Analysis of Electromagnetic Processes of the Voltage Control Unit of the Excitation Winding of a Three-stage Starter Generator

This paper considers the excitation system of a three-stage synchronous generator for aircraft applications in two modes of operation. The level of voltage generated by the subexciter is higher than required for excitation of the exciter, for regulation it is reasonable to use a system based on series connection of semiconductor rectifier and a step-down converter. A distinctive feature of the presented system is the possibility to use the three-stage synchronous generator not only as a generator of electric energy for the onboard power supply network, but also as an electric starter for gas turbine engines of an aircraft. The article presents the calculation of the starter and generator operating modes of the excitation system. The basic relations for the semiconductor converter circuit are obtained, the analytical expressions are confirmed by simulation modeling in the PSIM software package. The results of mathematical modeling formed the basis for the design of an experimental sample of a power unit in a hybrid integrated design, for a voltage regulation system of a three-stage synchronous generator.