Voltage stability is a major concern in the planning and operation of electric power systems. This is the first book to provide a clear, in-depth explanation of voltage stability, covering both transient and longer-term phenomena and presenting proven solution to instability problems. An essential tool for all electric power and utility engineers, the book describes equipment characteristics for transmission, generation, and distribution/load subsystems of a power system, together with methods for the modeling of equipment. Readers will find static and dynamic computer simulation examples for both small equivalent power systems and for a very large power system, plus an account of voltage stability associated with HVDC links. They will also get helpful planning and operating guidelines, computer methods for power flow and dynamic simulation, and descriptions of actual voltage instability incidents.