M. Soltanmohammadi - Zangan Distribution Transformer Co., Zanjan, Iran
S. Taghiloo - Manager in execution, Distribution Transformer Co., Zanjan , Iran.
S. Paknia - Technical manager, Distribution Transformer Co., Zanjan, Iran.

Cast resin transformers can be installed indoor adjacent to theresidential areas since they are clean and safe compared to theconventional oil transformers. But the noise is an avoidable problem incast resin transformers as it is the case for all other types oftransformers. Minimization of the noise level has biological importance.It is known that the core of transformers is the main source of the noise.In this paper, experimental and numerical investigations are performedfor a large number of Iran-Transfo fabricated cast resin transformers, toevaluate the effective parameters on the overall mean sound level of thetransformers. The noise level of each sample is measured according toIEC60651 criteria. Numerical simulation is done by the use of ANSYSsoftware. The Pearson factor shows that the first natural frequency hasrelation with the noise level. To evaluate the mean noise level of thetransformers prior to fabrication in design phase, a correlation betweenthe numerical and experimental values is proposed. In this way, themean noise level can be approximated by knowing the dimensions andthe first natural frequency of the core as the main effective parameters.Numerical results are in good agreement with experimental outcomes. Itis also deduced that the proposed equations can be used to approximatemean noise level in design phase prior to manufacturing with 10%tolerance.

ANSYS; FEM; Mean noise level; Cast resin transformers; Pearson factor