A multi-step approach for the fast calculation of the magnetic field inside transformer tank shields, based on the 2D FEM, is presented in the paper. Due to the limitations of the 2D FEM, the ...proposed approach utilizes several 2D FEM models and calculates the magnetic field in multiple steps to account for the 3D geometry of the problem. In the first step, a distribution of the magnetic flux density that enters the tank shields is calculated using the quasi-3D model of the transformer. This quasi-3D model is obtained by superimposing the solution of multiple axisymmetric 2D FEM models, and assumes a considerably simplified transformer geometry. To account for the tank shield geometry that is neglected in the quasi-3D FEM model, an additional 2D FEM model with tank shields is introduced. After the distribution of the magnetic flux density that enters the tank shields is calculated, it is imposed in the final 2D FEM model with a non-linear tank shield which is used to calculate the magnetic flux density distribution inside the tank shields. The proposed approach enables a fast calculation of magnetic field distributions, both in the vertical and horizontal directions. The results of the proposed approach are compared against the 3D FEM. The relative error of the maximum magnetic flux density is under 2%, while the NRMSE of the magnetic flux density distribution within the tank shields is under 10%. The key contribution of the proposed approach is a low computation time. In the presented case study, the total computation time of the proposed approach is ~30 s, while the computation time of the 3D FEM is ~1 h. As the computation time is significantly reduced, while the accuracy is acceptable, the proposed approach can be a good alternative to the 3D FEM for design purposes. Therefore, it has industrial value.
•A figure that explains quasi-3D model geometry, is improved.•The general information about used transformers is added to the paper.•A third example of a transformer, with detailed geometry ...information, is added to the paper, which allows the reader to reproduce the result.
The multi-step approach for the calculation of magnetic field in a power transformer yoke shunt is proposed in the paper. This approach can be used as an alternative to the time-consuming 3D FEM modelling when a fast calculation is needed – e.g. optimization of transformer geometry during the design process. A single 2D FEM model can not be used for the calculation of the magnetic field in the yoke shunt. Therefore, the magnetic field is calculated in steps, using multiple 2D FEM models. The proposed approach is tested on two examples of real power transformer geometries. The validity of the approach is verified using the results of the 3D FEM calculations. In the worst case, the maximum value of the magnetic flux density, calculated using the proposed multi-step approach, deviates by 6% from 3D FEM. The main advantage of the proposed approach is significantly reduced computation time from several hours for 3D FEM to less than a minute for the proposed approach.
Organizations cannot exist without communication. Every human action is a kind of communication, and thus “not communicating” is also a form of communication. Efficient communication is the ...foundation for the internal organization development, but also a key factor of existence in an uncertain environment. Therefore, communication is an important aspect of manager behaviour as well as of the functioning of the entire organizational system. Business communication takes place both within and outside of organizations. A communication event within an organization can have two routes:a formal and an informal one. To make the organizational communication more successful, it is necessary for all participants and organization employees to have adequate language skills, to conduct interactive exercises and to possess intercultural awareness.
Business communication is a very important part of any business, organization and management system, while information technology merges microelectronics, computers, telecommunications and ...software,thus facilitating the input, processing and distribution of information. Information technology is one of the key generic technologies because it has entered all spheres of economic, scientific, social and private life and has brought with it radical changes. Different information technologies and communication are closely linked. The new business communication using Web 2.0 technology defines active factors in a completely new business communication environment. For the new approach to business communication to be effective, a good knowledge of various communication technologies is required. The aim of this paper is to present contemporary business communication and demonstrate how much information technology affects business communication using a practical example (private business).
Organizations cannot exist without communication. Every human action is a kind of communication, and thus “not communicating” is also a form of communication. Efficient communication is the ...foundation for the internal organization development, but also a key factor of existence in an uncertain environment. Therefore, communication is an important aspect of manager behaviour as well as of the functioning of the entire organizational system. Business communication takes place both within and outside of organizations. A communication event within an organization can have two routes: a formal and an informal one. To make the organizational communication more successful, it is necessary for all participants and organization employees to have adequate language skills, to conduct interactive exercises and to possess intercultural awareness.
Application of the Taguchi methods results in efficient optimization of performance, quality and price, fast and accurate gathering of technical information, design and production of highly reliable ...products and processes at low prices, development of flexible technologies for designing of a whole group of high quality associated products. All this significantly reduces the duration of research, development and delivery. The most frequent use of the Taguchi methods is to improve existing products and production processes and to reduce the need for experiments. The Taguchi methods is a system of quality engineering which puts more emphasis on reduction of production costs and giving advantage to efficient use of engineering strategies than on the use of advanced statistical methods.
Business communication is a very important part of any business, organization and management system, while information technology merges microelectronics, computers, telecommunications and software, ...thus facilitating the input, processing and distribution of information. Information technology is one of the key generic technologies because it has entered all spheres of economic, scientific, social and private life and has brought with it radical changes. Different information technologies and communication are closely linked. The new business communication using Web 2.0 technology defines active factors in a completely new business communication environment. For the new approach to business communication to be effective, a good knowledge of various communication technologies is required. The aim of this paper is to present contemporary business communication and demonstrate how much information technology affects business communication using a practical example (private business).
Stray flux in a transformer enters the outer packages of a core perpendicularly and induces significant eddy currents that cause ohmic losses. Local thermal conditions near the core are affected by ...these losses that are dissipated as heat and can cause local overheating in the oil near the outer packages. Stray losses in the outer packages should be considered during the power transformer design process, and it is, therefore, important to model them properly. This type of loss can be solved using 3-D FEM; however, that approach is time-consuming, which makes it impractical for the loss calculation in real time. Another approach is 2-D modeling, which is faster, but it is limited to axisymmetric and planar geometries only. Due to its complex geometry, a transformer cannot be modeled using a single 2-D model. Instead, each quantity of interest, such as a magnetic field or eddy currents, can be obtained from a suitable model. These models include certain simplifications, which should not affect the accuracy of the results. In this article, a hybrid approach that utilizes various 2-D models for the calculation of stray losses in the outer packages is proposed. The advantage of the proposed methodology is in obtaining the same level of accuracy while considerably reducing the calculation time when comparing to the 3-D FEM approach. The estimation of the temperature rise of the outer packages, based on the calculated losses, will be a part of further research.
The paper describes a high-frequency model for transient calculation in transformer windings with segmentation on a turn level. The windings are represented by lumped RLC parameters given by the ...analytical approach, whereas the model is solved in the time domain. The accuracy of the analytical calculation is improved with correction factors obtained with a set of numerical calculations. The presented model is verified by measurements on the example of power transformer disc winding.
