Envisioning power system data: vulnerability and severity representations for static security assessment

This paper deals with graphical representations for power system static security assessment. Previous work has developed a graphical representation for a single power system state. This work develops graphical representations for a global display of power system security, using basic visualization principles previously established, that efficiently and effectively communicates the influence of the contingency set on the power system. Such representations are increasingly necessary because of the growing speed with which hardware can generate data. The problem is no longer computing the answers, the problem now is understanding them. Graphical visualization is a key part of the solution. In this paper, visualizations for security assessment are developed based on standard performance indices. These convey the following information: (1) how the loss of one element affects the rest of the system, i.e. the severity of the loss of each element, and (2) how each element of the power system is affected by the contingency set, i.e. the vulnerability of that element. These two different aspects of security require two different representations, and some simple user interactions to move between them. A key benefit of visualization is the display of severity or vulnerability results from the entire contingency set on one page in a geographic context