Mehmet Emin Meral | Yüzüncü Yıl üniversitesi (original) (raw)

Papers by Mehmet Emin Meral

IEEE Transactions on Power Delivery

Electric vehicle (EV) charging stations draw nonlinear currents, which makes the distribution net... more Electric vehicle (EV) charging stations draw nonlinear currents, which makes the distribution network unbalanced, distorted, and results in power quality (PQ) issues. These PQ issues are mitigated in this work through high-performance control of the shunt active power filter (SAPF). In the proposed method, a linear Kalman filter (LKF) has been applied to grid voltage and load current signals for harmonic and disturbance robust estimation purpose. Unlike the conventionally used orthogonal vector model, in this work, phase angle vector model together with a simple to tune phase-locked loop (PLL) has been considered for the LKF implementation. DC-link voltage regulation and charging of the DC-link capacitor has been obtained by proposing a Luenberger observer-based super twisting sliding mode control (ST-SMC), which has fast dynamic response and lower voltage ripples compared to similar other existing control methods. This results in significant reduction in size, cost and loss together with lifetime enhancement of the DC-link capacitor. Rigorous sensitivity analysis is conducted to analyze the robustness of the developed method. The proposed control technique achieves fast response time and satisfy the harmonic requirements as specified in the IEEE Std. 519 under various grid and load disturbances. Comparative quasi-real time validation results are presented by using digital signal processor (DSP) based processor-in-the-loop (PIL) with another recently proposed control strategy to verify the performance enhancement by the developed method.

2022 14th International Conference on Electronics, Computers and Artificial Intelligence (ECAI)

Electric Power Systems Research

2022 IEEE Kansas Power and Energy Conference (KPEC)

Sustainable Energy, Grids and Networks

Electrical Engineering, 2017

The voltage or current harmonics and unbalancing have severe influence on control of various appl... more The voltage or current harmonics and unbalancing have severe influence on control of various applications such as power quality devices, distributed generation systems, power converter devices, electric vehicle chargers and electric motors. Orthogonal d−q signals are significantly a part of controller for these applications. This paper proposes a new synchronization method based on integration average filter (AF) into conventional phase locked loop (PLL) in order to attenuate negative effect of voltage harmonics and unbalanced on orthogonal d−q signals for controller. Although some advanced techniques in the literature ensure good performances, uses of multiple filters reduce dynamic response and suffer from computational burden. The proposed improved AF-PLL has simple structure and implementation. It provides fast phase detection, fast dynamic response and removes ripple errors of voltage unbalance and harmonics. The performance of the filter-based PLL is evaluated in terms of balanced, unbalanced condition and harmonics distortion. The effectiveness and reliability of the proposed AF-PLL are demonstrated and discussed by means of comparative conventional PLL and advanced PLL in the literature. PSCAD/EMTDC is used for simulation and examination of all PLLs.

Neural Computing and Applications, 2007

Page 1. ORIGINAL ARTICLE Extraction of voltage harmonics using multi-layer perceptron neural netw... more Page 1. ORIGINAL ARTICLE Extraction of voltage harmonics using multi-layer perceptron neural network Mehmet Tümay Æ M. Emin Meral Æ K. C¸ ag˘atay Bayindir Received: 8 March 2007 / Accepted: 5 October 2007 / Published ...

30th Annual Conference of IEEE Industrial Electronics Society, 2004. IECON 2004

In this paper, a practical thyristor-based 3-phase sag/swell/outage generator (disturbance genera... more In this paper, a practical thyristor-based 3-phase sag/swell/outage generator (disturbance generator) is designed to test various power quality mitigation devices (PQMDs), such as solid state transfer switch (SSTS), static voltage compensator (SVC), and uninterruptible power supply. The latest technological disturbance generators (DGs) and the proposed DG are comprehensively discussed and compared with focus on usefulness, economic aspects, and simplicity. The proposed DG is used for experimentally generating different fault conditions and testing a SSTS. The comparisons and analyses show that the proposed DG is an optimum and simple solution to generate sag, swell, unbalance, overvoltage, undervoltage, and outage to test PQMDs.

2009 International Conference on Electrical and Electronics Engineering - ELECO 2009, 2009

Use of multilevel inverters is becoming more popular in the recent years. Various topologies and ... more Use of multilevel inverters is becoming more popular in the recent years. Various topologies and modulation methods have been reported for utility and drive applications in the recent literature. Hybrid multilevel structures are the new multilevel inverter topologies where the cascaded series inverters have different internal DC bus voltages and/or modulated quite differently. This paper introduces a novel switching signals generation (modulation) method for hybrid multilevel inverters. This method is new and based on reference signal tracking. The structure of modeled hybrid multilevel inverter and operating principles of the proposed method are presented. The proposed method is verified by computer simulations using PSCAD/EMTDC. The waveform and THD values are presented and analyzed, which prove the validity of the proposed method.

