Structure Design and Magnetic-Vibration Characteristics Analysis of Amorphous Alloy and Oriented Silicon Steel Composite Iron Core

Amorphous alloy and oriented silicon steel are common soft magnetic materials used in manufacturing distribution transformer iron cores. Amorphous alloy with the advantage of low loss density faces challenges like low saturation flux density and large magnetostriction. Oriented silicon steel has the advantages of high saturation flux density and small magnetostriction, but its loss density is high. The opposite magnetization characteristics of the sematerials make the distribution transformer iron core difficult to simultaneously achieve low loss and low vibration. The combination of amorphous alloy and oriented silicon steel can synthesize the advantages of both materials. Specifically, the composite iron core can take advantage of the high saturation flux density of oriented silicon steel to prevent the supersaturation of amorphous alloy. The core loss is reduced by the low loss density of amorphous alloy, and the vibration of iron cores is reduced by the small magnetostriction of oriented silicon steel. Therefore, it is essential to design the structural parameters of the composite iron core and rationally allocate the proportion of amorphous alloy and oriented silicon steel to reduce the core loss and vibration indistribution transformer iron cores. In the composite iron core, the amorphous alloy part adopts a planar wound iron core structure, and the oriented silicon steel part adopts aplanar stack iron core structure. The exciting coil bypasses both iron cores to realize simultaneous excitation. According to the structure of the composite iron core and the magnetization saturation characteristics of amorphous alloy and oriented silicon steel, an equivalent dual nonlinear magnetic circuit model is established, and the iterative calculation method of flux density distribution is proposed. On this basis, the free parameter scanning method is used to design the structural parameters of the composite iron core. Firstly, the value range of free parameters is set. Secondly, all candidate-free parameter sets are determined by arrangement and combination. Each group of free parameters represents a composite iron core structure scheme. Finally, the flux density distribution of the composite iron core in each scheme is iteratively calculated. Based on the constraint that the flux density of the oriented silicon steel iron core is higher than that of the amorphous alloy iron core, feasible structural design scheme sets are determined. A composite iron core is designed, and an experimental prototype is manufactured according to the design results. The calculated and measured results of the flux density distribution of the composite iron core are compared. The mean relative error of the flux density for the composite iron core is 1.747%, for the amorphous alloy iron core is 3.129%, and for the oriented silicon steel iron core is 7.663%, which verifies the proposed method. The no-load loss of the pure amorphous alloy core is 29.064 W, the pure silicon steel core is 109.810 W, and the composite core is 35.327 W. Compared with the pure oriented silicon steel iron core, the no-load loss of the composite iron core is reduced by 67.829%. The vibration displacement of the pure-amorphous alloy iron core is the largest, with a peak value of 1.085 μm. The composite iron core is the second, with a peak value of0.785 μm. The pure oriented silicon steel iron core is the smallest, with a peak value of0.019 μm. Compared with the pure amorphous alloy iron core, the vibration displacement peak of the composite iron core is reduced by 38.200%. © 2024 China Machine Press. All rights reserved.