Carpathian Journal of Electrical Engineering

35-45

Authors: Vlad Mihai PANAINTE, Horia BĂLAN

Vibration artefacts that appear at small dimension components are frequently encountered in multiple domains such electronic equipment production, surgical and high precision medical applications, optical applications high quality photo/video equipment. The main objective of this work is to develop a reduced model that accurately represents the dynamics of a small dimension titanium plate and define a suitable vibration control system. With the aid of powerful engineering software instruments, the mathematical model of the studied object is defined with MATLAB after it was modeled and analyzed with ANSYS (mode shape analysis). The mathematical model is developed based on the eigenvectors and eigenvalues extracted from ANSYS and it is called the state space model which is than transformed into a transfer function for simplicity reasons. The mathematical model is than integrated in Simulink and the vibration velocity is evaluated, followed by the definition of a control system comprised of a piezoelectric actuator and PID controller. The evaluation of the system was performed by applying a step signal at the input of the plant and the velocity response is observed comparatively in three configurations as listed: small dimension plate response, plate and piezoelectric actuator and full plant (titanium plate, actuator and PID controller).

62-74

Authors: Nicholas Kwesi PRAH II, Emmanuel Assuming FRIMPONG, Elvis TWUMASI,

An algorithm that modifies the individual experience of mayflies in the mayfly algorithm (MA) to enhance its performance, is proposed. The proposed algorithm called the Modified Individual Experience Mayfly Algorithm (MIE-MA) calculates the experience of a mayfly by finding an average of the positions the mayfly has been to instead of just using the best position. A chaotic decreasing gravity coefficient is also employed to enhance the balance between the exploitation and exploration of the algorithm. The proposed algorithm was compared to the original MA, and two recent variants named, PGB-IMA and ModMA, on eight benchmark functions. The parameters used for comparison were Mean Absolute Error, Standard Deviation, and convergence rate. The results validate the superior performance of the MIE-MA over the other three algorithms. The MIE-MA yields better optimal values with minimal iterations.

92-105

Authors: Mihaela ȘTEȚ, Bogdan CIORUȚA

In the last decades, there was identified evidence of climate change. These climate changes are associated with various effects on different types of ecosystems and with changes in mountain ecosystems. To respond to these challenges, some states have started the implementation of general and specific measures, among them being the measures taken within the energy sectors.

127-138

Authors: Olivian CHIVER, Liviu NEAMT, Mircea HORGOS

The main paper’s purpose is to present how students and researchers can use the ADVISOR software in the design and simulation of electric vehicles. Not only electric vehicles but also hybrid, fuel-cell, or internal combustion engine vehicles can be simulated, this paper refers only to the former. Starting with the principal electric vehicle components such as the energy storage system and the electric motor, the user can choose them from the existing ones in the library or can compose/define new others. The software allows imposing different driving cycles (choosing from the library or user-defined) and calculates selected performances of the vehicle based on the simulation. Should emphasize the eloquent way of ADVISOR in presenting the results on the energy consumption of the main components as well as of the entire vehicle. Thus, it is easy to find how certain equipment affects the overall efficiency of the electric vehicle.

157-163

Authors: Vitalii PANCHUK, Cristian BARZ, Volodymyr KOPEI, Oleh ONYSKO,Iuliia MEDVID,Anatolii PANCHUK, Tetiana LUKAN

Modern technical universities are obliged to show flexibility in the provision of educational services, since the modernization of modern enterprises is ongoing and professional employment additionally requires the rhythmic improvement of skills, skills and educational level of the employee, the permanent acquisition of other additional knowledge and skills that increase the value of the employee in the event of a corresponding need for them applying, as well as obtaining, another profession, if the employee foresees the application of his knowledge at the intersection of different fields of activity. And all this requires enabling the optimization of the provision of educational services by unifying their certain components in order to save its time and financial resources.

