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To determine the electrical field E₁(t) in spherical and cylindrical gas voids existing in an insulator by considering surface conductivity of gas voids having an electrical permittivity of ε₁ and conductivity of γ₁ for DC and AC situations.

Analytical expressions satisfying Laplace equation for inside and outside of the cylindrical and spherical gas voids in an insulator located in an external electrical field having a definite time dependent character, have been derived by considering the surface conductivity of the gas void. The coefficients included by these analytical expressions have been determined by utilizing the continuity equation of the current on the surface of the voids.

It has been demonstrated that the electrical field remains uniform in spherical and cylindrical gas voids when the surface conductivity of gas void has been considered. It has been determined that the contact charging process of different shaped particles has an exponential characteristic, and some expressions have been derived to determine the time constants of this process for practical purposes.

The results have been applied to the problems about contact charging of semi‐spherical and semi‐cylindrical insulated particles located at a charged surface and problems about the calculation of onset discharging voltage of ionization process in dielectric including gas voids.

For spherical and cylindrical gas voids, the onset discharging voltage corresponding to the ionization process occurring in gas voids has increased by increasing the surface conductivity of the void. For the limit value of the surface conductivity, the voids in the insulator behaves like metal particles distributed into the insulator, for this reason, at the outside of the void, especially in the regions where the voids are close to the electrodes and each other, the electrical field will be non‐uniform and will increase. This situation will cause the ignition of the partial discharge and destroy to the insulator.

Gives introductory remarks about chapter 1 of this group of 31 papers, from ISEF 1999 Proceedings, in the methodologies for field analysis, in the electromagnetic community. Observes that computer package implementation theory contributes to clarification. Discusses the areas covered by some of the papers ‐ such as artificial intelligence using fuzzy logic. Includes applications such as permanent magnets and looks at eddy current problems. States the finite element method is currently the most popular method used for field computation. Closes by pointing out the amalgam of topics.

Discusses the 27 papers in ISEF 1999 Proceedings on the subject of electromagnetisms. States the groups of papers cover such subjects within the discipline as: induction machines; reluctance motors; PM motors; transformers and reactors; and special problems and applications. Debates all of these in great detail and itemizes each with greater in‐depth discussion of the various technical applications and areas. Concludes that the recommendations made should be adhered to.

This study aims to present a numerical analysis of the behavior of the electric field and flow field characteristics under electrohydrodynamics (EHD) force. The influence of the jet airflow under the EHD force is investigated when it impacts the inclined flat plate.

The high electrical voltage and angle of an inclined flat plate are tested in a range of 0–30 kV and 0–90^°, respectively. In this condition, the air is set in a porous medium and the inlet jet airflow is varied from 0–2 m/s.

The results of this study show that the electric field line patterns increase with increasing the electrical voltage and it affects the electric force increasing. The angle of inclined flat plate and the boundary of the computational model are influenced by the electric field line patterns and electrical voltage surface. The electric field pattern is the difference in the fluid flow pattern. The fluid flow is more expanded and more concentrated with increasing the angle of an inclined flat plate, the electrical voltage and the inlet jet airflow. The velocity field ratio is increased with increasing the electrical voltage but it is decreased with increasing the angle of the inclined flat plate and the inlet jet airflow.

The maximum Reynolds number, the maximum velocity field and the maximum cell Reynolds number are increased with increasing the electrical voltage, the inlet jet airflow and the angle of the inclined flat plate. In addition, the cell Reynolds number characteristics are more concentrated and more expanded with increasing the electrical voltage. The pattern of numerical results from the cell Reynolds number characteristics is similar to the pattern of the fluid flow characteristics. Finally, a similar trend of the maximum velocity field has appeared for experimental and numerical results so both techniques are in good agreement.

This paper aims to present simulation studies on voltage and electric field characteristics for imperfect ceramic insulators using QuickField^TM software. Based on previous studies, it is accepted that string insulator can still serve the transmission line although imperfect of certain insulator exist in a string. However, different materials of porcelain and glass type had made these insulators own different abilities to carry electricity to be transferred to the consumers.

Cap and pin type of porcelain and glass insulators are used as the main subject for comparison. The simulation works begins with modeling a single insulator, followed by string of ten insulators with their respective applied voltage, that is, 11 and 132 kV. The insulator was modeled in alternate current conduction analysis problem type using QuickField Professional Software. Technical parameters for porcelain and glass insulator were manually inserted in the modeling.

This paper presents an investigation on the influence of broken porcelain and glass insulators in string for voltage and electric field characteristics. For single insulator, the voltage distribution may literally reduce when experiencing external damages; whereby the broken porcelain insulator condition is worse than the glass insulator. In terms of electric field distribution, the glass insulator is badly affected compared with the porcelain insulator, as it is pulverized comprehensively.

Further work needs to be done to establish whether the experiments of these simulations study will present coequal outcomes. This study endeavors in promoting a good example of voltage and electric field characteristics across high voltage (HV) insulator with the presence of broken insulator in the string.

This study is beneficial to future researchers and manufacturing companies in strategic management and research planning when they involve in the field of HV insulators. It will also serve as a future reference for academic and study purposes. This research will also educate many people on how HV insulators work.

This study will be helpful to the industry and business practitioners in training for the additional results and knowledge to be updated in the area of HV insulators.

This paper presents the analysis of porcelain and glass insulators according to their respective logic conditions when broken. Consequently, the existence of a damage insulator in a string may alter the distribution of voltage and electric field which may ultimately lead to the insulation breakdown after some time. This is because the broken insulator may cause other insulators to withstand the remaining voltage allocated for that particular insulator and may affect the insulators in terms of the life span. Therefore, the distribution of voltage and electrical field characteristics in the presence of broken insulators had been studied in this project.

