Evaluation of Energy Saving on the Axial Maglev Motor for Pediatric Ventricular Assist Device

Abstract

　A compact axial-gap type maglev motor has been developed for use in pediatric ventricular assist devices (VADs). The developed maglev motor consists of a top stator, a bottom stator and an impeller which is magnetically levitated with 5-degrees of freedom posture control. The motor is 22 mm in outer diameter and 33.6 mm in total height. In this study, design change of stator windings and material change of stator core were investigated to improve motor energy efficiency due to reduction of electrical losses. Energy consumption of the improved maglev motor and magnetic suspension performance were evaluated. Increase in turn numbers of smaller diameter windings reduced the copper loss of the drive line cable due to reduction of required excitation current. Magnetic powder core material effectively reduced the eddy current loss. The energy consumption of the improved motor sufficiently decreased at design operating speed of the maglev pediatric VAD without deterioration of the magnetic suspension performance.