174-184

Authors: Iryna SMYK, Liudmyla ARKHYPOVA

The article presents an analysis of electricity use in the tourism sector of Ivano-Frankivsk region. The territorial structure of electricity consumption distribution in the tourism sector across the regions of Ivano-Frankivsk region has been studied, and quantitative indicators of electricity use by the tourism sector over the last five years have been modeled. It has been demonstrated that as the number of tourists increases, the proportion of electricity consumed from the overall energy network also increases, as the share of electricity generated from renewable sources for self-sufficiency of the tourism sector is currently negligible. Analysis of global experience allows us to assert that the use of renewable energy sources is environmentally friendly, modern, safe, and resource-efficient, and is the path chosen by all developed countries. A review of information sources suggests that modern tourism development includes several aspects: reducing carbon footprint, reducing the impact on local ecosystems, and increasing economic benefits for local communities. It is important to understand that expenditures on ecology and nature conservation measures are not just unavoidable costs, but also investments in business. Such an attitude allows for benefits and profits. Investments in green technologies always pay off, as today’s modern tourists are willing to pay for comfort and ecology. The necessity of referring to global experience in using renewable energy sources in tourism is emphasized, and trends in implementing global experience in the practice of tourism industry in Ivano-Frankivsk region are analyzed.

194-207

Authors: Zoltan ERDEI, Cristian BARZ, Alexandru GRIB, Cristina TAMASAN

This paper aims to identify, analyze, and conclude on solutions to improve the energy performance of an economic agent, by carrying out an energy audit to satisfy part of the energy needs of the organization. The respective economic agent operates in the field of the production of devices for the control and distribution of electricity. The objectives of the paper refer to the identification of the way of using electricity, to the identification and analysis of alternative solutions, such as photovoltaic panels, which could substantially reduce energy costs, to the performance of an economic analysis regarding these alternative solutions to determine which are economically efficient for the economic agent in question. The site energy audit was carried out during the week commencing 10th February 2023 and consisted of a health and safety site induction, followed by a kick-off meeting with key site personnel, followed by data gathering and surveys of the factory operation and processes. The objective of the energy survey is to provide a compliant audit for the ESOS submission for the organisation. The energy audit covers all energy consumption applicable to the site in order to establish an energy use map for the major consumers and identify potential energy saving opportunities.The energy savings identified in this study are based on the findings of the site visits and are considered viable opportunities that will require further work to develop them into investment grade business cases.

28-44

Authors: Abdelouahab ZAATRI

The well-known AM2 model is commonly used for simulation of biotechnological processes of two-phases anaerobic digestions. Nevertheless, numerical simulation and graphical results usually obtained by solving the non-linear system of differential equations characterizing this model do not always enable an easy analysis of the processes as well their sensitivity to the variations of the different parameters and the initial conditions. In this paper, as an alternative to simulation, an analytical approach is proposed for batch reactors. It consists of adopting some approximations to reduce the mathematical complexity of the coupled differential equations of the AM2 model. The aim is to derive approximate analytical expressions concerning the dynamical evolution of the substrates and bacterias involved in reactions. The obtained expressions, therefore, permit a relatively easy analysis of the evolution of the main processes and their sensitivity to the different parameters and initial conditions. Moreover, it provides an explicit mathematical expression that enables to estimate the cummulative production of methane. The comparison of the obtained results by this proposed analytical approach to the numerical simulation of the AM2 model shows a satisfying qualitative convergence of the proposed approach to the AM2 model.

58-70

Authors: Md Murshadul HOQUE, Mithun CHAKRABORTY, Joy RUDRA, Md Arif Iftekhar MAHMOOD

This paper proposes a smart home appliance scheduling management (HASM) system based on demand response. An IoT based HASM system is developed to provide an efficient electricity consumption scheme to residential consumers for scheduling their appliances in a cost-effective way and smartly throughout a day. This smart load scheduler takes residential electricity users’ preferences to shift the appliances with deferrable characteristics at cost effective periods considering the user is aware of dynamic tariff information. The user interaction to the scheduling of loads provides maximum comfort level as well as saving of total electricity bill, and the effective utilization of demand response strategies to reduce peak hour electricity consumption. The results of this development indicate a reduction of daily energy consumption confirming the consumer comfort.

