Papers by Cǎlin Munteanu
Technologies
The evaluation of human exposure to electric and magnetic fields represents a subject of great sc... more The evaluation of human exposure to electric and magnetic fields represents a subject of great scientific and public interest due to the biological effects of electromagnetic fields (EMFs) on the human body and the risks caused by them to living organisms. In this context, this article proposes a software program designed by the authors for the evaluation of human exposure to electric and magnetic fields at low frequencies (EMF software program), an application that can also be accessed from a mobile phone. The analytical model on which the EMF program is based is synthetically presented, and the application is then described. The first example implemented in the EMF program is taken from the existing literature on this subject, thus confirming the correctness and calculation precision of the program. Next, a case study is proposed for an overhead transmission line of 400 KV from the Cluj-Napoca area, Romania, for which the electric and magnetic fields are first measured experimenta...
EMC is concerned with the generation, transmission, and reception of electromagnetic energy. Thes... more EMC is concerned with the generation, transmission, and reception of electromagnetic energy. These three aspects of the EMC problem form the basic framework of any EMC design. A source (also referred to as an emitter) produces the emission, and a transfer or coupling path transfers the emission energy to a receptor (receiver), where it is processed, resulting in either desired or undesired behaviour. Interference occurs if the received energy causes the receptor to behave in an undesired manner. Antennas are especially the emitters of electromagnetic energy. This paper is about modelling and analyzing microstrip patch antennas. It contains the precise modelling of the antenna and the near field, far field, impedance and other characteristics of the antenna. After analyzing the near field and far field of the antenna, it can be optimized.
Environmental Engineering and Management Journal, 2013
The use of planar electromagnetic technology led to the improvement of high frequency characteris... more The use of planar electromagnetic technology led to the improvement of high frequency characteristics of the structures and the decrease of their size and profile, which made them easier to integrate in different devices. In order to improve these planar structures, it is known that the parasitic capacitance (EPC) must be decreased. Another method to achieve a better functionality is to increase or decrease the high frequency losses, according to their use. Because the previous studies were made on an EMI filter, it is known that in this case the HF losses must be increased. Because both of the mentioned methods are influenced by the shifting of the windings, this paper presents a study made in order to determine an optimum shifting which will lead to higher losses and lower EPC.
2017 12th International Conference on Live Maintenance (ICOLIM)
This paper proposes a general applicable numerical technique for the simulation of three-dimensio... more This paper proposes a general applicable numerical technique for the simulation of three-dimensional (3D) electrode shape changes obtained during the electroplating processes. The shape of the electrode is found displacing each mesh node proportional with, and in the direction of the local current density according to Faraday’s law. The local growth rate is obtained solving numerically the potential model using Boundary Element Method (BEM). An example dealing with the 3D simulation of electroplating near an insulator (singularity) is presented and compared with measurements and twodimensional (2D) simulations.
Electronics, 2021
This paper deals with high frequency analysis of spiral inductors, used in microelectronics circu... more This paper deals with high frequency analysis of spiral inductors, used in microelectronics circuits, to optimize their configuration. Software developed, designed, and implemented by the authors for nano and micrometre spiral inductor high frequency analysis, named ABSIF, is presented in this paper. ABSIF determines the inductance, quality factor, and electrical parameters for square, hexagonal, octagonal, and circular spiral inductors and their configuration optimization for energy efficiency. ABSIF is a good tool for spiral inductor design optimization in high frequency applications and takes into account the imposed technological limits and/or the designers’ constraints. A set of spiral inductors are considered and analysed for high frequency values using ABSIF, and the results are presented in the paper. The validation of ABSIF was completed by comparing the results with those obtained using a similar commercial software, Sonnet LiteTM, which is dedicated to high frequency elec...
Planar structures are often used recently due to their many advantages. Transformers, power induc... more Planar structures are often used recently due to their many advantages. Transformers, power inductors and EMI filters are only a few components that are constructed using this technique. In order to increase their efficiency, parasitic capacitance (EPC) must be decreases and HF losses must be appropriate to their utilisation. In previous studies it was discovered that a shifted winding of the planar structures decreases EPC.This paper represents a study which aims at finding an optimum shifting of the windings, wich will decrease EPC and increase HF losses.