Uludağ University Journal of The Faculty of Engineering, 2009

The industry sector has been rapidly growing in Turkey. It is necessary for Turkish industry to i... more The industry sector has been rapidly growing in Turkey. It is necessary for Turkish industry to identi- fy its present level of power quality (PQ) and to know about the cost effective PQ improvement devices for higher efficiency and profitability. To this aim, a wide literature survey for PQ problems and standards was per- formed. Comprehensive questionnaire form concerned power quality knowledge, mitigation methods of PQ problems, real experienced problems and PQ related damages were directed to 24 industrial plants in south in- dustrial districts of Turkey. The key results from the questionnaire survey are presented and the available and new technological solutions are offered analyzing the results. This study will be useful reference for other devel- oping countries.

Universal Journal of Electrical and Electronic Engineering, 2016

Renewable energy sources (RES) like the solar and wind can't produce energy all the time due to d... more Renewable energy sources (RES) like the solar and wind can't produce energy all the time due to depending air condition. But Fuel Cells (FCs) can be stored until it's needed. Power electronics plays an important role in converting the input power which is suitable delivered to the utility grid. Voltage source inverter (VSI) is the most widely used solution for connecting a low power RES tied the grid. This paper present grid tied fuel cell system using single phase phase-locked loop (PLL) based second order generalized integrator (SOGI) with proportional integral (PI) and proportional resonant (PR) current/power controllers. The SOGI algorithm is used with PLL in order to synchronize grid phase and amplitude. Solid oxide fuel cell (SOFC) which is one of FC types is analysed under constant and various DC load. Controllers of the PI and PR are discussed in order to obtain the control of inverter along with the variation of active power and grid voltage drop. The system is modelled and simulated using PSCAD/EMTDC software package. Simulation results show the effectiveness of both the controllers and PLL technique based SOGI for the synchronising of the SOFC systems with the single phase grid successfully.

Journal of Power Electronics, 2013

The most common power quality problems in distribution systems are related to unbalanced voltage ... more The most common power quality problems in distribution systems are related to unbalanced voltage sags. Voltage sags must be detected quickly and corrected in a minimum amount of time. One of the most widely used methods for sag detection is based on the d-q transformation. This method has the disadvantage of missing the detection of unbalanced faults, because this method uses a voltage sag level signal obtained from the average of 3 phases for sag detection. In this paper, an adaptive filter sag detection method is proposed for Dynamic Voltage Restorers (DVR) under unbalanced fault conditions. The proposed DVR controller is able to detect balanced, unbalanced and single phase voltage sags. A novel reference voltage generation method is also presented. To validate the proposed control methods, a 3-phase DSP controlling a DVR prototype with a power rating of 1.5-kVA has been developed. Finally, experimental results are presented to verify the performance of the proposed control methods.

DergiPark (Istanbul University), 2009

Elektrik; sanayide, ticari işletmelerde ve konutlarda en çok kullanılan enerji çeşididir. Doğal k... more Elektrik; sanayide, ticari işletmelerde ve konutlarda en çok kullanılan enerji çeşididir. Doğal kaynakların hızla tüketilmesi, artan çevre kirliliği ve yüksek miktarlardaki enerji fiyatları, elektrik enerjisinin her noktada daha verimli ve etkin kullanılmasını gerektirmektedir. Bu çalışma, elektrik enerjisi verimliliğini arttırabilecek yöntemler üzerine bir çalışma olup, elektrik enerjisi tasarrufunun arttırılmasına katkıda bulunmayı amaçlamaktadır. Enerji verimliliğini arttırabilecek yöntemler sayısal örneklerle sunulmuş ve gerekli önerilerde bulunulmuştur.

Electrical Engineering, 2014

The most common power quality problems in electrical distribution systems are related to single p... more The most common power quality problems in electrical distribution systems are related to single phase to ground faults causing unbalanced voltage sags. One of the most widely used methods for sag detection is conventional method based on d-q transformation. However, this method has the disadvantage of missing the detection of single phase-to-ground faults, because this method uses a voltage sag level signal obtained from the average of three phase voltages for sag detection. In this paper, an adaptive filter based sag detection method is proposed for solid state transfer switch (SSTS). Simulation models of the SSTS using the adaptive filter based proposed and d-q transformation based methods are developed by PSCAD/EMTDC program. Simulation results show that, the SSTS using proposed method is able to detect three phases and/or single phase voltage sags, correctly. To validate the simulation model and results, a three-phase experimental SSTS prototype is successfully constructed and experimental results are presented.

