scholarly journals Research on Electromagnetic Field, Eddy Current Loss and Heat Transfer in the End Region of Synchronous Condenser with Different End Structures and Material Properties

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4636
Author(s):  
Xiaoshuai Bi ◽  
Likun Wang ◽  
Fabrizio Marignetti ◽  
Minghao Zhou

Aiming at the problem of end structure heating caused by the excessive eddy current loss of large synchronous condensers used in ultra-high voltage (UHV) power transmission, combined with the actual operation characteristics of the synchronous condenser, a three-dimensional transient electromagnetic field physical model is established, and three schemes for adjusting the end structure of the condenser under rated condition are researched. The original structure has a copper shield and a steel clamping plate. Scheme 1 has no copper shield but has a steel clamping plate. Scheme 2 has no copper shield but has an aluminum clamping plate. By constructing a three-dimensional fluid–solid coupling heat transfer model in the end of the synchronous condenser, and giving the basic assumptions and boundary conditions, the eddy current loss of the structure calculated by the three schemes is applied to the end region of the synchronous condenser as the heat source, and the velocity distribution of the cooling medium and the temperature distribution of each structure under the three different schemes are obtained. In order to verify the rationality of the numerical analysis model and the effectiveness of the calculation method, the temperature of the inner edge of the copper shield in the end of the synchronous condenser is measured, and the temperature calculation results are consistent with the temperature measurement results, which provides a theoretical basis for the electromagnetic design, structural optimization, ventilation and cooling of the synchronous condenser.

Actuators ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 78
Author(s):  
Tomislav Strinić ◽  
Bianca Wex ◽  
Gerald Jungmayr ◽  
Thomas Stallinger ◽  
Jörg Frevert ◽  
...  

A sealless pump, also known as a wet rotor pump or a canned pump, requires a stationary sleeve in the air gap to protect the stator from a medium that flows around the rotor and the pump impeller. Since the sleeve is typically made from a non-magnetic electrically conductive material, the time-varying magnetic flux density in the air gap creates an eddy current loss in the sleeve. Precise assessment of this loss is crucial for the design of the pump. This paper presents a method for calculating the eddy current loss in such sleeves by using only a two-dimensional (2D) finite element method (FEM) solver. The basic idea is to use the similar structure of Ampère’s circuital law and Faraday’s law of induction to solve eddy current problems with a magnetostatic solver. The theoretical background behind the proposed method is explained and applied to the sleeve of a sealless pump. Finally, the results obtained by a 2D FEM approach are verified by three-dimensional FEM transient simulations.


2011 ◽  
Vol 304 ◽  
pp. 41-47 ◽  
Author(s):  
Zhi Gang Zhao ◽  
Fu Gui Liu ◽  
You Hua Wang ◽  
Peng Xiang Ren ◽  
Yu Huai Kan

With the advent of power electronic technology, the excitation conditions applied to transformers, motors, etc. could be very atypical. DC bias excitation is an undesired working condition of AC power transformers, the asymmetrical saturation of the transformer core, the heavy noise, the serious vibration, and the local loss concentration can all potentially occurred in dc-biased transformers. The effect of the exciting current under different dc-biased magnetization on eddy-current loss in copper plate based on a reduced engineering-oriented benchmark model (TEAM Problem 21) is investigated. Experiment scheme for dc biasing is presented and the distribution of the eddy current loss under different dc-biased excitation conditions was studied in detail. The engineering applicability of three dimensional eddy current analysis methods for dc-biased magnetization field computation and the practical loss modeling are examined, which has been demonstrated via the numerical modeling results and the measured data.


2013 ◽  
Vol 49 (2) ◽  
pp. 939-945 ◽  
Author(s):  
Likun Wang ◽  
Feiyang Huo ◽  
Weili Li ◽  
Yihuang Zhang ◽  
Qing Li ◽  
...  

