A 250-V dc series motor with compensating winding has a total armature circuit resistance of (R_{a} + R_{se}) = 0.08 \Omega. It is run at 1200 rpm by means of a primemover with armature circuit open and series field separately excited. This test yielded the following magnetisation data:
I_{se}(A) |
40 | 20 | 120 | 160 | 200 | 240 | 280 | 320 | 360 | 400 |
V_{OC} (V) | 62 | 130 | 180 | 222 | 250 | 270 | 280 | 288 | 290 |
292 |
Sketch the speed-torque characteristic of the series motor connected to 250 V main by calculating the speed and torque values at armature currents of 75, 100, 200, 300, 400 A.