Application of Integrated Windings in Homopolar Inductor Motors

Abstract

The article considers the design of a homopolar inductor machine excited from an integrated winding that concurrently produces the rotating armature magnetic field and the excitation field. The use of an integrated winding makes it possible to simplify the machine design, to decrease the consumption of insulation and structural steel, which simultaneously serves as part of the externally closed magnetic core for the passage of excitation flux in the axial-radial direction. The integrated winding distribution among the coil phases for the multiphase version is detailed, and the integral MMF distribution curve for the three-phase four-pole version of the winding is plotted. More accurate dependences for calculating the electromagnet torque of a motor with tooth structures on the rotor and stator are proposed that take into account the change of the gap permeance when the rotor is shifted by half the slot pitch. The torque values are substituted in the Arnold constant equations for determining the bore diameter in designing. A formula for estimating the thermal state of the machine with an integrated winding is given. A conclusion about the possible application fields of homopolar inductor motors with the integrated winding has been drawn: for operation in repeated short-term modes, when there is a need to force the torque, and when used in combination with a permanent-magnet machine on a common shaft.