Browsing by Author "Ceylan, Oğuzhan"
Now showing items 1-20 of 24
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A Novel Approach for Voltage Control in Electrical Power Distribution Systems
Authors:Ceylan, Oğuzhan; Dimitrovski, Aleksandar; Starke, Michael; Tomsovic, Kevin
Publisher and Date:(IEEE, 2018)This paper proposes a novel approach for voltage control in 3-phase unbalanced distribution systems. The approach is based on the change of the magnetizing reactances of the voltage regulators in the system. We used an augmented Lagrangian-based optimization model to determine the optimal settings on a modified IEEE 123 Bus Test System with large PV penetration. Simulations were performed on a minute-based resolution either by controlling regulators or by controlling the magnetizing reactances of ...
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Active and Reactive Power Load Profiling Using Dimensionality Reduction Techniques and Clustering
Authors:Yetkin, E. Fatih; Ceylan, Oğuzhan; Papadopoulos, Theofilos A.; Kazaki, Anastasia G.; Barzegkar-Ntovom, Georgios A.
Publisher and Date:(Institute of Electrical and Electronics Engineers Inc., 2019)This paper proposes a methodology to characterize active and reactive power load profiles. Specifically, the approach makes use of fast Fourier Transform for conversion into frequency domain, principle component analysis to reduce the dimension and K-means++ to determine the representative load profiles. The data set consists of five-year measurements taken from the Democritus University of Thrace Campus. Test days were also classified as working and non-working. From the results it is observed ...
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An Adaptive Affinity Matrix Optimization for Locality Preserving Projection via Heuristic Methods for Hyperspectral Image Analysis
Authors:Taşkın, Gülşen; Ceylan, Oğuzhan
Publisher and Date:(IEEE-Inst Electrıcal Electronıcs Engıneers Inc, 2019)Locality preserving projection (LPP) has been often used as a dimensionality reduction tool for hyperspectral image analysis especially in the context of classification since it provides a projection matrix for embedding test samples to low dimensional space. However, the performance of LPP heavily depends on the optimization of two parameters of the graph affinity matrix: k-nearest neighbor and heat kernel width, when one considers an isotropic kernel. These two parameters might be optimally ...
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Assessment of Harmonic Distortion on Distribution Feeders with Electric Vehicles and Residential PVs
Authors:Ceylan, Oğuzhan; Paudyal, Sumit; Dahal, Sudarshan; Karki, Nava R.
Publisher and Date:(IEEE, 2017)Power-electronic interfacing based devices such as photovoltaic (PV) panels and electric vehicles (EVs) cause voltage/current harmonic distortions on the power grid. The harmonic current profiles from EVs and PVs depend on the design of the controllers integrated to the PV inverters and EV chargers. Similarly the voltage and current harmonic distortions on a grid change throughout the day as the PV output power number of grid connected EVs and the other load pattern change. In this context we ...
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Branch outage solution using particle swarm optimization
For post outage MW line flows and voltage magnitude calculations most of the methods use linear methods because of their simplicity. Especially for reactive power flow calculations one can face high errors. In this paper we use a minimization method that minimizes the errors resulting from the linear system model implementation. We solve the optimization problem using particle swarm optimization. We give some outage examples using IEEE 14 bus IEEE 30 bus and IEEE 57 bus data and compare the results ...
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Comparative Study of Active Power Curtailment Methods of PVs for Preventing Overvoltage on Distribution Feeders
Authors:Paudyal, Sumit; Bhattarai, Bishnu P.; Tonkoski, Reinaldo; Dahal, Sudarshan; Ceylan, Oğuzhan
Publisher and Date:(IEEE, 2018)Overvoltage is one of the major issues on distribution grids with high penetration of photovoltaic (PV) generation. Overvoltage could be prevented through the control of active/reactive power of PVs. However given the high R/X ratio of low voltage feeders voltage control by using reactive power would not be as effective as using active power. Therefore active power curtailment (APC) of PVs though not desirable becomes necessary at times to prevent the overvoltage issues. Existing literature is ...
