The reliable and secure operation of modern power systems depends fundamentally on effective protection schemes and advanced switchgear technologies. As electrical networks continue to expand in size, complexity, and voltage levels—while integrating renewable energy sources and smart grid technologies—the need for fast, selective, and reliable fault detection and isolation has become increasingly critical. Switchgear and protection systems form the backbone of power system safety, ensuring continuity of supply, protection of equipment, and prevention of catastrophic failures.

Switchgear and Protection is a comprehensive multi-author volume that brings together the expertise of academicians, researchers, and practicing engineers specializing in power system protection, high-voltage engineering, and substation automation. This collaborative effort aims to provide an in-depth and contemporary understanding of protective relaying principles, fault analysis, circuit interruption technologies, and emerging intelligent protection systems.

The book systematically presents the fundamental concepts of power system faults, protection philosophy, and relay coordination before progressing to advanced topics and practical applications. It covers:

• Types and characteristics of power system faults
• Protective relays: electromagnetic, static, and numerical relays
• Overcurrent, differential, distance, and directional protection schemes
• Generator, transformer, busbar, and transmission line protection
• Circuit breakers: oil, air-blast, SF₆, vacuum, and modern hybrid technologies
• Substation switchgear and insulation coordination
• Relay coordination and protection grading
• Digital substations and IEC 61850 standards
• Microprocessor-based relays and adaptive protection techniques
• Protection challenges in renewable-integrated and smart grid systems

Special emphasis has been placed on practical design considerations, coordination studies, and real-world case analyses to bridge the gap between theoretical understanding and field implementation. Numerical examples, relay setting calculations, and modern simulation approaches have been incorporated to enhance learning and application skills.

As a multi-author compilation, this book reflects diverse technical perspectives while maintaining academic consistency and clarity. Each chapter has been carefully reviewed and structured to ensure logical flow, technical accuracy, and contemporary relevance. The collective expertise of the contributors strengthens the book’s value as both a textbook and a professional reference.

This volume is intended for undergraduate and postgraduate students of electrical engineering, research scholars, faculty members, and practicing engineers working in utilities, substations, and power generation sectors. It may also serve as a reference guide for competitive examinations and professional certification programs in power systems.

The editors sincerely acknowledge the scholarly dedication of all contributing authors whose knowledge and research insights have shaped this work. We also extend our gratitude to reviewers, institutional authorities, and the publishing team for their invaluable support throughout the development of this book.

We hope that Switchgear and Protection will contribute significantly to the advancement of safe, reliable, and intelligent power system operation in the evolving energy landscape.