Marko Dimitrijević
@elfak.ni.ac.rs
Department of Electronics
Faculty of Electronic Engineering, University of Niš
RESEARCH, TEACHING, or OTHER INTERESTS
Electrical and Electronic Engineering, Physics and Astronomy, Computer Networks and Communications, Hardware and Architecture
Scopus Publications
Scopus Publications
Marko A. Dimitrijević and Milutin Petronijević
Emerald
Purpose This paper aims to propose a new approach to testing distributed energy resources (DERs) in compliance with the IEEE 1547-2018 standard and describes a new, integrated testing and validation system. Design/methodology/approach The system is built on the virtual instrumentation paradigm, using acquisition modules to measure physical quantities, while signal processing, including intensive calculations of required parameters, data processing, manipulation and reporting are performed on a computing device. Findings Intensive laboratory measurements were performed on a laboratory prototype of a microgrid that emulates DERs. The results obtained using the system described were compared with the measurements obtained by the reference instruments. As all the results match, the usability of the system was verified. Practical implications This approach to the realization of the testing and validation system has obvious advantages compared to the classical instruments and provides significant flexibility in multiple aspects. First, the system described integrates all the functions of different instruments into one measuring system, making the entire testing and validation process significantly cheaper and faster. Second, the implementation of the system is possible on different computing platforms depending on specific needs. Third, the software implementation of the system functions enables simple upgrading and the introduction of new functions or changes to existing ones according to changes in the standard. Finally, the system described is designed to automatically provide reports on compliance with the standard. Originality/value This paper emphasizes the advantages of the proposed approach over classical testing. The value of the paper is reflected in the applicability and practical implications of the proposed and described hardware and software technical solutions.
Milutin P. Petronijevic, Ivana Radonjic, Marko Dimitrijevic, Lana Pantić, and Martin Calasan
Elsevier BV
Marko A. Dimitrijevic, Dejan Stevanovic, and Vanco B. Litovski
Kaunas University of Technology (KTU)
There is no generally accepted definition for apparent power components in circuits with non-sinusoidal conditions. The decomposition of apparent power has been the subject of many discussions and is still an open topic. Over the years, a number of apparent power decompositions have been proposed and analysed, usually in the context of compensation. These analyses were performed by means of simulations or by calculating quantities using measurements on a simple test circuit. Here, we present a unique system capable of simultaneous apparent power decompositions for non-sinusoidal conditions in real-time. The system can calculate power components related to various power decompositions. The system’s capabilities are demonstrated on non-linear load characterization.
Dejan Stevanovic, Miona Andrejevic Stosovic, and Marko Dimitrijevic
IEEE
Existing system for registration of electric energy consumption is based on the application of commercial power meters and/or measuring groups at each load/consumer. National standards stipulate that the power meters register active, and measuring groups register both active and reactive energy. These requirements give a correct picture of consumption in systems where linear loads dominate. Unfortunately, the needs of electric energy consumers have significantly changed in recent years, so the number of nonlinear loads has increased remarkably. Non--registration of distortion component of power causes losses in power system that are proportional to power and number of nonlinear loads. Measurement results of the consumption of different types of modern loads have confirmed our presumptions. Modification of built-in power meters and measuring groups is proposed, so that it easily fits into the existing system.
Nenad N. Cvetkovic, Marko A. Dimitrijevic, Dejan B. Jovanovic, Dragana U. Zivaljevic, and Dragan D. Krasic
Kaunas University of Technology (KTU)
The topic of the research presented in this paper is numerical calculation and analysis of the electric field and Specific Absorption Rate (SAR) distributions in the vicinity of dental amalgam exposed to the radiation of mobile phone at the frequencies corresponding to 3G and 4G mobile networks. This is carried out by numerical solving of the electromagnetic propagation equation. The results related to different tissues and organs placed in the vicinity of dental amalgam and exposed to radiation are presented and analysed. In order to obtain the most accurate results, the realistic 3D model of human jaw has been created. A comparative analysis of models with and without dental amalgam has been carried out, with aim to determine the impact of amalgam on biological tissues in its vicinity. According to the obtained results, the maximum values of electric field strength and SAR are higher in the presence of dental amalgam. In both cases, maximum values are out of bounds of safety limits.
Marko Dimitrijević, M. Andrejević Stošović, and V. B. Litovski
Informa UK Limited
ABSTRACT Designing an efficient photovoltaic (PV) system is a complex task that involves modelling and simulation of all of its subsystems. The simulation results are usually obtained by performing behavioural simulations, which is useful when simulating at the system level, though it is not possible to implement models of real electronic components due to an absence of adequate libraries. In this manuscript we will focus on a simulation of electronic circuits performing maximum power point tracking control (MPPT), which is one of the standalone PV subsystems, using circuit-level model. Here we will introduce some modifications to perturb and observe method in order to facilitate circuit-level simulation, and present a SPICE circuit implementing that MPPT algorithm. The importance of the contribution comes from the fact that the SPICE implementation of the algorithm is circuit (technology) independent.
