This article describes the purpose and applications of the starter generator set. The modes of operation of a starter-generator set are considered both as a sequential excitation direct current electric motor, which rotates the shaft of an internal combustion engine, and as a generator, when an electric machine operates as a direct current source of independent excitation, supplying power to electric control circuits, electric motors of auxiliary electrical equipment, lighting and battery charging. Additional functions of a starter-generator set in the form of a start-stop system, regenerative braking, booster acceleration of a vehicle, damping of torsional moments of the shaft of an internal combustion engine and control of energy flows in the on-board network were studied.
 The choice and substantiation of the optimal scheme, as well as the design of the starter-generator device, were carried out. The main technical and economic parameters of the starter-generator set were determined. The design of a starter-generator set was presented. This design is a reversible electric machine. A block diagram of a starter-generator set was developed.
 Electrical machines used for starter-generator sets are considered. The design of an asynchronous machine with a squirrel-cage rotor, a synchronous machine with electromagnetic excitation, a valve machine with permanent magnets, a contactless machine, a synchronous machine with permanent magnets, and a valve machine with self-excitation are described. A review and analysis of electrical machines used in starter-generator sets of leading foreign companies is carried out.
 The design of a reversible induction-dynamic machine is considered. The rotor rotates outside, and not inside the motor and is a short-circuited winding with a cast aluminum cage. The calculation of the main parameters of a reversible induction-dynamic machine was carried out both in the starting and in the generator modes. The calculation using a method similar to that of an induction motor was carried out.