Transients in Ultra-High-Speed Generators of Micro-Sized Gas Turbines
The article presents a research of the effect of different types of short circuits (SC) on the performance of the gas turbine and ultra-high-speed microgenerator (MG) in a wide frequency range (from 200 000 rpm to 1,000,000 rpm) at a power from 10 W to 1 kW. The studies are carried out on a specific two-pole 100 W, 500,000 rpm microgenerator with permanent magnets with a toroidal winding. The research is carried out by finite element method using Ansys Maxwell software. Numerical study by the finite element method is performed at the rated operation mode and various types of short circuits: single-phase, two-phase, three-phase circuits coil inside MG. By the results of these studies, we estimate a negative impact of different types of faults on the parameters of MG and the mechanical characteristics of the gas turbine. Also we consider various options MG with SC for various types of bearings. Then, using the full-sized 100 W sample we carried out experimental studies of the MG operation in nominal operation mode at the 500,000 rpm. That allows to verify the developed computer model and confirm the results of our practice research. The obtained results can be used in the aerospace industry for design the high reliability complexes such as new energy systems for satellite power supply, unmanned aerial vehicles and microturbines. In addition, it can be used to design the ultra-high-voltage electric machines with a high fault tolerance for the compressor plants, air supply systems of hydrogen fuel cells, new medical tools and machine tools.