This book is on applied superconductivity, which is one of the topical issues of modern science and technology. At present, the prospects for the practical application of superconductivity are obvious from both economic and practical points of view. It can reduce heat losses and reduce the weight and size of equipment; improve the reliability of electrical devices and power systems; create new devices. As a result, the achievements of applied superconductivity make it possible to perform effective retrofitting of equipment for scientific research, in medicine, electric power, electrical engineering, transport, and to introduce new advanced technologies that provide higher efficiency, significantly reducing working costs.