Other Factors Contributing to the Core Loss Performance of Power and Distribution Transformers

2001 ◽  
Vol 21 (7) ◽  
pp. 70-70
Author(s):  
E. TeNyenhuis ◽  
R. Girgis ◽  
G. Mechler
Keyword(s):  
Core Loss ◽  
The Core ◽  
Distribution Transformers

Epstein frame investigation on soft magnetic properties of Fe-based amorphous strips

2021 ◽  
Vol 63 (10) ◽  
pp. 604-609
Author(s):  
Yanxing Xing ◽  
Shaoxiong Zhou ◽  
Wenzhi Chen ◽  
Bangshao Dong ◽  
Yaqiang Dong ◽  
...  
Keyword(s):  
High Efficiency ◽  
Core Loss ◽  
Core Material ◽  
Test Results ◽  
The Core ◽  
Distribution Transformers ◽  
Core Losses ◽  
Power Frequency ◽  
Field Annealing ◽  
Frame Method

Fe-based amorphous strip (AM strip) is a core material for high-efficiency distribution transformers and contributes to saving energy loss in electricity distribution. The core loss and apparent power for 2605SA1 amorphous strips at power frequency are studied using the Epstein frame method. Longitudinal magnetic field annealing and the influence of measuring modes on test results are investigated in detail. Improved test efficiency and higher accuracy in test results for amorphous ribbons are demonstrated and it is found that the number of strips and the lap joint methods affect the test results greatly. The waveform of the secondary induction voltage becomes sinusoidal with the increase of strip number. The values of core loss and apparent power become stable once the total number of strips is larger than 20. The coefficient of eddy current loss (e) also affects the correction of testing core losses. The test results could be improved at a smaller value of e when the waveform of the secondary induction voltage becomes deformed from sinusoidal due to a lower number of strips (below 20). The measured results were found to be reproducible when the strip number of each layer was one or two. However, the core loss and the apparent power increased along with the increase in the number of strips in each layer. Moreover, demagnetisation showed no effects on the test results when using the Epstein frame method.

Calculation and validation of iron loss in laminated core of power and distribution transformers

2013 ◽  
Vol 33 (1/2) ◽  
pp. 137-146 ◽  
Author(s):  
Xiaoyan Wang ◽  
Zhiguang Cheng ◽  
Li Lin ◽  
Jianmin Wang
Keyword(s):  
Magnetic Flux ◽  
Flux Density ◽  
Core Loss ◽  
Iron Loss ◽  
Magnetic Flux Density ◽  
Content Type ◽  
The Core ◽  
Distribution Transformers ◽  
The Impact ◽  
Transformer Core

Purpose – The purpose of this paper is to present a simple method to analyze the iron loss in the laminated core of power and distribution transformers. Design/methodology/approach – This paper presents a practical method to calculate the no-load loss in the transformer cores. Considering the non-uniformity of the magnetic flux density in the corner areas of the Epstein frames will affect the measurement precision of the Wt-B curves then further affect the core loss calculation in FEM, a dual-Epstein frame method is used to measure the Wt-B curves with the Epstein sample stripes cutting by different angles to the rolling direction. A 2D FEM that considers the type of joints of the core and eddy current effect in the laminations is used to analyze the core loss with multi-angle Wt-B curves. Findings – The impact of lamination thickness, size of gaps and type of joint of the core are considered. Considering the no-load testing conditions, harmonics in the exciting currents are taken into account. Originality/value – Harmonic wave of magnetic flux density in the transformer core is calculated and the core loss in the joint region is calculated by the loss curve measured with dual-Epstein frame. It makes the calculation result of transformer core loss more exactly.

Other factors contributing to the core loss performance of power and distribution transformers

2001 ◽  
Vol 16 (4) ◽  
pp. 648-653 ◽  
Author(s):  
Ed.G. teNyenhuis ◽  
R.S. Girgis ◽  
G.F. Mechler
Keyword(s):  
Core Loss ◽  
The Core ◽  
Distribution Transformers

scholarly journals Reducing the core loss of amorphous cores for distribution transformers

2012 ◽  
Vol 22 (3) ◽  
pp. 244-249 ◽  
Author(s):  
Deren Li ◽  
Liang Zhang ◽  
Guangmin Li ◽  
Zhichao Lu ◽  
Shaoxiong Zhou
Keyword(s):  
Core Loss ◽  
The Core ◽  
Distribution Transformers

scholarly journals Core Stress Analysis of Amorphous Alloy Transformer for Rail Transit under Different Working Conditions

