This paper examines the possibility of using photoelectric energy conversion during creation of electric unmanned aerial vehicles of a hybrid type. These vehicles should operate at altitudes up to 22,000 m and have an unregulated flight time. The problems arising during creation of such devices are their instability and poor controllability. Also they possess a number of disadvantages typical for airships: large size and, as a consequence, high windage and dependence on weather conditions; low maneuverability and, as a consequence, the difficulty of landing. These negative aspects of all circular wings resulted in complete rejection of their development. However, the considered disadvantages show the feasibility of creating hybrid aircraft. Particular attention in this paper is given to disk-shaped vehicles. They have less windage, do not need to turn around when changing the direction of flight. The presence of solar panels in combination with modern control and navigation systems make it possible to create new unmanned aerial vehicles with unlimited flight time. The aircraft dimensions are calculated as a function of the lifted mass and other parameters. Recommendations on possible operation parameters of hybrid airship are given.

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Writing the differential equations of an asynchronous electric motor on the basis of a generalized electric machine in different coordinate axes can not only reduce the number of model equations, but also introduce various factors in the mathematical description that increase the modeling accuracy. It is proposed to write the equations of the mathematical model of an induction motor taking into account the saturation of the magnetic circuit and solve them using the Matlab application package. The proposed approach improves the accuracy of calculating the mechanical characteristics of an asynchronous electric drive.

The textbook describes the main issues of the theory of relay protection and automation of electric power systems. The structure and functional purpose of protection devices and automation of power transmission lines of various configurations, synchronous generators, power transformers, electric motors and individual electrical installations are considered. For each of the types of protection of the above objects, the structure, the principle of operation, the order of selection of settings are given, the advantages and disadvantages are evaluated, indicating the scope of application. The manual includes material on complete devices based on semiconductor and microprocessor element bases. The progressive use of such devices (protection of the third and fourth generations) is appropriate and effective due to their significant advantages. Meets the requirements of the federal state educational standards of higher education of the latest generation. It is intended for students in the areas of training 13.03.02 "Electric power and electrical engineering" (profile "Power supply", discipline "Relay protection and automation of electric power systems") and 35.03.06 "Agroengineering" (profile "Power supply and electrical equipment of agricultural enterprises", discipline "Relay protection of electrical equipment of agricultural objects"), as well as for graduate students and specialists engaged in the field of electrification and automation of industrial and agrotechnical objects.

The article discusses promising designs of high-speed electric motors for autonomous medical instruments. These machines ensure the creation of an autonomous electromechanical tool with low energy consumption, which predetermines the possibility of its use in field conditions. On the other hand, higher ergonomic indicators contribute to better performance of operations.