Heating the Starter with Magnetoelectric Excitation During Hot-Start and Dry Motoring of a Gas-Turbine Engine

The electric start of a gas-turbine engine (GTE) in gas transport systems is advantageous over turbo-expander start. Serially produced starts based on asynchronous motors with a squirrel-cage rotor are inferior to magnetoelectric excitation based on energy performance. This paper dwells upon designing a magnetoelectric-excitation starter whose inductor has permanent magnets either inside the rotor core or on the surface. We have designed, produced, and tested a number of 65- to 250-kW starters that are considerably more powerful than their counterparts in terms of power density. We herein examine machine heating during the hot start and dry motoring of a GTE. The unsteady problem of computing the starter temperature field is solved by the finite-element method in 2D and 3D formulations. The results are compared to the empirical data. We draft guidelines on choosing the insulation materials for the grooves and frontal parts of the stator winding.