In this thesis, the dynamic properties of the mechanic structure of Power Supply for an Industrial Application, an Alstom company product, are considered. A finite element model of the Power Supply mechanic structure have been generated with the aid of the MSC Marc software. Based on the FE model; modal analysis have been carried out and the eigenfrequencies and eigenmodes for the FE model have been calculated in a suitable frequency range. Relevant frequency response functions for the FE model have been produced using dynamic harmonic analysis. To validate and update the FE model, experimental modal analysis have been carried out on a Power Supply. For the experimental modal analysis the MIMO method the polyreference least-squares complex exponential method have been used. Based on the updated FE model some modified Power Supply designs are suggested with improved dynamic properties in an adequate frequency range.