2010 ◽  
Vol 670 ◽  
pp. 466-476 ◽  
Author(s):  
Jian Li ◽  
Jung Tae Song ◽  
Yun Hyun Cho

This paper describes thermal analysis of canned induction motor for coolant pump considering eddy current loss. The electromagnetic field of a canned motor was analyzed by using the time-step finite element method, and the eddy loss was obtained. Equivalent circuit considering can loss was developed and the equitation to calculate can loss was derived from theory of conventional motor. Using the loss from electromagnetic analysis as heat source of temperature field, thermal analysis was conducted by three dimensional finite element analyses. The simulation results show good agreement with experiment data, which indicates that this method has good accuracy and reliability for dealing with thermal behavior of canned motor.


2021 ◽  
Vol 2093 (1) ◽  
pp. 012039
Author(s):  
Xiaoyue Wang ◽  
Liang Cai ◽  
Yanqin Mao ◽  
Wanjun Guo

Abstract Considering the end effect, the three-dimensional finite element calculation model of the magnetic coupling is established. The three-dimensional distribution nephogram of the induced current and eddy current loss on the isolation cover is obtained, and the distribution trends of the two are consistent. The influence of size, material, and operating condition of magnetic coupling on eddy current loss is studied. The results show that the selection of isolation material with high resistivity and the reduction of isolation thickness are helpful to reduce the eddy current loss. The higher the rotating speed of the magnetic coupling, the greater the eddy current loss. At the same speed, the greater the load, the greater the magnetic declination, the smaller the eddy current loss. The research results can provide a reference for reducing energy loss and cooling structure design of magnetic coupling.


2020 ◽  
Vol 64 (1-4) ◽  
pp. 157-163
Author(s):  
Koki Ito ◽  
Takahisa Kadomatsu ◽  
Kohei Obana ◽  
Kenji Nakamura

This paper deals with development of in-wheel magnetic-geared motor for walking support machines. In a previous paper, a magnetic-geared motor for a walking support machine was prototyped. However, its efficiency was low, therefore improving the efficiency is necessary for practical use. This paper presents the improving efficiency of the magnetic-geared motor from the viewpoint of torque increasing and loss reducing by using a three-dimensional finite element method (3D-FEM). In addition, supporting method of pole-pieces and eddy current loss in housing were discussed. Furthermore, the proposed motor is prototyped. The experimental results show that its efficiency is 15% higher than the previous motor. Finally, the walking support machine installed with two magnetic-geared motors is prototyped and demonstrated.


2013 ◽  
Vol 49 (5) ◽  
pp. 2033-2036 ◽  
Author(s):  
Paul Handgruber ◽  
Andrej Stermecki ◽  
Oszkar Biaro ◽  
Georg Ofner

Author(s):  
Ming Li ◽  
Yuejun An ◽  
Zhiheng Zhang ◽  
Wenyu Deng ◽  
Guangyu Wang ◽  
...  

Canned induction motors fed by inverters are widely used in pharmaceutical, chemical, and nuclear fields. It is necessary to analyse the effect of time harmonic injected by the inverter on the performance of the canned induction motor. However, the existing researches are to consider the inverter and the motor separately, without analyzing the reverse effect of the induction motor as a nonlinear active load on the time harmonics of the inverter. Therefore, this paper establishes a field-circuit coupling analysis model of the canned induction motor considering the influence of load, and studies the effect of time harmonic current under different load conditions on the electromagnetic field, eddy current loss, and temperature field of the canned induction motor. The paper first uses the analysis method to determine the relationship between the time harmonic voltage of the inverter and the time harmonic current of the motor. Then, the electromagnetic field distribution, eddy current loss, and temperature field distribution of the canned induction motor under different load conditions are calculated. Besides, the laws of time harmonic current on the electromagnetic field, can loss and motor temperature distribution are found. These research results can not only provide a meaningful reference for analysis of the canned induction motor but also provide methods for design optimization and multi-physical field modeling analysis of the canned induction motor.


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