Dragoljub D. Dimitrijevic, Marko A. Dimitrijevic, Goran S. Djordjevic, and Milan Milosevic
Author(s)
In this paper we discuss tachyon scalar field with constraints in the cosmological context. The tachyon field is described by a Dirac-Born-Infeld (DBI) type action. In order to quantize the system using path integral method we propose extension of the system introducing an auxiliary field in the minisuperspace framework.In this paper we discuss tachyon scalar field with constraints in the cosmological context. The tachyon field is described by a Dirac-Born-Infeld (DBI) type action. In order to quantize the system using path integral method we propose extension of the system introducing an auxiliary field in the minisuperspace framework.
M. Andrejevic Stosovic, D. Stevanovic, and M. Dimitrijevic
IEEE
In this paper we used artificial neural networks for classification of nonlinear loads. The special attention is payed to this kind of loads since they are the most difficult to register using existing monitoring methods. Carefully chosen parameters are first measured and calculated, and these values are then used as a training set for a neural network. We also considered situations when different processes are run on a PC, and we showed that this does not influence our method, since it works properly in these situations also.
Miona Andrejevic Stosovic, Dejan Stevanovic, and Marko Dimitrijevic
IEEE
In this paper artificial neural networks are used for identification of nonlinear loads on the network, as one of the methods for non-intrusive load monitoring. Specific parameters of a group of the nonlinear loads are first measured, and then a neural network is used in order to identify which load, or group of loads, is active on the network. It is shown within an example that the task of loads identification can be done successfully.
Marko Dimitrijevic, Dejan Stevanovic, Miona Andrejevic Stosovic, Milutin Petronijevic, and Predrag Petkovic
IEEE
In this proceeding we present basic steps for design a system for harmonic and reactive power compensation in smart grid, using photovoltaic (PV) system. First, methods for harmonic monitoring and measurement will be elaborated. Next, we will discuss harmonic reduction techniques that are usually used. The system for harmonic compensation based on photovoltaic energy generation that provides the functions of a power quality conditioner will be proposed. We will also address the issue of proper quantity for harmonic compensation contribution measurement at power grid.
Slobodan Bojanic, Srdan Dordevic, Marko Dimitrijevic, Lidija Korunovic, and Dejan Stevanovic
IEEE
The work contributes to the identification of small nonlinear appliances which are hardly distinguished by existing noninvasive load monitoring methods. It improves the steady load monitoring by introducing distortion power as an additional parameter to the widely used Hart's algorithm based on measurement of active and reactive power. The results show that the method efficiently distinguishes the variety of nonlinear appliances whose usage is fast growing nowadays. Furthermore, this approach is advantageous in comparison with other approaches, which use three parameters to precisely identify the appliances, due to its simplicity. Namely, distortion power can be easily determined using only smart meters and thus no any additional measuring equipment is required.
Miona Andrejević Stošović, Ivan Litovski, Duško Lukač, Marko Dimitrijević, and Vančo Litovski
SAGE Publications
Starting with the experience that the output voltage and the output current of a photovoltaic panel are not pure direct current constants due to the inevitable connection to a converter (or inverter) that is working as a switching system, we came to the conclusion that interest exists for the behavior of the solar cell at the frequencies of the harmonics of the converter’s switching frequency, which is subject to change according to the maximum power-point tracking. In other words, a need exists for frequency domain characterization of the solar cell, for which a linear small-signal model is necessary. To enable simulation for small signals, development of a linear reactive model was considered. Since a one-diode large-signal model already exists, it was used as a basis for the extraction of the parameters of the small-signal model. The new model was represented in the form of a parallel RC two-terminal circuit, the R and C being functions of the photocurrent (acting as a map of the illumination) and the diode voltage. Since the R and C of the model are quiescent-point dependent, their values as a function of the illumination and the diode voltages were approximated by artificial neural networks (ANNs). Separate ANNs were created for modeling R and C. To verify the model, two small-signal simulations were performed. The first one was done with the existing nonlinear model, while the second was done with the new linear model (running the ANNs). Excellent agreement was obtained.
