Developing an Accurate Load Noise Formula for Power Transformers

A thorough investigation of the design parameters influencing the load noise generated by power transformers is performed. The investigation is done through evaluating the calculated noise by using an advanced vibro-acoustic model and benchmarking it against measured sound levels of transformers with different ratings and designs. The design parameters are weighted based on their level of influence on the generated noise and are used to drive a detailed load noise formula (d-LNF). The d-LNF is further developed by weighting the most relevant parameters to drive a simplified LNF. Both formulas have proven their reliability in calculating the load noise and therefore, they have been used in the daily designs to optimize for low noise transformers. However, the advantage of the LNF is that it can be easily exchanged between transformer manufacturers and utilities as it involves the main electrical design data without details about the designs of winding, shields, tank and insulations.