Characterization of ferrite cores at high frequency : measurement and theoretical analysis

Abstract

In this thesis a new method is presented to measure the magnetic core losses. This method uses an impedance analyser and adopts the phase compensation approach to effectively reduce the impedance measurement errors introduced by phase-shift due to inherent parasitic impedance or time delays in the measurement system. In order to determine the influence of winding turns on the core loss measurement, the fields' distribution due to current-carrying winding in the toroidal cores with circular and rectangular cross sections is analyzed based on the space geometry and filamentary current. From the computed results, it is found that the area covered by the winding has much larger exciting magnetic field strength than those areas uncovered by the winding.