Transient Distribution of Magnetic Flux in DC Motor

Abstract

We introduce a numerical calculation considering the nonlinearity of the permeability of iron cores for a transient response of the magnetic flux to an abrupt change of the armature current at the speed control of the dc motor. From the calculated and measured results of the transient response, it is made clear that the transient response is greatly influenced by the conductivity of the yoke. Also, from many calculated results of the time behavior of the flux distribution, it is seen that the flux concentration near the inner surface of the yoke is caused by the eddy current in the yoke, and that the armature slots have a fairly large influence on the flux distribution on the armature surface.