Propagation of magnetization wave in a magnetic core due to localized magnetizing field and its potential application to determining the locations of winding partial discharge

This paper studies propagation phenomena in a magnetic core due to localised magnetizing source. Analytical solution for the distribution of the magnetic field in a toroidal core produced by current-carrying conductors is derived and numerical results are obtained, which demonstrate that the localized magnetizing source incur non-uniform magnetizing field in different parts of the core. Experiments are introduced to verify the existence of magnetization delay due to the localised magnetizing field. A qualitative explanation for the delay is given based on the derived propagation constant in magnetic materials. The feasibility of using this delay phenomenon to identify the locations of partial discharge is discussed.