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A Comparative Study of Metaheuristic Algorithms for Wave Energy Converter Power Take-Off Optimisation: A Case Study for Eastern Australia
Authors:Amini, Erfan; Golbaz, Danial; Asadi, Rojin; Nasiri, Mandieh; Ceylan, Oğuzhan; Nezhad, Meysam Majidi; Neshat, Mehdi
Publisher and Date:(MDPI, 2021)One of the most encouraging sorts of renewable energy is ocean wave energy. In spite of a large number of investigations in this field during the last decade, wave energy technologies are recognised as neither mature nor broadly commercialised compared to other renewable energy technologies. In this paper, we develop and optimise Power Take-off (PTO) configurations of a well-known wave energy converter (WEC) called a point absorber. This WEC is a fully submerged buoy with three tethers, which was ...
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A comparative study of surrogate based learning methods in solving power flow problem
Due to increasing volume of measurements in smart grids, surrogate based learning approaches for modeling the power grids are becoming popular. This paper uses regression based models to find the unknown state variables on power systems. Generally, to determine these states, nonlinear systems of power flow equations are solved iteratively. This study considers that the power flow problem can be modeled as an data driven type of a model. Then, the state variables, i.e., voltage magnitudes and phase ...
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Comparison of post outage bus voltage magnitudes estimated by harmony search and differential evolution methods
Contingency studies are indispensable tools of both the power system planning and operational studies. Real time implementation of operational problems makes necessary the use of high speed computational methods while requiring reasonable accuracies. On the other hand, accuracy of the results and the speed of calculation depend on branch outage modeling as well as solution algorithm used. This paper presents a comparison of post outage bus voltage magnitudes calculated by two meta-heuristic ...
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Coordinated Electric Vehicle Charging With Reactive Power Support to Distribution Grids
Authors:Wang, Jingyuan; Bharati, Guna R.; Paudyal, Sumit; Ceylan, Oğuzhan; Bhattarai, Bishnu P.; Myers, Kurt S.
Publisher and Date:(IEEE, 2019)We develop hierarchical coordination frameworks to optimally manage active and reactive power dispatch of number of spatially distributed electric vehicles (EVs) incorporating distribution grid level constraints. The frameworks consist of detailed mathematical models which can benefit the operation of both entities involved i.e. the grid operations and EV charging. The first model comprises of a comprehensive optimal power flow model at the distribution grid level while the second model represents ...
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Generic dynamic load modelling using cluster analysis
Authors:Barzegkar-Ntovom, Georgios A.; Ceylan, Oğuzhan; Papadopoulos, Theofilos A.; Yetkin, E. Fatih
Publisher and Date:(IEEE, 2018)In this paper a new generic load modelling procedure is proposed based on the application of cluster analysis on load model parameters identified from measured dynamic responses. The performance of the proposed approach is assessed using measurements obtained from a low-voltage laboratory scale test configuration. In order to develop robust generalized load models applicable to a wide range of operating conditions different load compositions operating conditions and voltage disturbances are ...
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GRAPH OPTIMIZED LOCALITY PRESERVING PROJECTION VIA HEURISTIC OPTIMIZATION ALGORITHMS
Dimensionality reduction has been an active research topic in hyperspectral image analysis due to complexity and non-linearity of the hundreds of the spectral bands. Locality preserving projection (LPP) is a linear extension of the manifold learning and has been very effective in dimensionality reduction compared to linear methods. However, its performance heavily depends on construction of the graph affinity matrix, which has two parameters need to be optimized: k-nearest neighbor parameter and ...
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Grey Wolf optimizer for allocation and sizing of distributed renewable generation
Authors:Ahmadi, Bahman; Ceylan, Oğuzhan; Özdemir, Aydoğan
Publisher and Date:(Institute of Electrical and Electronics Engineers Inc., 2019)Increasing penetration of distributed energy resources (DERs) have brought operational and control philosophy changes in Smart Grids (SGs). Renewable energy based technologies are becoming more important due to their economic and environmental impacts. Distributed generations (DGs) in the form of small renewable energy resources such as solar photovoltaics (PVs) and Wind Turbines (WTs) are connected in radial distribution networks near to the loads. This paper presents optimal siting and sizing ...
