Identification of voltage collapse through direct equilibrium tracing

This paper describes an approach for identifying power system voltage collapse. Unlike the conventional two-step procedure, it simultaneously solves the system differential and algebraic equations (at steady state) to obtain the equilibrium points. Combined with a parameterized continuation technique, the methodology identifies voltage collapse during the direct equilibrium tracing, without rebuilding system dynamic Jacobian and checking its singularity. This significantly reduces the computational cost. All the assumptions of slack and PV buses are removed. The generator field and armature current limits are also accurately implemented. Numerical test results with the New England 39-bus system are presented. Three more systems with up to 8267 buses and 1112 machines are employed to demonstrate the capability of the approach.