Abstract. Currently, timely comprehensive diagnostics and analysis is the most important condition for the reliable operation of power autotransformers. Continuous monitoring of power autotransformers during the entire service life allows you to detect possible damage after a short-circuit (emergency) situation, because during a short-circuit, the relay protection does not immediately turn off the autotransformer, and shock currents flow through it. windings that subject the elements of the autotransformer to mechanical overloads, as a result of which displacement and deformation of the core and winding of the autotransformer can occur. Two modes are considered in this article: normal mode and abnormal (emergency) modes of the power autotransformer at the "Yuksak" substation located in Yakkasaray district, Tashkent city, Uzbekistan. Diagrams of voltage and current changes on three phases of the line and three phases of the autotransformer, as well as information on activated protections and their response time were obtained. Diagrams were obtained using Ekra microprocessor panels.