Improving the Efficiency of Electrical High-RPM Generators With Permanent Magnets and Tooth Winding

Abstract

Abstract-This paper solves the problem of minimizing losses in the stator magnetic core of high-speed electric machines with the use of amorphous iron. A fundamentally new technology for manufacturing of a stator magnetic core from segments of amorphous steel is developed by the authors. The feature of the new stator design is the possibility to use technological ducts located inside the stator as cooling ducts. This aspect significantly improves the heat dissipation from the active zone of the stator and, accordingly, minimizing temperature. The efficiency of this solution was studied using two power generators of 100 kW and 200 kW and rotational speeds of 60,000 rpm and 45,000 rpm respectively in the software complex Ansys Maxwell. Harmonic compositions of currents and voltages, flux density distributions in active elements of the generator in various operating modes were studied: under load, in a three-phase short-circuit and at idle. Also, the obtained data were compared with analogous models of an electrogenerator made of electrical steel. The results of the study showed the operability and effectiveness of the proposed technology. Based on the results of the research, a prototype of the stator magnetic core made from amorphous iron was created. Losses in the generator were experimentally measured. Also the results of experimental studies of aerodynamic losses are presented.

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Diagnostic Method of Rotor Cracks and Local Demagnetization by Using the Measuring Coils for the Permanent Magnet Synchronous Machines

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