The Under-frequency Load Shedding (UFLS) scheme has been used by utility companies around the world to mitigate frequency drop caused by simultaneous or cascading tripping of transmission lines and/or generators in a power system. In the effort to devise an optimal load shedding scheme, it is imperative that investigations are done on the many factors that may affect the response of the scheme ...

The stability index is a function of real & reactive power injected at that node as well as of node voltage. The report presents stability analysis of radial distribution networks. Two voltage stability indexes are used for identifying the node, which is most sensitive to voltage collapse. Therefore to calculate node voltages for varying operating conditions a simple load flow technique for sol...

Osteonecrotic collapse of the femoral head is a common refractory disease in orthopedics, and the occurrence of collapse is an important factor in the prognosis of this condition. Osteonecrotic collapse of the femoral head can be delayed or prevented by the formation of a sclerotic rim. This study used finite element analysis to evaluate the mechanical role of a proximal sclerotic rim on stress...

The increase in Distributed Generation (DG) penetration in distribution network can be used as a means of addressing the increasing load demand without the upgrade of transmission lines. However, this increasing demand despite the supplementary supply from DG sources can cause the system to operate at its maximum capacity or at point of voltage collapse. It therefore, becomes necessary to deter...

The collapse resulted in the media’s search for immediate answers to the following two questions; why did the bridge collapse and who is to blame? Speculative answers to the first question were proposed by the “Average Joe” and structural engineering experts alike, and involved the usual suspects; the growth from microscopic to catastrophic lengths of undetected cyclic load-induced fatigue crac...

At present, the evaluation of voltage stability assessment experiences sizeable anxiety in the safe operation of power systems. This is due to the complications of a strain power system. With the snowballing of power demand by the consumers and also the restricted amount of power sources, therefore, the system has to perform at its maximum proficiency. Consequently, the noteworthy to discover t...

The analysis of the bearing capacity of structures with a rigid-plastic behaviour can be achieved resorting to computational limit analysis. Recent techniques [3],[4] have allowed scientists and engineers to determine upper and lower bounds of the load factor under which the structure will collapse. Despite the attractiveness of these results, their application to practical examples is still ha...

Although several studies have investigated the effect of degradation on the behavior of structures, investigations on collapse margin ratios are rare in the literature. In this study, the effect of strength and stiffness degradation on collapse capacity of steel moment frames is investigated. The aim is to determine margin of safety against collapse using a probabilistic approach. For this reas...

The answer may be yes. A discrete model of energy-conserved wavefunction collapse is proposed. It is shown that the model is consistent with existing experiments and our macroscopic experience.

A voltage collapse event is complex and localized in nature, but its effect is extensive. A vital effect of voltage collapse is total system collapse or blackouts, which will result in a significant loss to utility companies. Online monitoring of power system stability has thus become an important factor for electric power utilities. The final resort prevent the occurrence of a voltage collapse...