This textbook is designed for engineering students specializing in mechanical engineering. It explores the properties of regulated objects in thermal power installations, including sensitive, amplifying, and stabilizing elements, as well as automatic control systems (ACS) of both direct and indirect action. The book provides an analysis of the stability of ACS operations using stability criteria and I.A. Vyshnegradsky's diagrams, along with the fundamental methods for assessing the quality and synthesis of control systems. The second edition includes new material on the application of digital computers in calculating the stability and quality of ACS, along with relevant calculation programs.