Analysis of Transient Magnetic Flux in Interpole of DC Motor Considering Hysteresis Phenomenon

Abstract

We first formulate a numerical calculation to solve the two-dimensional theoretical equations for an analysis of the transient response of the interpole flux in the dc motor. In this numerical calculation, the nodal method for considering Ampere's circuital law in space, and the Crank-Nicolson method for the time derivative are used. Next, we analyse the transient response of the magnetic flux, the distributions of the magnetic flux, and also the induced eddy current in the magnetic circuit simulating the interpole magnetic circuit in a dc motor, the yoke of which is constructed with a solid iron core. As a result, it is made clear that the interpole flux is delayed to the abrupt change of an armature current by the eddy current induced in the yoke. It is also clear that a large magnetic flux concentrates in the inner skin region of the yoke, because of the eddy current and the magnetic hysteresis. Moreover, it is noted that the distribution of the magnetic flux in the yoke is influenced very much by the conductivity of the yoke and the magnetic hysteresis. Finally, we obtain a fairly good agreement between the calculated and the experimental results of the transient response of the magnetic flux.