The purpose of this paper is to present a new calculation method for increasing the shielded volume in which the external electromagnetic field is maximally reduced. In a space shielded in the way mentioned in this paper, it is possible to introduce measurement instruments and increase the accuracy of results obtained with them, as well as reduce the risk of unwanted electrostatic field influence on living organisms.

A new numerical procedure for the optimization of the coaxial ring conductor system for electrostatic shielding is developed in the paper. The optimization of the functional that consists of electrostatic energy density and a system of equations derived from the equipotential character of the conductor system is used. The system of nonlinear equations is obtained and then numerically solved by minimizing this functional. The first presented optimization procedure is based on the analytical optimization method using the Lagrange coefficients and gradient of the objective function.

It is possible to design a large number of protective ring formations. Applying the differential evolution optimization method, an optimal arrangement can be obtained for any specific number of rings. The differential evolution optimization method, which belongs to the class of evolutionary algorithms, is used for solving this very complex optimization problem. In combination with the above-mentioned method, excellent results in the elimination of the external electric field have been obtained. Although a larger number of rings provides more efficient protection, this number is limited from the economic point of view. Therefore, it is necessary to achieve a compromise between the number of rings, the size of volume shielded and the quality of protection.

There are few papers that address this problem, although the elimination of the influence of the external electromagnetic field has gained more importance lately. The presented method can be applied to increase the reliability of measured data, protection of the environment, in space research, etc. The main limiting factor for using a larger number of rings that provide better protection is the economical one.

The proposed method is suitable for the generalization of procedures, for the protection of the space where the external electric field needs to be reduced or eliminated.

Introduces the fourth and final chapter of the ISEF 1999 Proceedings by stating electric and magnetic fields are influenced, in a reciprocal way, by thermal and mechanical fields. Looks at the coupling of fields in a device or a system as a prescribed effect. Points out that there are 12 contributions included ‐ covering magnetic levitation or induction heating, superconducting devices and possible effects to the human body due to electric impressed fields.

The purpose of this paper is to develop a numerical simulation method based on the transient upstream finite element method (FEM) and Schottky emission theory to reveal the distribution characteristics of space charge in oil-paper insulation.

The main insulation medium of the converter transformer in high voltage direct current transmission is oil-paper insulation. However, the influence of space charge is difficult to be fully considered in the insulation design and simulation of converter transformers. To reveal the influence characteristics of the space charge, this paper proposes a numerical simulation method based on Schottky emission theory and the transient upstream FEM. This method considers the influence of factors, such as carrier mobility, carrier recombination coefficient, trap capture coefficient and diffusion coefficient on the basis of multi-physics field coupling calculation of the electric field and fluid field.

A numerical simulation method considering multiple charge states is proposed for the space charge problem in oil-paper insulation. Meanwhile, a space charge measurement platform based on the electrostatic capacitance probe method for oil-paper insulation structure is built, and the effectiveness and accuracy of the numerical simulation method is verified.

A variety of models are calculated and analyzed by the numerical simulation method in this paper, and the distribution characteristics of the space charge and total electric field in oil-paper insulation medium with single-layer, polarity reversal of plate voltage and double-layer are obtained. The research results of this paper have the guiding significance for the engineering application of oil-paper insulation and the optimal design of converter transformer insulation.

Underground cables can produce higher electromagnetic fields directly above them than an overhead line. The majority of cable failures on distribution system are caused by defects in the cable accessories. Nowadays, significant research has been carried out worldwide into examining whether electricity, and in particular, the presence of electric and magnetic fields have an adverse impact on health, especially the occurrence of cancer and childhood leukemia. The purpose of this paper is to optimize the electric field distribution in underground cable accessories. This reduces the impact of the harmful effects of the fields on living beings and humans.

Cable terminations and joints are designed to eliminate the stress concentration at the termination screen to avoid the breakdown of the cable and high values of electric field at these points. Any improvement in the cable termination and joints construction is of great interest. There are several methods for the solution of electric field distribution. These can be summarized as analytical, experimental, free-hand field mapping, analogue methods and numerical methods. In this paper cable accessories are modeled by using multilayer dielectric system and very thin deflector’s cones.

This model includes specific insulators design and smart choice of electrodes position. Stress-grading nonlinear materials in form of tapes and tubes were used with much success. In order to optimize the cable joint parameters, two criteria were monitored – total electric field magnitude and magnitude of the tangential component. More than 30 percent is reduced impact of cables on the environment.

In order to investigate the accuracy of the applied numerical model, various configurations of the cable accessories are studied. The first time is applied new Hybrid Boundary Elements Method on the protection of the environment.

The purpose of this paper is to investigate how the new theory on the general systemic yoyos can be plausibly employed to provide novel explanations for some of the well‐known laboratory experiments of physics and how a different theory that is more refined than the currently accepted theories can be established for illustrating phenomena that have not been completely explainable by using the traditional theories.

The general field structures of systemic yoyos, combined with some of the well‐known laboratory observation of physics, are employed as the basic methodology for the current paper.

Owing to the co‐existence of magnetic fields and ring‐shaped negative electric fields, all possible ways for an electromagneton to be fired into a stable, uniform‐intensity magnetic field are investigated. How such an electromagneton could be traveling under the mutual influence of the fields is described with details.

The value of this paper lies on the fact that it points out a brand new and practically applicable theory for looking at some of the well‐recorded phenomena of electromagnetism.