Magnetic Field Analysis of Magnetic Switch Subjected to Short Pulse

There is a disagreement between the experimental result and the calculated one according to the voltage-second formula for the magnetic switch subjected to short pulse. In order to make clear the reason of disagreement,Fourier transform is exploited to analyze the voltage waveform of magnetic switch,and spectrum of voltage is obtained,and then the magnetic field of magnetic core is calculated by finite element method(FEM) according to the spectrum. A design procedure for a practical magnetic switch is carried out. The entity model of magnetic core and winding is set up in the FEM analysis software ANSYS,and the material attribute such as relative magnetic permeability is assigned. Magnetic filed along a radial of magnetic core including static item and all harmonic ones is calculated. The voltage-second of magnetic switch is 9.98×10-3 V·s calculated in terms of magnetic flux density across ferrous lamina multiplied by lamina cross-sectional area. However,According to the formula,voltage-second is 12.6×10-3 V·s,so the utilization efficiency of magnetic core is 79.21%. At the same time,the distribution of calculated magnetic field along the radial mainly focuses on the surface of magnetic core,which leads to the decrease of utilization efficiency of magnetic core and is the main cause of the disagreement.