An Analysis of Solid Rotor Machines Part II. The Effects of Curvature

In Part I of this series on the impedances of polyphase rotating machines with a solid rotor, the operational impedances and direct-and quadrature-axis equivalent circuits were developed from electromagnetic field theory. The previous work has neglected the effects of curvature. It is shown in this paper that for most machines of conventional dimensions, the effects of curvature are relatively minor. This paper presents the results of an analysis of an electromagnetic model which includes curvature. Equations for operational and equivalent circuit impedances are presented and numerical data for both 2-and 4-pole machines are given for operating conditions in which the rotor-iron currents are sinusoidal.