How Permanent Magnets Bonding Methods Affect the Rotor Mechanical Strength in an SPM Synchronous Starter

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 the inductor of which has permanent magnets on the rotor-core outer surface. It also examines the mechanical strength of the rotor when starting the GTE for different permanent-magnet and core connection methods. The problem is solved in several ways. The paper presents an approximate analytical solution and finite-element modeling in two settings: an equivalent non-rotating rotor and a real rotating rotor. The obtained results are compared to each other and then validated experimentally. The paper draws the recommendations on which the magnet bonding methods should be selected depending on the rotor rotation speed, the operating temperature, and the residual stresses in the bandage fixtures.