81-93

Authors: Mihaela GRIB, Ionela VLAD, Ovidiu Dorin LĂUDATU, Alexandru Radu GRIB, Mihai IORDACHE

The main objective of this paper is to correctly define the hybrid equivalent circuits. These circuits allow the separation of the linear portions of electronic circuits from the nonlinear ones and in this way the polarization process of electronic devices becomes much more efficient. When linear and/or nonlinear analyzed circuits have a small number of nonlinear circuit elements, their analysis, synthesis, and simulation are performed more efficiently if the nonlinear part of circuit is separated from the linear one. A new modeling technique, called H ~ modeling, is introduced for multi-port networks. It is shown that H ~ models are more dynamic compared to equivalent Thevenin or Norton circuits and have the ability to describe port behavior more accurately. A special type of model H ~ is also introduced, called model H ~ nullified, or simply model H ~ and many properties of H modeling are investigated, including circuit energy management. It is shown that the H models are not limited to single-port networks, but also cover multiport. A major property of H modeling is the local polarization of transistors. It separates the nonlinear components from the linear portion of circuit for faster and more efficient polarization of circuit. Here a designer can take advantage of H-modeling and bias individual transistors (or in combinations) with no need to perform the normal circuit biasing. The proposed strategy separates linear and nonlinear portions of an analog circuit and takes more control of nonlinear portions. This separation of portions (components) of circuit is achieved by introducing a new port model that cancels the ports of nonlinear devices. In turn, this leads to a new technique for polarizing nonlinear components. This separation of portions (components) within the circuit is accomplished by introducing a new port modeling that nullifies the ports of nonlinear devices.

113-120

Authors: Cristian BARZ, Zoltan ERDEI, Oleh ONYSKO, Paul TAMAS, Andreea POP, Teodora UNGUREANU

To control and reduce energy consumption, it demands to install a network of sensors and using a dashboard to monitoring data acquisition from its. Energy monitoring is necessary to keep track of energy consumption according to the season, weather conditions and the flow of use of electrical appliances in the institution. The paper presents an approach for monitoring energy efficiency base on Arduino modules (smart-MAC) through a dashboard application. Dashboard WEB application has the advantage of leting the user a flexible indicator and chart widgets configuration for create an unlimited number of boards and devices connected to the same account. To realize an efficiency use of energy in public institution the date is analyze and on results can be take measurements for it.

131-139

Authors: Irina SMICAL

Integrated circuit boards are component of most Waste Electrical and Electronic Equipment (WEEE). These are generated worldwide at an alert rhythm and their recycling is done to a small extent (about 20%). The paper presents an experimental simulation of the presence of printed circuit board waste (PCBs), from end-of-life computers, in three aquatic environments with different pH (pH 4.00, pH 5.63 and pH 8.00). After stagnation for 17 weeks, values of the concentrations of heavy metals released by the PCBs in the solutions were obtained. These indicated that the presence of these boards in aquatic media may impair water quality by inducing moderate risks for surface water and lower risks for groundwater bodies. Heavy metals such as copper and lead, especially in acidic and neutral environments, fell into the worst quality class for surface water and exceeding of the maximum allowable value for the reference groundwater body (ROSO12) were recorded for copper in the acid and neutral initial solutions.

150-158

Authors: Luminița TODEA, Anamaria FĂLĂUȘ, Ramona DEMARCSEK

The employability of graduates has become an issue that countries around the world have imposed on their national higher education systems to varying extents. Acquiring effective employability skills becomes increasingly important for both employers and employees in the field of engineering. Employers generally see a graduate’s achievements related to the subject discipline as necessary but not sufficient for them to be recruited. Achievements outside the boundaries of the discipline, the so-called soft skills, are generally considered to be relevant in the recruitment of graduates. A certain level of awareness among engineering undergraduates should be addressed regarding lacking or mismatching specific soft skills required in their potential workplace context. Therefore, the purpose of the article is to identify and discuss engineering students’ perception on the importance of employability skills such as: communication skills, problem solving and interpersonal skills so that they should overcome problems in getting suitable jobs in the future.

