Rolled welding type oil tank magnetic shielding structure and manufacturing method thereof

Abstract

The invention relates to a rolled welding type oil tank magnetic shielding structure and a manufacturing method thereof. The rolled welding type oil tank magnetic shielding structure is characterizedin that end sealing plates are arranged on peripheries of two ends of a single rolled magnetic shield, side clamping plates are arranged on the peripheries of two sides of the single rolled magnetic shield, two ends of the side clamping plates on each side are connected with the end sealing plates on the peripheries of the two ends of the single rolled magnetic shield respectively, the single rolled magnetic shield is clamped and fixed through the side clamping plates and the end sealing plates, a middle pulling plate is arranged below the single rolled magnetic shield and is connected with the single rolled magnetic shield and the side clamping plates on the two sides of the single rolled magnetic shield respectively, or the middle pulling plate is connected with the single rolled magnetic shield and the end sealing plates at the two ends of the single rolled magnetic shield respectively, the single-piece rolled magnetic shield, the middle pulling plate, the side clamping plates and the end sealing plates form a single-piece formed magnetic shield, and the side clamping plates and the end sealing plates in the single-piece formed magnetic shield are welded to a tank wall of an oiltank. The rolled welding type oil tank magnetic shielding structure is advantaged in that magnetic flux leakage distribution of a transformer body is improved, a noise level generated by magnetic shielding resonance is reduced, and firmness and reliability of magnetic shielding are improved.

Description

technical field [0001] The invention relates to an oil tank magnetic shield, in particular to a rolled and welded oil tank magnetic shield structure and a manufacturing method thereof. Background technique [0002] The magnetic circuit design in the body of the low-loss transformer with a voltage level of 110kV and above is the key to reducing the stray loss of the transformer, and the magnetic shielding of the fuel tank is a good magnetic flux leakage circuit. The traditional magnetic shielding structure of the fuel tank is a clip-on laminated type, such as Figure 1-7 As shown, one end of the magnetic shield 8 of the fuel tank is provided with a grounding piece 9, and each magnetic shielding 8 of the fuel tank needs to be fixedly connected to the ground seat 13 on the tank wall 1 through the grounding piece 9 to ensure that the magnetic shielding 8 of each fuel tank is evenly connected. Grounded, and the remaining parts are wrapped with cardboard 10 for insulation. After ...

AI Technical Summary

Problems solved by technology

Due to the resilience of the clip 12, the cardboard 10 between the clip 12 and the magnetic shield 8 of the fuel tank often falls off, easily causing the risk of multi-point grounding of the magnetic shield 8 of the fuel tank; at the same time, the clip 12 is welded on the wall 1 of the fuel tank and hammered. The latter is very easy to break, and the magnetic shield 8 of the fuel tank has a negative impact on its magnetic permeability after being hammered by an external force; in addition, the clip-mounted magnetic shield is not fixed firmly enough to easily generate hysteresis resonance, which is also the source of transformer noise

Therefore, the magnetic shielding structure of the existing card-mounted laminated fuel tank is cumbersome, with many processing procedures and many types of materials. The fixation is not firm, and it is easy to generate vibration, which is the source of noise; The included angle, the magnetic resistance is large, and the absorption of magnetic flux leakage is not sufficient and thorough, and some magnetic flux leakage still enters the steel plate of the tank wall without being closed by the magnetic shield to generate eddy current loss

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