Vibration Analysis of a Reactor Driven by an Inverter Power Supply Considering Electromagnetism and Magnetostriction

To design a new model to reduce the noise of a reactor under inverter power supply, the cause of noise should be investigated. We carry out vibration analysis of a single phase of a reactor while considering electromagnetism and magnetostriction to clarify the mechanism of noise generation in the reactor. In this analysis, magnetostriction is modeled three-dimensionally with equivalent nodal forces. First, the nodal forces in the cores of reactor due to the electromagetism and magnetostriction are calculated using the flux distribution obtained from magnetic field analysis. To determine the dominant cause of noise, the spatial distributions of displacements generated by both nodal forces are then obtained by static structure analysis and they are compared in detail. Moreover, the actual movements of the cores are calculated by vibration analysis. Finally, the effect of the hardness of the cores on noise generation is calculated and measured. It is shown that the hardness of the insulator inserted in gaps between cores affects the vibration and it seems to have an optimal value. Moreover, the analyzed results are proved by measurement.