Using tangent vectors and eigenvectors in power system voltage collapse analysis

Nowadays, most electrical systems have been working more stressed which tends to lead to voltage stability problems. The understanding of the event which may cause the voltage collapse phenomenon has resulted in the development of a great number of simulation programs. Many tools have been chosen to help the determination of the weakest bus, with less computational effort as possible, in order to enable a quick response regarding the correction of the voltage level of the system as a whole. Eigenvectors and tangent vectors are a useful source of information of the system behaviour This two elements combined allow us to determine the critical bus and enable us with further analysis to determine the power sources that most influence the system voltage level. This analysis will allow operators to make decisions on what variables to work on in order to avoid the voltage collapse