Modeling of the air-gaps of overlapped joints in three-phase transformer iron core for using by FEM

Author(s):  
M. Khelil ◽  
M. Elleuch
Keyword(s):  
Air Gaps ◽  
2017 ◽  
Vol 3 (2) ◽  
pp. 88
Author(s):  
Suci Rahmatia ◽  
Marsah Zaysi Makhudzia

<p><em>Abstrak <strong>- </strong></em><strong>Transformator adalah peralatan listrik yang sangat vital dalam proses pembangkitan maupun transmisi energi listrik karena transformator dapat menaikkan atau menurunkan tegangan. Pada proses menaikkan dan menurunkan tegangan biasanya sering timbul panas akibat rugi – rugi tembaga pada inti besi dan kumparannya sehingga pada kondisi overload akan menimbulkan pemanasan yang berlebih dan dapat mempengaruhi kinerja transformator. Oleh karena itu dibuat sistem kontrol temperatur pada transformer yang dapat mengontrol temperatur di dalam transformator saat bekerja pada kondisi overload, sehigga transformatornya tidak terbakar. Dial thermometer digunakan sebagai alat yang mengontrol temperatur transformator pada sistem kontrol temperatur. Agar mendapatkan sistem kontrol yang optimal, maka setting temperatur pada dial thermometer di sesuaikan dengan temperatur maksimal tranformator dapat bekerja. Sehingga pada saat temperatur tertentu dial thermometer dapat memberikan sinyal untuk membunyikan alarm dan mengaktifkan kontrol kipas sehingga kipas dapat bekerja menurunkan temperatur transformator.<em></em></strong></p><p><strong><em> </em></strong></p><p><strong><em>Kata kunci - </em></strong><em>transformator, rugi – rugi tembaga, temperatur, sistem kontrol, dial thermometer<strong>.</strong></em></p><p><strong><em> </em></strong></p><p><em>Abstract <strong>- </strong></em><strong>A transformer is an electrical device that is vital in the generation and transmission of electrical energy because the transformer can raise (stepping up) or lower (stepping down) the voltage. In the process of raising and lowering the voltage is usually often caused heat loss of copper in iron core and coil so that the overload condition will cause excessive warming and can affect the performance of the transformer. Therefore, a temperature control system on the transformer can control the temperature inside the transformer while working under overload conditions, so the transformer is not burned. Dial thermometer is used as a device that controls the temperature of the transformer in the temperature control system. In order to obtain an optimal control system, the temperature setting on the dial thermometer adjusted to the maximum transformer temperature can work. So that when a certain temperature dial thermometer can provide a signal to sound the alarm and activate the fan control so that the fan can work down the transformer temperature.</strong></p><p><strong> </strong></p><p><strong><em>Keywords -  </em></strong><em>transformator, loss of copper, themperature, control system, dial thermometer<strong></strong></em></p>


2020 ◽  
pp. 1-1
Author(s):  
Yanhui Gao ◽  
Shuhei Ichimaru ◽  
Toshihisa Miyabe ◽  
Hiroshi Dozono ◽  
Kazuhiro Muramatsu ◽  
...  

2013 ◽  
Vol 325-326 ◽  
pp. 519-524
Author(s):  
Lian Liu ◽  
Qiong Lin Li ◽  
Hui Jin Liu ◽  
Xue Cui ◽  
Lei Zou

Beginning with characterizing the nonlinearities of transformer, this paper uses the J-A model to represent the hysteresis of iron core, and fits the model in calculating exciting current. Compared with the other methods, such as polynomial and describing function method, J-A model is more capable in representing nonlinearity, so the calculated current would be more accurate. Then, after analyzing Maxwell equations that meet certain boundary conditions, the paper considers comprehensively the effects of skin and proximity, and then obtains the computing way of ac resistance under harmonics. At last, based on the mentioned results, paper proposes a set of three-phase transformer model which could calculate harmonic losses. The proposed model is a kind of combined time-and frequency-domain model that possesses good convergence. The introduced example has verified the correctness and effectiveness of the model which absolutely suits the engineering applications.


2016 ◽  
Vol 24 (11) ◽  
pp. 2761-2768
Author(s):  
宫宁宁 GONG Ning-ning ◽  
高春甫 GAO Chun-fu ◽  
李熹平 LI Xi-ping

2015 ◽  
Vol 51 (1) ◽  
pp. 1-4 ◽  
Author(s):  
Klemen Dezelak ◽  
Martin Petrun ◽  
Miran Roser ◽  
Drago Dolinar ◽  
Gorazd Stumberger

1976 ◽  
Vol 29 (2) ◽  
pp. 1 ◽  
Author(s):  
RL Dewar

The effect of an iron transformer core on the field of a current loop is examined for two models of the core: (1) An infinite straight rod of high permeability aligned along the axis of symmetry, for which asymptotic expressions for the effect of the core are obtained and compared with numerical results. (2) A rectangular toroidal iron casing surrounding the loop. The latter model is more realistic because a return path is provided for the flux. For this model, the effect of air gaps is considered, and rapidly convergent series are obtained and numerical results are given. The significance of these results for tokamak equilibrium is indicated.


2021 ◽  
Vol 18 (1) ◽  
pp. 26-35
Author(s):  
Mohamed ELADAWY ◽  
Ibrahim Metwally

This paper proposes an improvement for the dynamic performance of presaturated stacked permanent magnet biased three-phase fault current limiter (PMFCL) through COMSOL finite element simulation. The nonlinear demagnetization behavior of the permanent magnet, especially in the upper part of the B-H curve with negative magnetic field intensity, has been modelled through the Jiles-Atherton method. This enables a realistic representation of the PMFCL dynamic behavior throughout its entire operations of pre-fault, fault and fault removal, respectively. The experimental measurements have been considered to validate the trends of the simulation outcomes during the entire operation of PMFCL. Extensive finite element simulation shows that the stacked design of PMFCL can increase the capability of fault current limiting with proper selection of the number and arrangement of the AC coils around the iron core (soft magnet). Results reveal that the division of AC coils into series differential connected subcoils, with an even number, can increase the limiting capability with increasing the AC coil number of turns, without exceeding the permissible tolerances of voltage drop and power losses. Moreover, this stacked design is subjected to parametric investigation for different fault types, either symmetrical or unsymmetrical, or even when changing the fault current peak value.


Author(s):  
Tu Pham Minh ◽  
Hung Bui Duc ◽  
Thinh Tran Van ◽  
Dung Dang Chi ◽  
Vuong Dang Quoc
Keyword(s):  
Air Gaps ◽  

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