Commutation analysis of universal motors taking into account brush-to-bar voltage drop

Abstract

This paper presents a novel commutation analysis of universal motors taking into account the brush-to-bar voltage drop. Time-stepping finite element analysis has been used to compute the brush-to-bar voltage drop of the universal motors, where the measured curve of the brush voltage drop is used instead of that due to the brush-to-bar contact resistance. Computed results of the voltage between a brush and a leading bar at the trailing edge for a AC100V universal motor are obtained.