Study on electromagnetic-force characteristics of silicon steel sheet and vibration noise of transformer under different tensile and compressive stresses

In this paper, the electromagnetic, vibration, and noise performance of transformers under different tensile and compressive stresses is studied. First, the magnetic properties of silicon steel sheets in transformer cores under different tensile and compressive stresses are studied. The B–H curve, B–P curve, and permeability curve of silicon steel sheets under different tensile and compressive stresses are presented. Second, the magnetostrictive characteristics of silicon steel sheets are tested and analyzed, and the butterfly curve and magnetostrictive single-valued curve of silicon steel sheets are presented. Based on the test results of magnetic and magnetostrictive properties of silicon steel sheets, the electromagnetic performance and vibration noise of a 3 kVA transformer are simulated and analyzed using COMSOL finite element software. In the simulation process, the influence of different tensile and compressive stresses on the performance of silicon steel sheets in transformer cores is considered. Finally, an experimental platform for transformer vibration and noise without compressive stress is built, and experimental research on vibration acceleration and noise of transformers under 2 and 6 MPa compressive stresses is carried out, providing a new perspective for the electromagnetic-vibration and noise analysis of transformers.