A New Approach for Monitoring Voltage Security of the General Large Power System

A two level cellular structure in both the parameter space and the state space is identified. This allows a new approach for the security monitoring of the large power system from a different perspective through the concept of a feasibility region. The boundary of the feasibility region is composed of surface sections (defined by algebraic equations) of only three types. So the boundary and its distance from the operating point can be computed to directly measure the security of the operating point. A rudimentary power system is used to introduce and explain the new concepts.