Generalised analysis for steady-state characteristics of DC commutatorless motors

Much work has been done on the analysis of the characteristics of DC commutatorless motor drives based on synchronous machines. These studies have not resulted in a clear picture of the collective effects of damper windings, compensating windings and saliency on machine performance. The development of a generalised analysis in terms of machine inductances and other basic parameters by which the effects can be examined collectively is described. The variation of commutation angle, shift angle and demagnetisation due to armature reaction, safety-margin angle, average torque and speed with mean input current are examined quantitatively for machines with d-, q-damper and compensating windings and saliency. Some experimental results are included.