Özgül SALOR-DURNA

Proceedings Paper | 2023 | IEEE Industry Applications Society Annual Meeting

The research work presented in this paper proposes a method for modeling the behavior of the Electric Arc Furnace (EAF) currents for a tap-to-tap time based on the DFT amplitude histograms of the EAF current waves. The method is used to model the EAF current behavior separately for each phase of the EAF operation: boring, melting and refining. The model is verified by comparing the THD histograms and the flicker measurements of the original and modeled EAF current waveforms. The proposed model can be used as an EAF model in the simulation environment for various purposes before the installation of an EAF. The method has low computat . . .ional load compared to various other techniques, since it utilizes only the amplitude distribution parameters of the first 13 frequency components and the one-cycle signal representing the higher order harmonics. The model is novel in the sense that every time the EAF current signal is generated, a unique waveform reflecting the corresponding distributions is generated, which is compatible with the random behavior of the EAF operation. Keyword: EAF current; EAF modeling; electric arc furnace (EAF); power quality; steel makin More less

Rita İSMAİLOVA

Proceedings Paper | 2021 | 2021 IEEE International Conference on Smart Information Systems and Technologies (SIST)

Cybercrime is the offense related to the ethical and legal violation of the computer and IT system, a threat to the security of information systems, and abuse of the Internet platform. It is committed through the Internet or computer systems. Its direct and indirect results disrupt the flow of technological infrastructure. Gaining the knowledge or skills related to the types and content of the cybercrimes is an essential prerequisite in the digital era. Thus, it is very significant to raise the awareness of the younger generation, who will shape the future of societies. In accordance with this, our study aims to identify the cybercr . . .ime awareness of undergraduate and postgraduate students in one of the higher education institutions of Kazakhstan. Totally 133 student participants attended the survey which included questions about the awareness of cybercrime concept and its scope. The findings of the study have revealed that cybercrime awareness of the participants is in moderate-level. Their knowledge and skills need to be improved further. Based upon this, it is very important to teach cybercrime in all levels of education and include it in the educational curriculum Higher cybercrime awareness level of young people will have a positive impact upon their interaction with information systems and tools. They will have better and safer use of Internet and information systems which is quite significant in today's post-modern and post-truth world. This article was prepared within the frame of AP08052656 Readiness assessment of Kazakhstani higher educational institutions for transformation within the context of Triple Helix project, funded by the Ministry of Education and Science of the Republic of Kazakhstan. Keyword: cybercrime; cybercrime awareness; higher education institution; IT (Information Technology) system; Kazakhsta More less

Özgül SALOR-DURNA

Proceedings Paper | 2023 | IEEE Industry Applications Society Annual Meeting

In this paper, utilization strategies for battery energy storage systems (BESS) are assessed in order to reduce the unscheduled power flows in the interconnection lines caused by multiple electric arc furnace operations in Turkey. Turkish electricity network is synchronously connected to the European Network of Transmission System Operators for Electricity (ENTSO-E) via 3 EHV transmission lines. Extensive amount of intermittent loads like electric arc furnaces (EAF) in the electricity network cause unscheduled power deviations at the intertie lines hence Area Control Error (ACE) performance decreases. Therefore, automatic generation . . . control (AGC) operated by the Transmission System Operator (TSO) requires more automatic Frequency Restoration Reserve (aFRR or Secondary Reserves) capacity to counteract the intermittent EAF loads. Nevertheless, the fast nature of EAF loads cannot be followed by the traditional generators participating in aFRR to keep the ACE between required performance limits. In order to mitigate the effects of these highly fluctuating loads on ACE, different AGC models incorporating BESS as secondary reserves in AGC is investigated. Time synchronized measurements collected for 17 major EAFs are used as disturbance to the power system. A two area dynamic simulation model comprising IEEE 14 bus and IEEE 118 bus models with AGC models are used to simulate the ACE variation between ENTSO-E and Turkey. Since batteries will be in high cyclic aging stress due to fast control signals, battery aging performance is also investigated. It is shown that BESS systems are effective in mitigating the unscheduled power flows due to the multiple EAF operations. Keyword: automatic generation controller (AGC); battery energy storage systems(BESS); electric arc furnace (EAF); state of charge (SOC); unscheduled power flows. dynamic simulatio More less

