The book "Relay protection and automation in power supply systems" by A. M. Ershov is an indispensable guide for engineers, professionals and students seeking to better understand the complex and crucial aspect of modern energy infrastructure. In this work, the author masterfully combines theoretical foundations and practical solutions, revealing to the reader the full versatility and importance of relay protection and automation systems in ensuring the reliability and safety of electricity supply. In the pages of the book, Ershov immerses himself in the fascinating world of automatic systems that serve not only to protect equipment, but also to guarantee the stable operation of the entire energy system. He examines in detail the principles of operation of relay devices, their role in the prevention of emergency situations and automatic response to various malfunctions. The book is saturated with examples from real practice, which makes it a particularly valuable resource for practicing engineers working in power plants, grid companies and design bureaus. At the same time, it will be an excellent training tool for students of energy specialties who want to master modern methods of automation and protection of power grids. The book focuses on modern technologies and innovations in the field of relay protection, including digital relays, remote control systems and the integration of automatic systems with information technology. Ershov not only explains the technical details, but also shows how these systems help to improve efficiency, reduce the risks of accidents and ensure uninterrupted power supply in the face of growing demands for the reliability of the energy infrastructure. His style of presentation is clear and logical, which makes complex technical concepts available even to those who are just starting their way in the field of electricity supply. The book "Relay protection and automation in power supply systems" is not just a collection of technical rules, but a real guide to the creation and operation of modern protection systems. It raises important topics related to automation, cybersecurity and sustainability of energy systems, making it relevant in the face of global challenges and the need to transition to more intelligent and reliable networks. Ershov masterfully shows how modern technologies help to solve the most complex problems associated with the management of power grids, and why it is the correct design and configuration of protection systems that are the key to their trouble-free operation. This book will be of interest not only to specialists in the field of electricity supply, but also to those who are interested in innovations in energy, automation and control systems. It can be recommended to engineers, designers, students and graduate students, as well as managers of energy enterprises seeking to increase the level of reliability of their systems. Ershov, an author known for his deep knowledge and practical experience, created a work that combines scientific rigor and practical value, making it an indispensable tool for professional growth and development. If you are looking for a book that will help you understand how modern security and automation systems ensure the safety and efficiency of electricity supply, then “Relay protection and automation in power systems” is exactly what you need. This book is your reliable companion in the world of high technologies and complex engineering solutions, it will open up new horizons of knowledge and opportunities for professional improvement.