2019 International Conference on Electromechanical and Energy Systems (SIELMEN), 2019
In the past, operation of automotive equipment was not susceptible to electromagnetic disturbance... more In the past, operation of automotive equipment was not susceptible to electromagnetic disturbances. Then with the increase in the number of electronic components and of electromechanical devices from automobiles which are operating at high frequencies, transient phenomena occur which produce electromagnetic interference that may influence the correct function of some equipment. So, immunity is the issue that needs to be considered and solved during the design of the automotive system. This paper presents a study that analyzes the importance of engine immunity used in automotive applications in accordance with EMC standards.
Spiral inductors are very often used in integrated circuits for many applications. To design spir... more Spiral inductors are very often used in integrated circuits for many applications. To design spiral inductors or to improve the spiral inductors performances is absolutely necessary to calculate theirs inductances and/or to optimize theirs layouts. In this effect we create a software program, named CIBSOC (Spiral Inductors Inductance Calculation and Layout Optimization). The program is dedicated to calculate dc inductances and to optimize layouts for spiral inductors. We use a wide range of inductors in the applications made with our program. We compare the results of our applications with the measurements results existing in the literature and also with the results that we have obtained using a commercial field solver in order to validate our program. Our program is accurate enough, has a very friendly interface, is very easy to use and it calculates the problems in a very sort running time compared with other similar programs. Since spiral inductors tolerance is generally on the o...
Improving the performances of a filter for conductive electromagnetic interferences suppression i... more Improving the performances of a filter for conductive electromagnetic interferences suppression involves two major directions of action: the first direction refers to the increase of attenuation at high frequency, while the second direction refers to the suppression of the parasitic effects in the constitutive devices. Thus, in this light, the paper presents the authors’ contribution to the two major directions of actions mentioned above; in the first part, techniques for HF loss increase are presented, while in the second part techniques for minimizing the structural parasitic capacitance are shown. In the third part of the paper these techniques are applied simultaneously to an EMI filter made in planar electromagnetic technology in order to study its performance.
Environmental Engineering and Management Journal, 2016
This paper presents an advanced numerical algorithm for the optimization of the current density d... more This paper presents an advanced numerical algorithm for the optimization of the current density distribution in electrochemical applications. The optimization principle consists in the distortion of the electric field by an insulating shield properly positioned between the electrodes. Such a distortion influences the distribution of current density at the electrodes under consideration. The electrochemical problem is approached by a Laplace equation which is numerically solved using a mesh-free algorithm based on the eXtended Finite Element Method (XFEM) while the optimal position of the insulating shield is managed by a genetic algorithm (GA). In order to reduce the computational time, two integration techniques were implemented in the XFEM algorithm: Gauss quadrature for the elements intersected by the discontinuity and natural coordinates for the other elements. The computational environment based on XFEM and GA was implemented in MatLab software. It can solve two dimensional (2D) and three dimensional (3D) applications and it was demonstrated on a practical electrochemical application for the optimization of current density distribution at the neighborhood between a cathode electrode in line with an insulator. The standard current density deviation at the cathode electrode is considerably reduced for optimal shield position comparing to the initial shield position. The use of the combined integration technique in the XFEM framework leads to an overall 70% improvement of the computational time compared with the standard XFEM integration technique.
Environmental Engineering and Management Journal, 2016
In order to limit personnel exposure to electromagnetic fields, safety standards provide among ot... more In order to limit personnel exposure to electromagnetic fields, safety standards provide among others, limitations in terms of induced currents in limbs, which is the measurable quantity allowing the evaluation of thermal load in limbs in the real conditions of electromagnetic radiofrequency exposure. Using a clamp-on current meter, eleven subjects were measured for current passing through their feet during the use of backpacked radio equipment, configured in various operating modes while using a monopole antenna of 122 cm length. Measurements were performed in the near-field zone of the radio source emitting electromagnetic fields of 30-108 MHz frequency, including indoor and outdoor measurement scenarios, as well as different working positions and operating modes. We have analyzed the way that induced current varies with respect to different exposure scenario variables to develop better understanding what parameters of exposure scenario have significant influence on limb thermal load in exposed person, what is useful in direct evaluation of exposure hazards, design of protection actions and validation of numerical models designed to mimic exposure scenario and evaluate thermal load by in-silico measurements (with respect to SAR values or limb currents). We have measured higher values of induced currents with indoor measurements (what indicate the elevated risk from exposure in multi-path propagation condition), for fixed frequency mode of emission and upright standing posture of user. We've also found that the height of exposed subject itself do not sufficiently characterize exposure scenario with respect to foot current inter-person variability.
