Identifying generator outage from line flows

Contingency analysis is a common yet important study in power systems. It provides answers to `What if.?' questions and is used for preventive control. In this paper we pose an inverse problem, not discussed earlier in power system literature - Given the change in power flow on a line, is it possible to find out which of the generators has stopped injecting power to the system network? This poser becomes difficult to answer since identity of individual generators in line flows is lost the moment its power gets distributed on multiple lines connected to its system node. To the best of our knowledge no method exists that can identify generator outage from line flows. We employ in this paper a new, and recently reported, concept of Kirchhoff State and propose a diagnostic procedure that will identify an outaged generator from line flows. Only the usual system data and, flow measurements on a line, before and after the outage, are required. No iterative techniques are used. Illustrative examples are given.