Özgül SALOR-DURNA

Proceedings Paper | 2021 | IEEE Industry Applications Society Annual Meeting

In this research work, deep machine learning based methods together with a novel data augmentation are developed for predicting flicker, voltage dip, harmonics and interharmonics originating from highly time-varying electric arc furnace (EAF) currents and voltage. The aim with the prediction is to counteract both the response time delays and reaction time delays of active power filters (APFs) specifically designed for electric arc furnaces (EAF). Multiple synchronous Reference frame (MSRF) analysis is used to decompose the frequency components of the EAF current and voltage waveforms into dqo components. Then using low pass filters . . .and prediction of the future values of these dqo components, reference signals for APFs are generated. Three different methods have been developed. In two of them, a low pass Butterworth filter is used together with a linear FIR based prediction or long short term memory network (LSTM) for prediction. In the third method, a deep convolutional neural network (CNN) combined with and LSTM network is used to filter and predict at the same time. For a 40 ms prediction horizon, the proposed methods provide 2.06, 0.31, 0.99 prediction errors of the dqo components for the Butterworth and linear prediction, Butterworth and LSTM and CNN with LSTM, respectively. The error of the predicted reconstructed waveforms of flicker, harmonics, and interharmonics resulted in 8.5, 1.90, and 3.2 reconstruction errors for the above-mentioned methods More less

Avıt ASANOV

Proceedings Paper | 2017 | 2017 International Multi-Conference on Engineering, Computer and Information Sciences (SIBIRCON)

In this paper we obtained the formula for the common solution of Riccati equations. Here Riccati equations was solved for common cases. Results obtained have been compared with the conventional ones and a comment has been made on them.

Mehmet KARADENİZ

Proceedings Paper | 2016 | 2016 24th Signal Processing and Communication Application Conference (SIU)

On a power network, events are desired to be monitored to discover their reasons and to take preventive actions. Today, phase measurement units are used to obtain transient data of network, however these devices are expensive and it is not considered as a practical option to place one on each node of the network. Therefore, methods of estimating voltages and currents at non-measured points of the network are required. In this study, a special first-order Kalman Filter is introduced and transients on a power network connected by short lines are estimated using only line parameters. Simulation results show that the method gives satisf . . .actory prediction results despite noisy measurements More less

Mehmet KARADENİZ

Proceedings Paper | 2017 | 2017 4th International Conference on Electrical and Electronic Engineering (ICEEE)

On a power network, events are desired to be monitored to find its reasons and to take preventive action. Today, power quality measurement devices are used to obtain synchronous measurement data of network, however these devices are expensive and it is not considered a practical option to place one on each node of the network. Therefore, methods estimating voltages and currents at non-measured points of the network are required. In this study, a new power system transient state estimation method is designed to estimate transientsin a power network in which some of the loads are unknown. By this method, reduction of measuring devices . . . is aimed considering measurement noises. In addition, the developed method can also be applied on a small area of a power system, and this contributes reducing the amount of measuring devices and calculation time in estimation. The method is applied to a specific region of the IEEE 14 Bus System, and simulation results show that the method gives satisfactory results despite noise More less

Mehmet ERTUĞRUL

Article | 2022 | IEEE Transactions on Antennas and Propagation70 ( 12 )

A broadband, stable, and noniterative free-space method is proposed for dielectric constant ε′r determination of low-loss dielectric slabs from reflection-only measurements through simple calibration standards (reflect and air). It is applicable for dispersive samples and does not require thickness information. Simulations of nondisperive and dispersive samples are performed to validate our method. Dielectric constant measurements of polyethylene and polyoxymethylene samples (9–11 GHz) are carried out to examine the accuracy of our method.

