Harmonic Analysis of Electromagnetic Casting System

It's a new processing method to apply magnetic field to the twin-roll aluminum casting area to improve the quality of clad strips. It needs a special alternated magnetic field in the casting area. Design and study the shape of the magnetic density in the casting area is very important to help understand the solidification-deformation process. This paper presents a twin-roll aluminum electromagnetic casting system with a 3-phase AC/AC converter which is controlled independently, and introduces its current control method. Through harmonic analysis and real-time measurement, it is found that the electromagnetic system has complex and rich harmonic wave, which is available to improve quality of the slab. The spectrum analysis shows that the basic frequency of each phase's current is half of the given central control frequency. Metallographic analysis of the 1070 aluminum cast by the AC/AC converter shows that applying AC/AC converted electromagnetic casting system instead of Al-Ti-B modificator can also obtain the same grain refinement effects, and impurity elements are distributed more uniform.