Equalizing Currents in the Armature of a D-C. Machine

This paper contains an analysis which shows how the equalizing currents in the armature coils of a d-c. machine act to correct the unbalance causing these currents to flow. It is shown that even with very small inequalities of main pole air gaps (plus or minus 7 per cent of an average main pole gap), the equalizing current in an armature coil may reach, several times each revolution of the armature, a peak value as high as 25 per cent of the full load coil current value. The analysis is unique in that it is based upon experimentally determined curves of equalizing current variation in an actual machine.