166-172

Authors: Bogdan-Vasile CIORUȚA, Mihaela ȘTEȚ, Mirela COMAN

The construction and commissioning of micro-hydropower plants is a solution for obtaining cheap electricity, but it also has a not negligible impact on the environment. Romania, like any of the member states of the European Union, has committed itself to a share of energy, in the sense of obtaining electricity in the most environmentally friendly way possible. Micro-hydropower plants also fall into this category. From our point of view, their construction started with too much exuberance because we not only have some European rules that we must obey about the green energy quota, but we also have some European rules provided by directives that refer to the protection of ecosystems. And then we must judge a balance between getting the share of green energy we are committed to, but at the same time protecting our ecosystem. We have synthesized, reported, and analyzed the impact of micro hydropower plants according to good practice guidelines aimed at the harmonious development of communities about nature.

188-193

Authors: Marius COSMA, Dinu DARABĂ, Norbert GAȘPAR

The paper presents the optimization of the control process of a family of complex aircraft parts by designing a modular device for the CMM (coordinate measuring machine), how to assemble the elements, how to align the device on the machine table and the presentation of real advantages and disadvantages regarding the designed device.

203-212

Authors: Mirko SAJIĆ, Dušanka BUNDALO, Željko VIDOVIĆ, Zlatko BUNDALO, Dejan LALIĆ, Luka SAJIĆ

The paper considers, proposes and describes the possibilities and ways of transforming teller/counter services using modern and mobile information technologies in order to increase the efficiency of such business. The shortcomings of the traditional teller/counter services are pointed out, and the reasons that will lead to the transition to a modern automated way of providing teller/counter services, without the physical presence of a person, are presented. Then, various variants of partial or complete automation of teller/counter services using modern mobile information technologies are considered. The impact of the pandemic on accelerating the online working and services is mentioned. Then, ways of transforming teller/counter business are proposed and described, through several variants, such as the use of intelligent digital teller/counter terminals and the application of remote online services, through several practical examples. Factors that influence the limitation of the degree of automation and what needs to be done to overcome these limitations are highlighted. Groups of users are profiled who, according to their objective and subjective reasons, will use certain types of automation of teller/counter operations. Appropriate intelligent multifunctional devices are presented, which are already used in some areas as a transitional solution in the automation of the provision of teller/counter services.

227-235

Authors: Adina POP-VĂDEAN

An intelligently developed society is defined by a concept that integrates information technology in all its fields in which man is the direct beneficiary of this environmentally friendly process. Man is both the main actor and the direct beneficiary of the products and services of the intelligent society. This detail must be the determining factor for the development of any society from a classical to a smart one and here comes the concept of Human Informational Field (HIF) accompanies the human being in his interactions. But smart society is about connecting between people, systems, about sharing information and so we get to the Internet of things, or IoT a system of interrelated computing devices, mechanical and digital machines, objects, animals or people. The internet of things helps people live and work smarter, as well as gain complete control over their lives. Because IoT is a sensor network of billions of smart devices the problem of energy supply appears. Energy recovery or harvesting systems is a possible solution that could enable IoT nodes to scavenge self-sustaining energy from environmental sources. In this article we will review these systems and emphasize their importance in the development of smart society or smart city.

252-261

Authors: Marina Daniela SAS

The paper presents a theoretical study and a practical realization of a system for access based on the imprint of a room and keeping track of people who are unauthorized. The assembly is done on a small scale (at the model level). For the practical realization we used the FPM10A fingerprint reader module, the Arduino AT Mega 2560 control unit equipped with the AT mega2560 microprocessor and an ESP32Cam camera equipped with the ESP32 microprocessor. The role of the fingerprint reader will be to check and recognize the fingerprints already stored in his memory, to the people who will want you to enter the rooms. The role of the camera will be to take a picture of the person whose fingerprint is not recognized. To view the allowed or not allowed access status, we mounted the 1.8” TFT LCD display. For the power supply of the assembly I used a 12V source that supplied my electromagnetic lock and from this source with the help of a low voltage converter you could power your Arduino board and ESP32Cam board, these being necessarily supplied at 5V voltage. The advantage of this application is that it secures the entrance to a room and can keep track of remote unauthorized persons who have tried to enter the room.