Environmental Engineering and Management Journal, 2011
The paper focuses on the evaluation of the hazardous induced potentials on metallic pipelines tha... more The paper focuses on the evaluation of the hazardous induced potentials on metallic pipelines that convey fluids such as gas, petroleum, oil and shares the same right-of-way corridors with high voltage (HV) overhead power lines (OHL). For this purpose a dedicated computation software package was developed. The 3D numerical analysis of the AC electromagnetic interferences generated by the HV lines working on normal or fault conditions to the neighbor pipeline networks is based on a coupled Finite Elements (FEM)-Boundary Elements (BEM) model. In the first part of the paper the theoretical background is outlined and the problem governing equations are presented. Details about the 1D-FEM model developed for the interior of the pipeline and the 3D-BEM model setup for the pipeline external domain are emphasized. In the second part of the paper numerical computation examples are presented. The effect of a fault in the HV line circuit on the shape and magnitude of the hazardous induced potential distribution along the victim pipelines is detailed and discussed. The final conclusions end the paper.
Environmental Engineering and Management Journal, 2013
The paper outlines a technique to mitigate the power frequency magnetic field produced in its vic... more The paper outlines a technique to mitigate the power frequency magnetic field produced in its vicinity by the transport and distribution power lines. The technique consists in introduction below the line conductors of a passive loop of rectangular shape. Due to the induced currents in the rectangular frame, the total magnetic field below this structure is significantly reduced. The method's efficiency depends by the line conductor's configuration and also by the dimensions of the frame. The efficiency of the method can be improved by adding external capacitances to the passive loop. These external capacitances can lead to series resonance effect in the loop equivalent circuit that increases the value of the induced current flowing in the frame but they also enhance the induced current phase. Thus, in the first part of the paper the theoretical background is emphasized. Starting from Maxwell laws the expressions of the induced electromotive force in the frame structure and the corresponding current flowing through it are determined. Then the magnetic field computation formulae are outlined. Using these formulae one can compute the magnetic field values in points located below the power line, emphasizing the effect of the presence or not of the protective frame. In the second part of the paper two conductor line arrangements are used in order to proof the efficiency of the mitigation technique proposed. The improvement in the field mitigation by the usage of an external capacitance is also made.
Environmental Engineering and Management Journal, 2011
This paper outlines the most recent developments regarding the electric field distribution analys... more This paper outlines the most recent developments regarding the electric field distribution analysis inside very high voltage substations. The study was performed in order to develop and validate a powerful computation tool able to determine and predict the substation zones where the occupational exposure limits exceeds the admissible values imposed by the legislation. The study cases proposed in the paper are taken from the Romanian national power grid but the conclusions and the mitigation ideas outlined can be directly extended to substations belonging to other national or local power grids. In the first part of the paper the principles and methods proposed by the authors for the electric field computation in the vicinity of the power devices composing a very high voltage substation are outlined. The validation of the computation module implemented was done by comparisons with detailed experimental measurements results performed inside a new rehabilitated 400 kV substation. The evaluation of the results outlines a good agreement between the computed and measured electric field values inside the analyzed substation. This fact motivates the usage of the computation module developed in the design of the future high voltage substations in the light of fulfilling the actual regulations regarding the human exposure to power electric fields. In the second part of the paper scenarios to reduce the field values inside the future designed or rehabilitated substations are proposed and examined. The final conclusions end the paper.