Özgül SALOR-DURNA

Article | 2023 | IEEE Transactions on Industry Applications59 ( 4 )

This paper presents a new waveform correlation based method which determines the individual harmonic voltage contributions of Electric Arc Furnace (EAF) plants supplied from a point of common coupling (PCC). The method is based on the waveform correlation computations between the PCC voltage and the feeder current at the individual harmonic frequency. PCCs supplying multiple EAF plants usually suffer from high voltage harmonic components due to their operation principles. A relationship between the correlation coefficient of the PCC voltage and the feeder current waveforms, and the harmonic voltage contribution of each plant is deri . . .ved and this relationship is used to derive the individual contributions to the PCC voltage. The main idea of the method is based on the fact that harmonic voltage at the PCC is a result of the additive effect of voltage drops on the source side impedance of the power system caused by the individual feeder currents. No real-time impedance measurements are required in the proposed method and no need for the measurements of the other feeders to compute the contribution of a specific feeder in contrast to some previously proposed methods for the same problem. The proposed method is further expanded in order to reveal the effects of the compensation systems of the EAF plants, which identifies the harmonic current sinking problem of a victim plant with a powerful compensation system using further correlation computations between the feeder currents and in-plant current measurements. The proposed method can be easily adapted as a real time harmonic contribution detection tool for the already-installed power quality analyzers, most of which employ synchronized voltage and feeder current waveform measurements. Keyword: electric arc furnace; electrical power quality; harmonic voltage contribution; point of common coupling; power qualit More less

Mehmet ERTUĞRUL

Article | 2022 | IEEE Transactions on Instrumentation and Measurement71

A new deembedding technique is proposed for relative complex permittivity epsilon(r) determination of dielectric materials using gated free-space measurements. Its three main features are 1) it does not require any formal calibration procedure (calibration-free); 2) it is position-insensitive; and 3) it extracts ripple-free epsilon(r) due to gating process. The objective function derived to determine epsilon(r) by the proposed method is validated by free-space measurements of three dielectric samples (polypropylene, polyethylene, and polyoxymethylene). Besides, the accuracy of our method is compared with the accuracy of other calibr . . .ationfree and calibration-dependent methods in the literature More less

Özgül SALOR-DURNA

Article | 2020 | IEEE Transactions on Industry Applications56 ( 3 )

In this article, a new approach to compensate both the response and reaction times of active power filters (APF) for special cases of highly time-varying harmonics and interharmonics of electric arc furnace (EAF) currents is proposed. Instead of using the classical approach of taking a window of past current samples and analyzing the data, future samples of EAF currents are predetected using a deep learning (DL)-based method and then analyzed, which provides the opportunity to make real-time analysis. This can also serve the needs of other possible APF applications. Two different methods for prediction of future samples of harmonics . . . and interharmonics have been proposed: predetection of harmonics and interharmonics in the time domain (TD) and in the frequency domain (FD). To obtain the best possible accuracy for both methods, grid search has been employed for parameter optimization of the DL structure. Both TD and FD approaches have been tested on field data, which had been obtained from transformer substations supplying EAF plants. It is shown that the response time of the APF algorithms can be compensated using the TD-based approach, while it is possible to compensate both the response and reaction times of APFs using the proposed FD-based approach. The developed method can be considered to be a feasible candidate solution for generating reference signals for the controllers of new generation of compensation devices, which can be referred to as predictive APFs More less

Rita İSMAİLOVA

Proceedings Paper | 2022 | IEEE International Conference on Teaching, Assessment and Learning for Engineering (TALE)

The premise behind gamified learning systems is that they improve students’ motivation. However, there is still a scarcity of studies on examining motivational sources that may drive targeted motivation and engagement in gamified learning activities. Improving our understanding of this aspect requires a multi-faceted approach that allows both identifying relevant motivators and assessing their significance. We address this gap by employing three well-recognized theoretical frameworks: Self-determination theory, Expectancy Value theory and Big 5 Personality theory in experimental research aimed to shed new light on the driving forces . . . behind students’ engagement in gamified activities. Accordingly, in this paper we present the results of an empirical study aimed at obtaining evidence on the potential of utilizing these frameworks for predicting learners’ engagement in certain categories of gamified learning activities. A specific objective is to determine which of the three scales yields the highest predictive outcomes with regard to students’ engagement in gamified practicing. The initial results of the study demonstrate empirically that the EVC scale yields the best predictive ability compared to other scales. It also shows the value of using multiple scales for identifying significant sources influencing the engagement in gamified activities. Keyword: gamification; gamified learning; motivation; motivational scale More less