Zero phase sequence impedance and tank heating model for three phase three leg core type power transformers coupling magnetic field and electric circuit equations in a finite element software

The ellipsoidal magnetization model has a wide range of application scenarios. For example, in aviation magnetic field prospecting, mineral prospecting, seabed prospecting, and UXO (unexploded ordnance) detection. However, because the existing ellipsoid magnetization formula is relatively complicated, the detection model is usually replaced by a dipole. Such a model increases the error probability and poses a significant challenge for subsequent imaging and pattern recognition. Based on the distribution of ellipsoid gravity potential and magnetic potential, the magnetic anomaly field distribution equation generated by the ellipsoid is deduced by changing the aspect ratio, making the ellipsoid equivalent to a sphere. The result of formula derivation shows that the two magnetic anomaly fields are consistent. This paper uses COMSOL finite element software to model UXO, ellipsoids, and spheres and analyzes magnetic anomalies. The conclusion shows that the ellipsoid model can completely replace the UXO model when the error range of 1nT is satisfied. Finally, we established two sets of ellipsoids and calculated the magnetic anomalous field distributions on different planes using deduction formulas and finite element software. We compared the experimental results and found that the relative error of the two sets of data was within [Formula: see text]‰. Error analysis found that the error distribution is standardized and conforms to the normal distribution. The above mathematical analysis and finite element simulation prove that the calculation method is simple and reliable and provides a magnetic field distribution equation for subsequent UXO inversion.

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A zero-phase-sequence protection device for the internal fault in three-phase synchronous machines

Electrical Engineering in Japan ◽

10.1002/eej.4391010112 ◽

1981 ◽

Vol 101 (1) ◽

pp. 80-87

Author(s):

Koreyasu Kobayashi ◽

Kazuo Sato ◽

Masaki Miyazawa

Keyword(s):

Synchronous Machines ◽

Protection Device ◽

Internal Fault ◽

Phase Sequence ◽

Three Phase ◽

Zero Phase

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Three- and Two-Dimensional Finite-Element Computation of Inrush Current and Short-Circuit Electromagnetic Forces on Windings of a Three-Phase Core-Type Power Transformer

IEEE Transactions on Magnetics ◽

10.1109/tmag.2008.917819 ◽

2008 ◽

Vol 44 (5) ◽

pp. 590-597 ◽

Cited By ~ 51

Author(s):

J. Faiz ◽

B.M. Ebrahimi ◽

T. Noori

Keyword(s):

Finite Element ◽

Power Transformer ◽

Short Circuit ◽

Inrush Current ◽

Two Dimensional ◽

Three Phase ◽

Dimensional Finite Element ◽

Element Computation ◽

Type Power ◽

Finite Element Computation

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Performance Comparison of Multi Design Method and Meta-Heuristic Methods for Optimal Preliminary Design of Core-Form Power Transformers

Periodica Polytechnica Electrical Engineering and Computer Science ◽

10.3311/ppee.10207 ◽

2017 ◽

Vol 61 (1) ◽

pp. 69-76 ◽

Cited By ~ 2

Author(s):

Tamás Orosz ◽

Bence Borbély ◽

Zoltán Ádám Tamus

Keyword(s):

Optimization Problem ◽

Power Transformer ◽

Design Method ◽

Power Transformers ◽

Design Stage ◽

Preliminary Design ◽

Grey Wolf ◽

Grey Wolf Optimization ◽

Three Phase ◽

Type Power

Large power transformers are regarded as crucial and expensive assets in power systems. Due to the competing global market, to make a good and competing power transformer design, a non-linear optimization problem should be solved in a very short time in the preliminary design stage. The paper shows and compares the performance of four different methods to solve this problem for three phase core type power transformers. The first algorithm is a novel meta-heuristic technique which combines the geometric programming with the method of branch and bound. Then this conventional multi design method is solved by a simple iterative technique and two novel evolutionary algorithms to enhance the convergence speed. One of these algorithms is the particle swarm optimization technique which is used by many other researchers and the grey wolf optimization algorithm which is a new method in this optimization sub-problem. An example design on an 80 MVA, three phase core type power transformer using these four methods is presented and its performances are analyzed. The results demonstrate that the grey wolf optimization is a good alternative for this optimization problem.

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Finite Element Modeling and Analysis of Magnetorheological Dampers

Volume 7: Dynamic Systems and Control; Mechatronics and Intelligent Machines, Parts A and B ◽

10.1115/imece2011-63594 ◽

2011 ◽

Cited By ~ 2

Author(s):

David Case ◽

Behzad Taheri ◽

Edmond Richer

Keyword(s):

Magnetic Field ◽

Finite Element ◽

Magnetic Flux ◽

Weight Ratio ◽

Magnetorheological Damper ◽

Plastic Behavior ◽

Magnetorheological Dampers ◽

Flux Lines ◽

Finite Element Software ◽

Magnetic Flux Lines

A magnetorheological fluid consists of a suspension of microscopic magnetizable particles in a non-magnetic carrier medium. In the absence of a magnetic field, the fluid behaves in a roughly Newtonian manner. When a magnetic field is produced in the same space, the microscopic particles suspended in the fluid become oriented and form chains along the magnetic flux lines, changing the fluid’s rheology. The orientation of these particle chains is crucial to producing the Bingham plastic behavior necessary for high strength-to-weight ratio magnetorheological dampers and actuators. This project uses COMSOL Multiphysics finite element software to examine the magnetic flux lines, field intensity, and non-Newtonian fluid flow within a magnetorheological damper. Several established and novel damper configurations are examined and modified to improve performance while minimizing power draw of the electromagnet.

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