Scientific Bulletin, 2015
Technological development put international organisations to effort in order to issue and continu... more Technological development put international organisations to effort in order to issue and continuously reassess standards concerning electromagnetic radiation protection issues. Protection standards have to be continuously reviewed as new data become available. This article provides a brief overview of updates implemented by the latest available protection standards. Currently, standards do not incorporate appropriate safety factors for protection against long-term effects of exposure to electromagnetic fields, thus protection is provided only for the established short term effects of electromagnetic fields on the human body. However, there is still a great deal of questions related to differences in limitations set by international organisations that have issued recommendations for personnel protection against electromagnetic fields.
2015 9th International Symposium on Advanced Topics in Electrical Engineering (ATEE), 2015
Due to the large diversity of devices present in our days, for their better functionality, each a... more Due to the large diversity of devices present in our days, for their better functionality, each and every one of them must be in accordance with the electromagnetic compatibility (EMC) normative. One of the criteria that has to be met by the device is not to produce interferences with other systems, fact studied in this paper. It is known that electromagnetic interferences of a device can appear because of radiated emissions and conducted emissions. This paper will focus on the conducted emissions and will determine them for different devices, at the end also giving a solution for decreasing these emissions.
International Symposium on Electromagnetic Compatibility - EMC EUROPE, 2012
ABSTRACT The paper outlines a recently developed numerical computation algorithm set up for the a... more ABSTRACT The paper outlines a recently developed numerical computation algorithm set up for the analysis of the electromagnetic interferences generated by the overhead high voltage lines (OHL) on the neighbour pipeline networks. The main advantage of the algorithm proposed is that it can handle applications with unparallel arrangements between OHL and pipelines and therefore the induced potential and current values are more accurately computed than the traditional software packages. For this purpose, an original full 3D electromagnetic field model was developed. The computational module is based on a coupled Finite elements (FEM) - Boundary elements (BEM) numerical analysis technique that is detailed in the first part of the paper. The computation accuracy of the numerical algorithm developed was tested considering simple cases and comparing the numerical results with those obtained using a known software package based on the Transmission Lines Method (TLM) and also by analytical solutions. In the second part of the paper an application in the case of a OHL working on normal and fault conditions is outlined. The importance of the magnitude and direction of the currents flowing through the OHL on the induced potentials distribution along the victim pipeline is outlined. The final conclusions end the paper.
Eurocon 2013, 2013
Planar structures are often used in the construction of different equipment due to their many adv... more Planar structures are often used in the construction of different equipment due to their many advantages like reducing the magnetic profiles, lower leakage inductance, lower HF losses in the windings and improving thermal management. One of the greatest disadvantages is the presence of the equivalent parasitic capacitance (EPC) which is also present in our area of interest, EMI filters. In previous researches, the parasitic capacitance was reduced using various methods like increasing the width of the kapton layer, placing an air layer between the windings and shifting the windings. This paper presents the method of EPC cancellation with an embedded ground layer placed so that the electric field energy will be shifted from the unwanted space to ground. The aim of this study, besides eliminating parasitic capacitance, is to maintain the selfcapacitances of the windings as close as possible to their original values. Considering the other studies and their results, two different methods of parasitic capacitance reduction are combined to determine if it is possible to have an even lower EPC. The influence of the embedded ground layer on the whole structure is analyzed, considering the shape, position and thickness of the copper layer and modeling a multitude of structures with varying parameters. The obtained results are compared to ones determined with an energetic parameter method in order to evaluate their accuracy.
2010 Asia-Pacific International Symposium on Electromagnetic Compatibility, 2010
The paper outlines the results of a study regarding the electromagnetic field generated by a 400 ... more The paper outlines the results of a study regarding the electromagnetic field generated by a 400 kV high voltage (HV) substation belonging to the Romanian national Power Grid Company Transelectrica SA. In the first part of the paper, a semi-analytical computation module dedicated to the electric field computation inside substations is presented. Comparison of the computation results with the experimental measurements performed in the substation is outlined. Scenarios to reduce the field value inside substation in order to fulfill the requirements of the actual legislation regarding the occupational exposure to power frequency electromagnetic fields are proposed. The final conclusions of the study performed end the paper.
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Papers by Cǎlin Munteanu