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.