Research on key technology of low noise transformer and its application on 110kV transformer

Aiming at the problem of 110kV transformer operation noise exceeding the standard, this study systematically analyzes the noise mechanism under the action of electromagnetic-mechanical-acoustic multi-physical field coupling, and puts forward a multi-objective optimization design method based on finite element simulation. By constructing a coupled electromagnetic-mechanical-acoustic field model, the nonlinear influence of rated capacity, magnetic flux density and other parameters on the noise is revealed, which breaks through the limitations of the traditional single physical field simulation. The composite noise reduction structure of double-layer magnetic shielding sandwiched by corrugated paperboard is innovatively proposed, combining the dual mechanisms of sound absorption and vibration isolation, and the simulation verifies that its noise reduction effect is significantly better than that of the traditional single-layer magnetic shielding scheme. The study further quantifies the threshold values of passive noise reduction measures such as clamping force optimization (0.11-0.13 MPa is the best range) and core material replacement, and amends the applicable boundaries of engineering empirical formulas, which provides theoretical support and engineering guidance for the standardized design of low-noise transformers.