277-282

Authors: Paul TAMAS, Andreea POP

In this paper we talk about the user’s movement in virtual reality. The programmable part of the application is made in the C ++ programming language, and as the engine for running the graphic image we used Unreal Engine developed by Epic Games. Fragments of code appear in the paper for the calculation and positioning of the user in space, on a two-dimensional plane. The work also contains instructions to be able to make the settings so that the application can be controlled by the glasses levers. The whole project is developed for HTC VIVE PRO virtual reality smart glasses.

18-33

Authors: Andreja SAMČOVIĆ

This paper describes in detail analysis of Digital Cinema Package (DCP) file format structure, which is today widely used for distribution of digital movies for digital cinema. The whole process from creating source files, following by intermediate steps, to the final form of this format, is presented as well. Security principles are covered by Key Delivery Message (KDM). Some free software for creation DCP are mentioned at the end of this paper.

42-56

Authors: Emmanuel Asuming FRIMPONG, Philip Yaw OKYERE, Johnson ASUMADU

This paper presents a method based on wavelet analysis (WA) and Multilayer perceptron neural network (MLPNN) to predict transient stability status (TSS) after a disturbance. It uses as input data, generator terminal frequency deviations extracted at a rate of thirty-two samples per cycle. Only the first eight frequency deviation samples per machine are needed. The eight samples are sub-divided into two sets, one set consisting of the first four samples and the other set consisting of the last four samples. Each set of samples is decomposed into 2 levels using the Daubechies 8 mother wavelet and the absolute peak value of detail coefficients obtained. The absolute peaks of detail coefficients of the first sample sets of all generators are added and so are the absolute peaks of detail coefficients of the second sample sets. The two summed values are then used as inputs to a trained MLPNN which predicts the TSS. The method was evaluated using dynamic simulations carried out on the New England test system. The method was found to be accurate and can be implemented in real-world systems to provide system operators advance information on system stability, following disturbances, to aid the deployment of needed emergency control measures.

73-85

Authors: Irina SMICAL, Mariia ORFANOVA

This paper addresses a number of issues regarding the management of waste electrical and electronic equipment (WEEE) and its influence on environmental and human health factors. The study was conducted for Maramures County to highlight the WEEE management and its threats to the environment and human health. Worldwide research results show that improper WEEE treatment and recycling is a factor of environmental pollution and the generation of various diseases, especially where rudimentary techniques are used and there is no means of protecting workers. By dismantling mechanical and pyrometallurgical processing of WEEE components result in a series of contaminants that can pollute the soil, surface water, groundwater, the atmosphere and finally can cause a lot of human diseases. Following the investigations, it is found that the management of WEEE in Maramureș County poses a low risk of contamination given the fact that in this county only WEEE collection is made not also their treatment or recycling. Moreover, all collection activities of WEEE are made safe and are authorized by the environmental protection point of view.

96-104

Authors: Radu JOIAN, Claudiu LUNG, Mircea HORGOȘ

The paper focuses on the use of the Homer software on an autonomous hybrid system. The dedicated Homer software is intended for the energy management analysis of renewable electricity sources. The program simulates the operation of the systems, performing calculations on energy variations for each of the 8760 hours (specific to one year).

17-29

Authors: Francis EFFAH, Philip OKYERE, Patrick WHEELER, Alan WATSON , Jon CLARE

An optimized space vector modulation technique for controlling a quasi Z-source NPC inverter for solar photovoltaic application is presented in this paper. The presented algorithm optimizes the number of switching transitions over a switching cycle by modifying the placement of the shoot-through states in some of the sub-triangles of the space vector diagram of a conventional neutral point clamped inverter. This approach leads to a reduction in the total losses of the quasi Z-source inverter by reducing the switching losses. The presented concepts are expected to be cheaper than existing methods because a reduction in losses will lead to the use of smaller and cheaper heat sinks in practical implementation. In this paper, the effectiveness of the proposed optimized space vector modulation technique has been demonstrated through simulations in SABER®.

