reducing noise levels are discussed. Power transformer noise problems confronting the manufacturer of such apparatus are discussed in relation to the over-all transformer design.