Energies ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 164
Author(s):  
Jianwei Shao ◽  
Cuidong Xu ◽  
Ka Wai Eric Cheng
Keyword(s):  
Amorphous Alloy ◽  
Working Conditions ◽  
Short Circuit ◽  
Element Model ◽  
Operating Conditions ◽  
Iron Core ◽  
Rail Transit ◽  
Transit System ◽  
The Core ◽  
Distribution Transformers

The rail transit system is a large electric vehicle system that is strongly dependent on the energy technologies of the power system. The use of new energy-saving amorphous alloy transformers can not only reduce the loss of rail transit power, but also help alleviate the power shortage situation and electromagnetic emissions. The application of the transformer in the field of rail transit is limited by the problem that amorphous alloy is prone to debris. this paper studied the stress conditions of amorphous alloy transformer cores under different working conditions and determined that the location where the core is prone to fragmentation, which is the key problem of smoothly integrating amorphous alloy distribution transformers on rail transit power supply systems. In this study, we investigate the changes in the electromagnetic field and stress of the amorphous alloy transformer core under different operating conditions. The finite element model of an amorphous alloy transformer is established and verified. The simulation results of the magnetic field and stress of the core under different working conditions are given. The no-load current and no-load loss are simulated and compared with the actual experimental data to verify practicability of amorphous alloy transformers. The biggest influence on the iron core is the overload state and the maximum value is higher than the core stress during short circuit. The core strain caused by the side-phase short circuit is larger than the middle-phase short circuit.

scholarly journals Anisotropy of Magnetic Properties in Non-oriented Electrical Steel Sheets

1989 ◽  
Vol 11 (2-4) ◽  
pp. 159-170 ◽  
Author(s):  
M. Shiozaki ◽  
Y. Kurosaki
Keyword(s):  
Magnetic Properties ◽  
Magnetic Induction ◽  
Crystallographic Orientation ◽  
Electrical Steel ◽  
Core Loss ◽  
Fluorescent Lamp ◽  
Steel Sheets ◽  
The Core ◽  
Texture Change ◽  
Electrical Steel Sheets

The anisotropy of magnetic properties in non-oriented electrical steel sheets can be evaluated by measuring Epstein specimens in the radial directions. The magnetic properties measured on ring cores are practically equal to the approximate values of magnetic properties determined by Epstein specimens in the radial directions. Non-oriented electrical steel sheets with anisotropy are not desirable for motors but are suitable for transformers and fluorescent lamp ballasts. The core loss and magnetic induction as measured with ring specimens are better with non-oriented electrical steel sheets with anisotropy than with non-oriented electrical steel sheets with random crystallographic orientation. This phenomenon depends on the texture change of the product.

scholarly journals Impact of addition of ca on clogging of SEN and magnetic properties of non-oriented silicon steel

2019 ◽  
Vol 55 (1) ◽  
pp. 39-46
Author(s):  
W. Kong ◽  
D.G. Cang
Keyword(s):  
Magnetic Properties ◽  
Continuous Casting ◽  
Casting Speed ◽  
Magnetic Induction ◽  
Core Loss ◽  
Submerged Entry Nozzle ◽  
Silicon Steel ◽  
The Core ◽  
Dissolved Aluminum ◽  
The Impact

The submerged entry nozzle (SEN) clogging has been happening during continuous casting (or CC for short) for nonoriented silicon steel. To solve the problem, the paper studied a flow rate through SEN, a node attached to one of them, and the impact on the clogging. The results showed that when SEN is clogged seriously, the casting speed has to decrease below the target casting speed and that SEN clogging can be predicted by comparing the actual value and the theoretical one of a casting speed. Al2O3 and its composite inclusions caused the SEN clogging and the addition of Ca can solve SEN clogging during CC of the silicon steel both theoretically and practically. Furthermore, the impact of the addition of Ca on the magnetic properties of the steel were analyzed. The results showed that the core loss and the magnetic induction of the silicon steel decreased by using the addition of Ca, which generated more dissolved Aluminum, and the addition of Ca generated more harmful textures, which reduced the magnetic induction.

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