Comparison of output characteristics of a permanent-magnet and a field-winding DC starter motor

The influence of magnetic saturation on electromagnetic field distribution in both permanent-magnet direct-current (PMDC) and field-winding (wound-field) direct-current (FWDC) motors with the same output mechanical power, have been studied. In this paper, an approximate analytical method and finite element method (FEM) are used for prediction of airgap flux density distribution. No-load and rotor-locked conditions, according to experimental measurements, and the FEM and analytical method studies of the motor, have been studied. A sensitivity analysis has also been done on the major design parameters that affect motor performance. At last, these two DC motors are compared, in spite of their differences, on the basis of measured output characteristics.