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Harmony Search Algorithm Based Management of Distributed Energy Resources and Storage Systems in Microgrids
Authors:Ceylan, Oğuzhan; Sezgin, Mustafa Erdem; Goel, Murat; Verga, Maurizio; Lazzari, Riccardo; Kwaye, Marcel Pendieu; Sandroni, Carlo
Publisher and Date:(MDPI, 2020)Microgrids are composed of distributed energy resources (DERs), storage devices, electric vehicles, flexible loads and so on. They may either operate connected to the main electricity grid (on-grid operation) or separated from the grid (islanded operation). The outputs of the renewable energy sources may fluctuate and thus can cause deviations in the voltage magnitudes especially at islanded mode. This may affect the stability of the microgrids. This paper proposes an optimization model to efficiently ...
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Impacts of Load and Generation Volatilities on the Voltage Profiles Improved by Distributed Energy Resources
Authors:Ahmedi, Bahman; Ceylan, Oğuzhan; Özdemir, Aydoğan
Publisher and Date:(Institute of Electrical and Electronics Engineers Inc., 2020)Weather-dependent distributed renewable energy sources such as photovoltaics (PVs) and wind turbines (WT) are increasingly being connected to distribution networks (DNs). Increased penetration of these intermittent sources brought the necessity of using energy storage systems (ESSs) to achieve the intended benefits. This study presents an optimization process to determine optimal numbers, sizes, locations and distributed energy resources (DERs) as well as to determine the optimal operating strategy ...
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Multi-Agent model of electricity networks - a perspective on distribution network charges
Authors:Pisica, Ioana; Ceylan, Oğuzhan
Publisher and Date:(Institute of Electrical and Electronics Engineers Inc., 2019)In the UK, DNOs are regulated by Ofgem to use two common distribution use of system charging methodologies: Common Distribution Charging Methodology and Extra-High Voltage Distribution Charging Methodology. To account for the changing landscape of the energy sector, Ofgem has recently published a consultation paper on changes to DUoS charging structure. This paper looks into the implications of distribution network charging in consumer-level adoption of low carbon technologies and vice-versa, using ...
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Multi-verse optimization algorithm- and salp swarm optimization algorithm-based optimization of multilevel inverters
Renewable energy sources are installed into both distribution and transmission grids more and more with the introduction of smart grid concept. Hence, efficient usage of cascaded H-bridge multilevel inverters (MLIs) for power control applications becomes vital for sustainable electricity. Conventionally, selective harmonic elimination equations need to be solved for obtaining optimum switching angles of MLIs. The objective of this study is to obtain switching angles for MLIs to minimize total ...
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Nodal Sensitivity-Based Smart Inverter Control for Voltage Regulation in Distribution Feeder
Authors:Ceylan, Oğuzhan; Paudyal, Sumit; Pisica, Ioana
Publisher and Date:(IEEE Electron Devices Society, 2021)Overvoltage is one of the issues in distribution grids with high penetration of photovoltaics (PVs). Centralized or droop-based methods of active power curtailment (APC) and/or reactive power control of PVs are viable solutions to prevent overvoltage. This article proposes two distributed methods to control PV inverters, which are based on nodal sensitivities. Then, the performance of the proposed methods is compared with two commonly used control methods, i.e., a distributed method that follows ...
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Optimal Allocation Of Multi-Type Distributed Generators For Minimization Of Power Losses In Distribution Systems
Authors:Ahmadi, Bahman; Ceylan, Oğuzhan; Özdemir, Aydoğan
Publisher and Date:(Institute of Electrical and Electronics Engineers Inc., 2019)Distributed generation (DG), including photovoltaics (PVs), wind turbines (WTs) are becoming vital for Active Distribution Networks (ADN). Therefore, optimal sizing and allocation of these units can improve voltage profiles and reduce active power losses. This study concentrates on optimal allocation and sizing of two kinds of DG units (PVs and WTs) with 1 MW maximum size limits, due to the regulations in Turkey. The Whale optimization algorithm (WOA) and Grey wolf optimization algorithm (GWO) are ...
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Optimization of Graph Affinity Matrix with Heuristic Methods in Dimensionality Reduction of Hypespectral Images
Hyperspectral images include hundreds of spectral bands, adjacent ones of which are often highly correlated and noisy, leading to a decrease in classification performance as well as a high increase in computational time. Dimensionality reduction techniques, especially the nonlinear ones, are very effective tools to solve these issues. Locality preserving projection (LPP) is one of those graph based methods providing a better representation of the high dimensional data in the low-dimensional space ...