45-60

Authors: Amina GABOUR, Samia BENZAHIOUL, Abbderrezak METATLA, Toufik SEBBAGH

The aim of this paper is to design the sizing and optimization of multi-source system PV/Diesel/Battery, whereat the power management algorithm is applied to feed load in Algeria where the GA method is used to find the best configuration of the system and for sizing purpose of the components, based on the minimum total cost of the system (STC) subject to renewable energy fraction (FR).Thus, the results show the impact of RF on the STC in addition to the choice of the best configuration and the most adequate one.

77-92

Authors: Mihaela STET

Identification of risks and potential effects of exposure to electromagnetic fields has aroused the interest of researchers in various fields to reduce or even eliminate them. However, the problems they raise, also, determined the need to regulate the exposure limits, thus establishing a series of regulations at the level of different states, of some national and international standards. The paper presents a comparative analysis of several national and international regulations regarding the exposure limits for the general public and for different working environments.

22-38

Authors: Emmanuel Asuming FRIMPONG, Philip Yaw OKYERE, Johnson ASUMADU

This paper presents a simple and effective technique for real-time prediction of transient stability status following a large disturbance and compares the performance of three artificial intelligence (AI) techniques commonly employed as decision making tools. The (AI) techniques compared are support vector machine (SVM), multilayer perceptron neural network (MLPNN), and radial basis function neural network (RBFNN). The stability status prediction scheme samples rotor angles of all system generators and extracts the absolute value of the first sampled rotor angle value of each generator. The extracted absolute rotor angle value of all generators are summed and fed as input to a decision tool. The scheme was tested using simulations carried out on the IEEE 39-bus test system. One hundred percent prediction accuracy was obtained when SVM and MLPNN were each employed as decision tools. The use of the RBFNN as decision tool resulted in only sixty-three percent prediction accuracy.

53-68

Authors: Giovanni LUCCA

This paper deals with the evaluation of the inductive coupling between an overhead finite length wire circuit and a buried wire circuit, both with earth return, in the range of Extremely Low Frequencies (ELF). In particular, the attention is focused on the key parameter for this kind of problems i.e. the per unit length (p.u.l.) mutual impedance between the two circuits. Starting from the exact formula involving a Sommerfeld’s integral, two new approximated analytical formulas, having different levels of approximation, are derived; the advantage of these formulas is that, in such a way, the p.u.l. mutual impedance is expressed only by means of elementary functions so avoiding numerical calculations of the Sommerfeld’s integral. Finally, a comparison between the two proposed formulas is made.

87-98

Authors: Toufik SEBBAGH, Ridha KELAIAIA, Assia ABDELOUAHED, Abdelouahab ZAATRI

This paper assesses the optimal farmland that can be irrigated by a predetermined renewable energy system. The optimal irrigated surface from an agriculture area, cultivated by potatoes and tomatoes and powered by a PV system is studied. Two scenarios are discussed: the constraints applied to the first scenario is the limited surface of the agricultural area. While in the second scenario, the surface cultivated with tomatoes must be at least ¼ the surface cultivated with potatoes. Linear programming based on the Simplex algorithm is used to solve the optimization problem. The obtained results show that for the specified cultivating area, and for 10 panels at hand, an optimal surface of about 5.6 ha and 4.7 ha for the first scenario and the second scenario, respectively can be satisfied.

114-123

Authors: Abdelkrim MOSTEFAI, Hamza ABID, Smail BERRAH

The miniaturization of MOS transistors has increased the integration density and speed of operation of the circuits. This miniaturization has led to parasitic phenomena that degrade the current-voltage characteristics. The EKV MOSFET Model resolves this problem, this component enables to progress in miniaturization. This paper presents a simulation of MOSFET ‘EKV model’ using Matlab to identify the different output and transfer characteristics, transconductance gm, Methodology gm/ID, etc.