No abstract

No abstract

In order to solve the problems of severe heating and cooling difficulty in the stator of air-cooled turbo-generator, a novel stator teeth internal ventilation structure with axial vents in the generator stator teeth is proposed. Based on this structure, global two-dimensional electromagnetic field models of 150MW aircooled turbo-generator with different stator teeth internal ventilation structures are established to study the influence of the axial vents of the internal ventilation structure on air gap magnetic flux density of the generator, magnetic flux density of stator teeth, stator core loss, and synchronous reactance. Furtherly, flow network models of the ventilation system with the different internal ventilation structures and fluid-heat transfer numerical models of stator with half axial and one tooth pitch of generator are established to calculate the effects of the structure on the temperature of stator winding, insulation and teeth. It can provide a new research idea for the ventilation structure of large air-cooled generator. INDEX TERMS Air-cooled turbo-generator, ventilation structure, electromagnetic field, temperature field

In the power transmission system, the semiconductor device in the inverter is one of the main fault points. When the open-or short-circuit fault occurs in the semiconductor device, the motor can be turned into the operation with open-phase fault. To take into account the non-ideal factors existing in the calculation, this study establishes a systemlevel calculation model including the permanent magnet synchronous motor (PMSM), inverter, and different control strategies, which is used to analyse the operating performance of the PMSM with or without fault-tolerant control under single-phase opencircuit fault. In addition, based on the finite element method, the current fault characteristic and the change of the internal magnetic field distribution before and after the fault are studied, and the temperature rise of the PMSM with and without fault-tolerant control is compared. The aim of this study is to compare the operating performance of the threephase PMSM under two common fault conditions, and quantitatively give the variation range of magnetic flux density and temperature rise. The theoretical analysis in this study is verified by building a systematic experiment platform. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.