TEZ7480Tez (Doktora) -- Çukurova Üniversitesi, Adana, 2009.Kaynakça (s.199-211) var.xxiii, 212 s.... more TEZ7480Tez (Doktora) -- Çukurova Üniversitesi, Adana, 2009.Kaynakça (s.199-211) var.xxiii, 212 s. : rnk.res. ; 29 cm.A power quality problem is any voltage, current deviations that results in failure or misoperation of customer equipment. There are two classes of power quality problems according to causes. The first class covers voltage sags/swells and momentary interruptions mostly caused by faults in the power system. The second covers problems due to low quality of current drawn by the load caused by nonlinear loads. In the recent years, power electronics based Custom Power (CP) devices that solve these problems attract attention. However, the system formed by putting together the CP devices in an industrial/commercial power park is known as Custom Power Park (CPP). The CPP provides continuous and high quality power to the customers having sensitive loads.Tuketici ekipmanının hatalı calısmasına veya devre dısı kalmasına neden olan her turlu gerilim ve akım sapması, guc kalitesi p...

SSRN Electronic Journal, 2021

2021 IEEE International Power and Renewable Energy Conference (IPRECON), 2021

With the growing usage of primary energy resources (PERs), energy storage technologies have been ... more With the growing usage of primary energy resources (PERs), energy storage technologies have been required to fulfill a balance between supply and demand. Therefore, a control scheme combining superconducting magnetic energy storage (SMES) control and overvoltage and under-voltage prevention control is proposed for SMES based inverter connected to utility grid under various grid voltage disturbances. One of the contributions of this paper is to maximize positive voltage sequence and minimize negative voltage sequences to eliminate the voltage and current imbalances. Besides, the control of the SMES has been performed depending on the regulation of the DC-link capacitor voltage. Also, the voltage support guarantees the safe operation of the three phase inverter. Theoretical analysis and PSCAD/EMTDC based results are conducted to show the feasibility of the voltage and power quality improvement.

gazi university journal of science, 2011

Decrease in the cost of power electronic devices and improvement in the efficiency of both power ... more Decrease in the cost of power electronic devices and improvement in the efficiency of both power converters and energy storage components have increased the applicability of new technological solutions such as Custom Power (CP) and Flexible AC Transmission Systems (FACTS) Devices. Active Power Filter (APF) is one of the CP devices and can mitigate harmonics, reactive power and unbalanced load currents originating from load side. In this study, a comprehensive review of APF studies, the advantages and disadvantages of each presented techniques are presented. The study also helps the researchers to select the optimum control strategies and power circuit configuration for APF applications. Keywords: Active Power Filter, Power Quality, Literature Review, Custom Power. .

Ozet: Gunumuzde, guc elektronigi elemanlari ve devreleri uretilen giris gucunu sebekeye iletmek i... more Ozet: Gunumuzde, guc elektronigi elemanlari ve devreleri uretilen giris gucunu sebekeye iletmek icin onemli rol oynar. Gerilim kaynakli eviriciler, bu amacla yaygin sekilde kullanilan bir cozumdur. Şebeke ile guc alisverisini duzenlemek icin ve harmonik bilesenleri azaltmak icin literaturde farkli kontrol yontemleri onerilmistir. Bu calismada, sebekeye bagli SOGI tabanli tek fazli PLL kullanilan tek fazli evirici sisteminin PR ve HCC kullanilarak guc/akim kontrolu yapilmistir. SOGI algoritmali PLL vasitasiyla, normalde uc fazli sebekelerde kullanilan geleneksel PLL’ in tek fazli sebekede kullanimi saglanarak, sebeke frekans ve gerilim icin senkronizasyonunu saglanmistir. PR ve HCC tabanli kontrolculer, evirici ile sebeke arasindaki aktif gucun degisimini saglayan kontrolculerdir. SOGI tabanli PLL sistemi ve PR ve HCC tabanli kontrolcu kullanilan evirici-sebeke sistemleri PSCAD/EMTDC paket yazilimi kullanilarak analiz edilmis, her iki yontem harmonik ve dinamik cevap acisindan karsil...