Miona Andrejević Stošović, Marko Dimitrijević, and Vančo Litovski
Informa UK Limited
The usual way of creating a cyber attack is through implementation of malware via the Internet. Among many types of malware, of special interest are those that enable eavesdropping on the activities within the computer, making it possible to define the software on which the computer is running. An adversary can benefit from this information in a way that is convenient for him or her. Here, we expose a new, entirely different way of eavesdropping and of monitoring the activities within the computer. It is based on measurement of the supply current taken from the electricity distribution grid. Because the computer, as many other electronic loads, is a nonlinear one, abundance of harmonics can be found in that current. Our discovery is the fact that the harmonic content is dependent on the type of activity within the computer, so, by proper analysis of the current waveform, one may recognize what is going on in it. We propose an artificial neural network-based method that unambiguously recognizes which software is running. We also propose a proper measurement procedure based on the technology we described in our earlier articles.
Zargaryan Y. Grigor, Aharonyan K. Vahram, Melikyan V. Nazeli, and Marko A. Dimitrijević
Faculty of Electrical Engineering, University of Banja Luka
This paper describes a new verification environment for USB 2.0 controller. New methodology is presented, where a co-simulation environment is used as one of the starting points for the embedded hardware/software development and as an accelerator of the overall design process. The verification environment is based on the device emulation/virtualization technique, using USB controller's real register transfer level (RTL) instead of models. This approach is functionally very close to the corresponding real-world devices and allows wider opportunities for hardware debugging. The new software utilities for USB host and device functionality testing are also presented. This tool allows generating custom tests by including various transfer types and modifying parameters such as data payload, interval, number of pipes, etc. It can be used for both hardware (HW) and software (SW) limitations characterization, as well as debugging.
Miona Andrejević Stošović,, Marko Dimitrijević, Duško Lukač, and Vančo Litovski
Faculty of Electrical Engineering, University of Banja Luka
One among several equally important subsystems of a standalone photovoltaic (PV) system is the circuit for maximum power point tracking (MPPT). There are several algorithms that may be used for it. In this paper we choose such an algorithm based on the maximum simplicity criteria. Then we make some small modifications to it in order to make it more robust. We synthesize a circuit built out of elements from the list of elements recognized by SPICE. The inputs are the voltage and the current at the PV panel to DC-DC converter interface. Its task is to generate a pulse width modulated pulse train whose duty ratio is defined to keep the input impedance of the DC-DC converter at the optimal value.
Miona Andrejevic Stosovic, Marko Dimitrijevic, and Vanco Litovski
IEEE
Circuit for maximum power point tracking (MPPT) is one among several equally important subsystems of a standalone photovoltaic (PV) system. In this paper we will implement one algorithm for maximum power point tracking, based on the maximum simplicity criteria, into the whole PV system. SPICE circuit simulation of the complete standalone PV system will be performed in order to verify the proposed algorithm. Different working conditions will be examined.
Marko Dimitrijević, Jelena Milojković, Slobodan Bojanić, Octavio Nieto Taladriz, and Vančo Litovski
Inderscience Publishers
An attempt is made in this paper to summarise the state of the art in the interaction between the Information Communication Technologies (ICT) that becomes ubiquitous and the electrical power production and distribution. Both are considered to have a difficult task to fulfil enormous rise of demand that is becoming above all expectations. In the same time they technologically interfere in the sense that they mutually help in the fulfilment of their main task while in the same time loading each other with problems inherent to the respective technology. In the paper, we will try to merge our (LEDA laboratory of the University of Ni) own results with ones available in the literature in order to give as complete a picture of the subject as possible.
M. Dimitrijevic, J. Milojkovic, S. Bojanic, and V. Litovski
IEEE
An attempt is made in this paper to summarize the state of the art in the interaction between the ICT (information communication technologies) that becomes ubiquitous and the electrical power production and distribution. Both are considered to have a difficult task to fulfill enormous rise of demand that is becoming above all expectations. In the same time they technologically interfere in the sense that they mutually help in the fulfillment of their main task while in the same time loading each other with problems inherent to the respective technology. In the paper we will try to merge our (LEDA laboratory of the University of Niš) own results with ones available in the literature in order to give as complete a picture of the subject as possible.
MARKO A. DIMITRIJEVIĆ and VANČO B. LITOVSKI
World Scientific Pub Co Pte Lt
Power factor and distortion measuring usually require dedicated and expensive equipments. Computer-based acquisition modules and software provide for a possibility to create simple and nonexpensive methods and instruments for power factor measurement and distortion characterization of small loads and bring all advantages of virtual instrumentation. A new approach to power quality characterization by measuring power factor, distortion, and several other parameters of small electric loads (up to 0.5 kW) will be described in this paper. Besides low price maximum versatility and adaptability are provided without any loss in accuracy.
M.A. Dimitrijevic and V.B. Litovski
IEEE
Computer integrated laboratory for analogue electronics was developed. This paper presents analysis of specific linear electronic circuits, such as differential amplifier, oscillator, operational amplifier, power amplifier, full-wave rectifier and stabilizer with series transistor. All analysis are performed using virtual instruments implemented using personal computer acquisition card and LABVIEW development software