This text provides practising engineers with a reference and tutorial on power system protection. Each chapter describes the various devices and schemes used in the protection of electrical power systems. Schemes currently being produced are examined at length. In each case, the behaviour of the items of plant to be protected and the faults which may occur are thoroughly explored. Numerous examples are drawn from current international practice to illustrate the points being made. A brief history of early electronic power system devices is also included, written in a clear and concise manner, without recourse to lengthy mathematical treatments. The limitations of early equipment are outlined and the subsequent developments or features needed to make them suitable for present-day systems are presented. This book should be a reference tool for engineers involved in power system protection. This book is designed for engineers, researchers and graduate students in electrical engineering.