Regulation of A-C generators with suddenly applied loads

DETERMINATION of the voltage drop at the terminals of small generators during the starting of relatively large motors has long been an important problem, particularly in connection with the starting of large motors on power-house auxiliary generators. Interest in this problem has been greatly accentuated by the wartime application of many small a-c generators, in fixed and mobile locations, supplying motors of ratings amounting to an appreciable fraction of the generator rating. It is essential in such applications to be able to predict accurately the maximum voltage drop in order to be sure that motor starters on the line will not drop out and that motors already running will not stall when large additional loads are started. Other types of apparatus are critical to low voltages of short duration, particularly if such low voltages recur frequently.