The Relay Protection of High Voltage Networks presents the theoretical aspects of relay protection of high-voltage electrical networks. This book covers a variety of topics, including sequence networks for complex asymmetrical states, vector locus method, theories of symmetrical component filters, and power directional devices. Organized into 10 chapters, this book begins with an overview of the use of sequence networks. This text then examines the relay protection of high-voltage networks with three-phase and single-phase tripping. Other chapters consider the principles of auxiliary devices, which serve for the selection of the faulty phase and for preventing the incorrect operation of protective gear during swings and for faulty conditions in the secondary windings of voltage transformers. The final chapter deals with the stability of parallel working of power stations in a system. This book is a valuable resource for engineers, student, research workers, and readers specializing in the field of relay protection.