Design process and simulations for the rotor system of a high-efficiency 22 kW micro-gas-turbine range extender for electric vehicles
Heesoo Kim, Charles Nutakor, Shruti Singh, Ahti Jaatinen‐Värri, Janne Nerg, Juha Pyrhönen, Jussi Sopanen
Abstract
This paper proposes a design process for a high-efficiency micro-gas-turbine (MGT)-based range extender(RE). The study includes a conceptual system design and a detailed design of an MGT RE. This design adopts a two-spool intercooled and recuperated high-speed MGT. The study focuses on the design of a low-pressure (LP) rotor system integrated with an electric generator, where a permanent magnet synchronous generator (PMSG) with a round transversally polarized bar permanent magnet (PM) is selected as a generator type. The turbine and compressor sides of the rotor are supported by dual back-to-back angular contact ball bearings modeled using a detailed five degrees of freedom contact model. The bearing cartridge is supported by squeeze film dampers (SFDs). The SFD that supports the bearings is modeled with a linear spring and an oil-film damper. Simulation results dictate that stresses in the magnet and sleeve vary due to several design parameters, thus time-efficient simulation is strongly required for effective design optimization. Also, the results indicate that the SFD design optimization range leading to acceptable rotordynamics requirements is narrow.