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In order to study the fluid flow characteristics and temperature distribution of high-speed permanent magnet synchronous motors, taking a 200kW, 20000r/min permanent magnet synchronous motor as the research object, a three-dimensional solution domain model is established based on computational fluid dynamics and heat transfer theory. The finite volume method is used to numerically analyze the temperature and fluid field of the motor. The results reveal the temperature distribution of the internal components in the motor, and confirm the strong coupling relationship between the fluid and temperature fields of the motor. The calculation results provide a reference for the optimization of the cooling system of high-speed permanent magnet synchronous motors.

Temperature rise is an essential factor affecting the safety operation of electric machines. An appropriate solving domain is the first step to consider when calculating the temperature rise. However, the effect of solving domain setting on the calculation results of electric machine temperature rise has not been deeply discussed. In this paper, a 3MW permanent magnet wind generator is taken as an example. Based on the electrical and numerical heat transfer theories, two different solving domain models are established to compare the flow thermal characteristics of the internal and external ventilated paths. The fluid velocity changes in external ventilated path, the central section temperature rise and the velocity trace distribution of the internal ventilated path are compared in detail. Furthermore, the temperature rise of each component is analyzed. It is found that the fluid development in the generator is affected by solving domain selection. The results can provide a reference for accurate calculation of temperature rise of permanent magnet wind generator.

For the sake of studying the electromagnetic properties of doubly-fed turbine generator. This paper proposed a method which adds an equivalent impedance to simulate the doubly-fed turbine generator’s rated state in Maxwell Circuit Editor. Time–stepping finite element was adopted to calculate. Transfer radial air-gap flux density as FFT, getting harmonic content and the influence of harmonic wave on loss. DOI: http://dx.doi.org/10.11591/telkomnika.v11i2.2006 Full Text: PDF

That fluid flow states inside large generator stator radial ventilation duct is one of important facts which to decide the effect of stator ventilation and cooling, there is important significance to investigate. In this paper, the fluid movement differential equations are presented according to the theory of fluid dynamics, then the fluid field solved regions of ventilation radial duct with circular flow object or not is established respectively, the fluid fields are calculated numerically using finite volume method based on giving the corresponding solve conditions. The fluid flow characteristics inside ventilation duct with circular object or not are compared, the differences of fluid flow characteristic for the two ventilation structures are indicated, and some useful conclusions were achieved by which the theory foundation is established for large generator stator heat transfer characteristic.

The asynchronous starting of salient synchronous motor is comparatively convenient and economical way. The distribution of the currents and the temperature of the damper bars in laminated core are of the important problems for estimating this method. In this paper, current mathematics model of salient synchronous motor is established on the basis of state equations at the time of starting, and a TZ99/51-6 salient synchronous motor is taken as an example, the damper bars current is calculated during starting. At the same time, physical model and mathematics model of rotor 3D transient temperature field are built, differential equations are variated and diverged by using of 8 nodes hexahedral unit and collectivity combination equation of 3D transient temperature field is educed. Finally, salient synchronous motor rotor temperature fields are computed in the process of starting, by comparing with the measured values to indicate the calculation method is fit for project practice and some useful conclusion are drawn.

In this paper the mathematical model of the rotor temperature field in a hydro-generator is established, and assumptions of the solved region in the hydro-generator are presented. The steady temperature field in the rotor is calculated by 3D finite element method, and the results are very well agreement with the measured values. The heat transfer theory is applied to study the influence of the uneven surface heat transfer coefficients on the temperature of rotor's windward side and leeward side in middle and end part of rotor. Also, the influence of the extra loss on the surface of pole on rotor temperature field is analyzed. Finally, some valuable conclusions are obtained