Research on the Effect of Clamping Force on Amorphous Alloy Magnetic Properties and Core Vibration

Amorphous alloy materials are known for energy saving. Amorphous power transformers have lower core losses than silicon steel transformers, but the magnetostriction coefficient of amorphous alloys is large, which will result in greater core vibration of the amorphous transformer during operation, and the noise level varies The increase. Electromagnetic vibration not only affects the service life of equipment, but also causes more and more attention to the noise environment. Therefore, how to design and manufacture amorphous power transformers with low vibration and noise has become an urgent problem to be solved in its promotion and application.

Scientists measured the magnetic properties of the amorphous strip and the amorphous wound core respectively, and obtained the magnetization and magnetostrictive properties of the core under different clamping forces. Based on the measurement data, the magnetic field and stress vibration of the amorphous iron core under different clamping forces are analyzed, and the vibration of the core under different clamping forces of the prototype is measured and analyzed. Finally, the influence of the clamping force on the vibration of the amorphous iron core is summarized and analyzed.

Researchers built an experimental platform for magnetic characteristics under clamping stress based on the structural characteristics of the amorphous distribution transformer core, and completed the measurement of the basic magnetization and magnetostrictive characteristics of the amorphous alloy coiled core under different clamping forces (Figure 1, figure 2). The magnetic field and stress vibration calculation and analysis of the amorphous coil transformer are realized, and the vibration conditions of the prototype core under the same working magnetic density and different clamping forces are measured. The acceleration and frequency spectrum changes are compared and analyzed, and the clamping force is obtained. The influence of the vibration of the amorphous alloy roll core is as follows:

Figure 1

Figure 2

(1) The local application of clamping force on the amorphous alloy wound core has little effect on its magnetization characteristics, and its permeability is slightly reduced only when the magnetic flux is high; but the clamping force has an impact on the magnetostrictive effect of the amorphous iron core Larger, showing a non-linear change (Figure 3).

Figure 3

(2) Through the comparison and analysis of the calculation and measurement of the amorphous iron core vibration under different clamping forces, the rationality of the numerical calculation results of the magnetic-mechanical coupling is verified. The comparison and analysis of calculation and experimental results show that the vibration of amorphous alloy changes significantly under the action of clamping force, and the vibration acceleration in the direction of force decreases with the increase of clamping force, but the vibration in the direction of magnetization has a nonlinear relationship with clamping force. Therefore, it can be concluded that adopting an appropriate clamping force can effectively suppress the vibration of the amorphous alloy rolled core during operation (Figure 4).

Figure 4

(3) The core vibration of the 500kVA amorphous alloy dry-type transformer is calculated and measured. The power equipment is analyzed based on the measurement results of the core magnetic characteristics of the small prototype. The results show the correctness of the model. The analysis under different stresses is the amorphous configuration. The vibration control of the electric transformer core provides an effective analysis and reference method. In the later stage, it will be further designed and implemented to apply a certain clamping force to the core of the amorphous distribution transformer and conduct experimental research on it. The research results of this paper provide a theoretical basis for the calculation and evaluation of the electromagnetic vibration of amorphous transformers, and provide an analysis method for the research on vibration and noise reduction of amorphous alloy iron core equipment under stress.

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