Dynamic System Stability Part I - Investigation of the Effect of Different Loading and Excitation Systems

Analysis of the phenomena of stability of synchronous machines under small perturbations as examined by Demello and Concordial, has been extended to the following: First, the change of the parameters K1 to K6 of the block diagram describing the system (Fig. 1) has been investigated for different loading and power factors. From this a set of curves has been plotted. Such curves can be used to reach a general conclusion about the variations of such parameters by changing the operating condition, which is an important factor in dynamic stability studies. Second, the dynamic stability of the system, as affected by different excitation, has been analyzed. The systems investigated are thyristor-type and type-I excitation systems. Their effect on dynamic stability has been compared. The results obtained by mathematical analysis have been checked by both digital and analog computer. From this and analysis a set of rules was developed which helps in understanding the stability requirements.