Prediction of Far Field Sound Radiation from Transformers

A method has been presented for predicting from surface vibration data the sound radiated by a power transformer. The technique, which is well-suited to numerical computations, is based on modeling the transformer tank as a concatenation of rigid right-angled wedges. The vibration data may be the results of measurements or of auxiliary calculations. The variation of the radiation pattern with respect to distance and angle can be investigated with an accuracy that is limited primarily by the spacing of surface measurement points. The method has been verified in a field test using controlled excitation and in a check against previously obtained analytical and experimental results. The calculation of sound radiation patterns from surface acceleration measurements made on a production line transformer operating under simulated load conditions indicate the usefulness of this technique in predicting the noise performance characteristics of power transformers.