Armature Control Method:

The main requirement of this Armature Control Method scheme is a variable voltage supply to the armature whose current rating must be somewhat larger than that of the motor. It is superior to the field control scheme in three respects, outlined below:

1. It provides a constant-torque drive. In the shunt motor case by keeping the field current at maximum value full motor torque can be obtained at full-load armature current at all speeds.

2. Since the main field ampere-turns are maintained at a large value, flux den­sity distortion caused by armature reaction is limited.

Unlike field control scheme, speed reversal can be easily implemented here.

There are three main types of armature control methods, namely,

  1. Rheostatic Control
  2. Shunted Armature Control
  3. Series-Parallel Control