Analysis of d.c. series motor controlled by power pulses

The main problem in the analysis of the chopper-fed d.c. series motor arises due to the nonlinear relation between the armature induced voltage and the armature current. Because of this, the differential euqations which describe the operation of the motor in different modes of a chopper cycle are nonlinear. Exact solution of these equations can only be obtained numerically by the use of considerable computation time. The paper describes certain approximations which permit the derivation of simple but accurate analytical methods for the analysis of the d.c. series motor fed by a chopper, with either pulse-width control or with current-limit control.