For years, power system dispatchers, power plant and sub-station operators, and electrical power engineers and technicians have consulted this basic reference in electric power system operation. Now it's expanded to explain new approaches and address new problems facing power system personnel. How power stations operate, power system protection and stability, the economics of power system operation, and normal land emergency procedures are covered in detail. For quick reference or review, chapter summaries highlight the key principles and methods. Reflecting an increased use of communications in power system operations, the book outlines different methods of communication and their capabilities and limitations. This edition also includes important new material on impedance of parallel circuits and the effects of resistance on impedance.