Book excerpt: This book examines the problems of power systems in fields related to optimization of operating modes of electric power facilities and their control systems, information and measuring systems and metrological support in the electric power industry, ensuring the functioning of the electric power system in the conditions of a competitive market of the electric power. The book is devoted to modern problems ensuring operational reliability and safety of objects integrated power system of Ukraine. It is complex task, solution of which is related to optimization of operating modes of electric power facilities and their control systems, creating diagnostic systems for the electric power industry, ensuring the functioning of the electric power system in the conditions of a competitive market of the electric power. The presented research results in book allow increasing the reliability and efficiency of operation of energy facilities and ensuring the stability of power systems, the introduction of effective methods and tools for forecasting electricity supply, optimize power systems, suggest road map to integrate electricity markets taking into account network constraints in modern conditions of electricity markets. The book includes eight chapters. A book is for researchers, engineers, as well as lecturers and postgraduates of higher education institutions dealing with problems of operation, control, diagnosis and monitoring of integrated power system, power equipment and other.