Rectifier circuit for measurement of small power-angle oscillations

KNOWLEDGE of transient oscillations of synchronous machines is of considerable importance because of the application of such information to studies on system load changes which may lead to loss of synchronism, to voltage fluctuations, or to hunting. Although in many instances very large angular swings must be taken into account, for many investigations only relatively small angular swings are considered. In this latter class are problems of determining the effects of saturation on load angle, angular variations with attendant current pulsations for variable torque loads, and the prediction of stability under large load changes as determined from studies of loads causing small displacements.