1. Reduce vibration source noise

(1) Choosing high magnetic permeability materials with low magnetic elasticity, such as 30ZHl20 silicon steel sheets, can reduce noise by 4-5 dB (A) compared to using other materials of silicon steel sheets.

(2) Lowering the magnetic density of the iron core can reduce noise. For every 0.1T decrease in magnetic density, it can decrease by 2-3dB (A). After reducing the magnetic flux density, the cross-sectional area of the iron core, equivalent capacity of the transformer, and cost all increase accordingly, which is uneconomical in terms of cost. Therefore, the decrease in magnetic density should not exceed 10% of the standard magnetic density.

(3) Improve and reduce the seam of the iron core. The iron core adopts multi-stage seams. Choosing a multi-stage joint iron core has lower no-load noise compared to a two-stage joint, which can reduce noise by 4-5 dB (A). This is because the use of multi-level (four level and above) seams results in a more uniform distribution of magnetic flux at the seams, which greatly reduces the magnetic density in the air gap and reduces the noise caused by magnetic attraction at the seams. In addition, reducing the seam can decrease the amplitude, reduce the excitation capacity and current of the transformer, and significantly reduce the sound power, which can reduce the no-load noise by 4-5dB (A).

(4) Avoid and reduce the mechanical impact on cold-rolled silicon steel sheets during processing and production, otherwise it will increase the magnetic elasticity of the silicon steel sheets and add noise from the iron core.

(5) Applying epoxy adhesive or polyester adhesive on the end face of the iron core can add tension binding to the surface of the iron core, and also reduce the magnetic elasticity and noise.

2. In terms of absorbing sound energy and reducing vibration

(1) Part of the noise generated by the iron core is transmitted through the bottom of the box and the foundation. If a buffer is added between the body and the fuel tank or between the fuel tank and the foundation, it can attenuate the sound through the buffer. Anti vibration rubber pads can be placed at the foot of the iron core and between the magnetic shield and the box wall, so that when the oscillation of the iron core and magnetic shield is transmitted to the oil tank, the connection changes from a rigid connection to an elastic connection, thereby reducing oscillation, avoiding resonance, and reducing noise. It can reduce noise by 1-2dB (A).

(2) Strengthening the iron inside the fuel tank with sound insulation materials can absorb a portion of the energy generated by the tank oscillation, thereby achieving the goal of reducing the body noise by 2-3dB (A).

Article source: Transformer silicon steel sheethttp://www.cheungshun.com/