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

Elmira ABDILDAYEVA

Proceedings Paper | 2024 | AIP Conference Proceedings3085 ( 1 )

The paper investigates the solvability of a boundary value problem in the control of an oscillatory process described by control in partial derivatives of the first order. It has been established that there are an infinite set of controls, as solutions to the system of nonlinear Fredholm integral equations of the first kind, each of which transfers the controlled process from the initial state to the final specified state in a specified time. Sufficient conditions for the existence of a nonlinear optimization solution are found.

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

Asılbek ÇEKEEV

Proceedings Paper | 2019 | Topology and its Applications252

The various types of ultrafilter-completeness on zero-sets of uniformly continuous functions are introduced, their properties are studied and characterizations in the category are given.

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

Zeki SEVEROĞLU

Proceedings Paper | 2013 | Proceedings of the International Conference on Environmental Science and Technology

When evaluating the negative impacts of heavy metals in the environment, plants can be used as biological indicators in assessing damage done by bio-accumulation of heavy metals. For detecting the genotoxic effects of heavy metals, the RAPD-PCR technique is applied in plants. In this study, Blyophyllum daigremontianum was used as a bio-indicator for Cadmium (Cd) pollution. B. daigremontianum plantlets were obtained from bulbiliferous spurs. They were grown singly in standard pots and each of the experimental groups of 5 replicates were watered daily with Hoagland solution (20 ml) containing 0, 50, 100, 200 and 400 mu M Cd for two mo . . .nths. Plantlets were harvested at the end of the two-month experimental period and photosynthetic pigment (chlorophyll a, chlorophyll b, total chlorophyll, chlorophyll a/b and carotenoids) contents of B. daigremontianum in response to Cd stress were investigated. The comparison between unexposed and exposed B. daigremontianum groups revealed gradual reductions of photosynthetic pigment contents (-40.57% for chlorophyll a, -37.63% for chlorophyll b, -36.27% for total chlorophyll, -20.58% for chlorophyll a/b and -37.66% for carotenoids) at 400 pM and a genomic instability as Cd concentration increases. The results indicated that changes in RAPD-PCR profiles following Cd treatments included a variation in band intensities, a loss of normal bands, and the appearance of new bands compared to unexposed plantlets. Cd concentrations of the collected samples were measured by employing ICP-OES during the study. The concentrations of Cd at 400 mu M Cd treatment were increased significantly in leaves (-5.03 fold), stems (-6.28 fold) and roots (-3.90 fold) of B. daigremontianum. The present study evidences that as an investigation tool for environmental toxicology, the RAPD technique can be useful and can be applied as a suitable biomarker assay for the detection of genotoxic effects of Cd pollution on plants 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.

Asılbek ÇEKEEV

Proceedings Paper | 2019 | Filomat33 ( 5 )

A number of basic properties of R-compact spaces in the category Tych of Tychonoff spaces and their continuous mappings are extended to the category ZUnif of uniform spaces with the special normal bases and their coz-mappings.

Asılbek ÇEKEEV

Proceedings Paper | 2023 | AIP Conference Proceedings2879 ( 1 )

As it is well known, there are various constructions of the R-compactification (Hewitt real compactification) of a uniform space [13], [15]. In this work we propose a new construction of the R-compactification (Hewitt real compactification) of a uniform space. Keyword: A0-boundedness; R-compactification; R-completeness.; R-extension

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

Dağıstan ŞİMŞEK | Burak OĞUL

Proceedings Paper | 2019 | Filomat33 ( 5 )

In this paper, solution of the following difference equation is examined x(n+1) = x(n-17)/1+x(n-5).x(n-11) where the initial conditions are positive reel numbers.