Browsing by Author "Yoldas, Yeliz"

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Cloud Induced PV Impact on Voltage Profiles for Real Microgrids
(IEEE, 345 E 47TH ST, NEW YORK, NY 10017 USA, 2018) Kocer, Mustafa Catagatay; Yoldas, Yeliz; Goren, Selcuk; Onen, Ahmet; Alan, Irfan; Al-Agtash, Salem; Azzopardi, Brain; Martensen, Nis; Martinez-Ramos, Jose L.; Tzovaras, Dimitrios; Hadjidemetriou, Lenos; Khiat, Mounir; Camilleri, Tim; Borg, Nicholas; 0000-0002-5320-4213; AGÜ, Mühendislik Fakültesi, Elektrik - Elektronik Mühendisliği Bölümü
Integration of renewable energy sources (RESs) into power systems has been a popular topic for a long time. Due to government policies and incentives, it will be more popular in the future since it is a free and environment-friendly nature. Besides its advantages, photovoltaic (PV) generation causes some serious problems to the grid. Since PV generation directly depends on the solar irradiance, cloud movements can cause sudden changes on the output of PV power and this results in some power issues in the system such as voltage violations, reverse power flow, voltage fluctuations. These types of issues complicate to maintain voltage within compulsory levels at customer sides. Thus, cloud-induced transients in PV power are seen as a potential handicap for the future expansion of renewable energy resources. This study investigates effects of instantaneous changes in PV power on the customer side voltage levels. Daily PV power output and voltage profiles were simulated using a real-world microgrid design that will be implemented in the Malta College of Arts Science and Technology(MCAST) Campus.
Distribution Automation Effects on Reliability during Major Contingencies
(IEEE, 2018) Yoldas, Yeliz; Onen, Ahmet; Alan, Irfan; Broadwater, Robert P.; AGÜ, Mühendislik Fakültesi, Elektrik & Elektronik Mühendisliği Bölümü;
Distribution automation affects reliability by providing faster restoration ability. In this study, the effect of distribution automation on radial distribution circuits during substation failures at peak load is investigated. The ultimate goal is to compare circuit automation to manual operation, where the comparison evaluates planning criteria reliability for customer interruption hours. The results show that distribution automation can improve reliability measurements such as SAIDI, SAIFI and CAIDI.
Dynamic rolling horizon control approach for a university campus
(Elsevier Ltd, 2022) Yoldas, Yeliz; Goren, Selcuk; Onen, Ahmet; Ustun, Taha Selim; 0000-0002-5320-4213; 0000-0001-7086-5112; 0000-0002-2413-8421; AGÜ, Mühendislik Fakültesi, Elektrik - Elektronik Mühendisliği Bölümü; Yoldaş, Yeliz; Gören, Selçuk; Önen, Ahmet
An energy management system based on the rolling horizon control approach has been proposed for the grid-connected dynamic and stochastic microgrid of a university campus in Malta. The aims of the study are to minimize the fuel cost of the diesel generator, minimize the cost of power transfer between the main grid and the micro grid, and minimize the cost of deterioration of the battery to be able to provide optimum economic operation. Since uncertainty in renewable energy sources and load is inevitable, rolling horizon control in the stochastic framework is used to manage uncertainties in the energy management system problem. Both the deterministic and stochastic processes were studied to approve the effectiveness of the algorithm. Also, the results are compared with the Myopic and Mixed Integer Linear Programming algorithms. The results show that the life span of the battery and the associated economic savings are correlated with the SOC values.
Energy Trading on a Peer-to-Peer Basis between Virtual Power Plants Using Decentralized Finance Instruments
(MDPI, 2022) Seven, Serkan; Yoldas, Yeliz; Soran, Ahmet; Alkan,Gulay Yalcin; Jung, Jaesung; Ustun, Taha Selim; Onen, Ahmet; 0000-0003-2611-720X; 0000-0003-3929-8126; 0000-0001-7086-5112; AGÜ, Mühendislik Fakültesi, Bilgisayar Mühendisliği Bölümü; Seven, Serkan; Yalçın Alkan, Gülay; Önen, Ahmet
Over time, distribution systems have begun to include increased distributed energy resources (DERs) due to the advancement of auxiliary power electronics, information and communication technologies (ICT), and cost reductions. Electric vehicles (EVs) will undoubtedly join the energy community alongside DERs, and energy transfers from vehicles to grids and vice versa will become more extensive in the future. Virtual power plants (VPPs) will also play a key role in integrating these systems and participating in wholesale markets. Energy trading on a peer-to-peer (P2P) basis is a promising business model for transactive energy that aids in balancing local supply and demand. Moreover, a market scheme between VPPs can help DER owners make more profit while reducing renewable energy waste. For this purpose, an inter-VPP P2P trading scheme is proposed. The scheme utilizes cutting-edge technologies of the Avalanche blockchain platform, developed from scratch with decentralized finance (DeFi), decentralized applications (DApps), and Web3 workflows in mind. Avalanche is more scalable and has faster transaction finality than its layer-1 predecessors. It provides interoperability abilities among other common blockchain networks, facilitating inter-VPP P2P trading between different blockchain-based VPPs. The merits of DeFi contribute significantly to the workflow in this type of energy trading scenario, as the price mechanism can be determined using open market-like instruments. A detailed case study was used to examine the effectiveness of the proposed scheme and flow, and important conclusions were drawn.
Enhancing smart grid with microgrids: Challenges and opportunities
(PERGAMON-ELSEVIER SCIENCE LTDTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND, 2017) Yoldas, Yeliz; Onen, Ahmet; Muyeen, S. M.; Vasilakos, Athanasios V.; Alan, Irfan; AGÜ, Mühendislik Fakültesi, Elektrik - Elektronik Mühendisliği Bölümü; Yoldas, Yeliz; Onen, Ahmet; Alan, Irfan
The modern electric power systems are going through a revolutionary change because of increasing demand of electric power worldwide, developing political pressure and public awareness of reducing carbon emission, incorporating large scale renewable power penetration, and blending information and communication technologies with power system operation. These issues initiated in establishing microgrid concept which has gone through major development and changes in last decade, and recently got a boost in its growth after being blessed by smart grid technologies. The objective of this paper is to presents a detailed technical overview of microgrid and smart grid in light of present development and future trend. First, it discusses microgrid architecture and functions. Then, smart features are added to the microgrid to demonstrate the recent architecture of smart grid. Finally, existing technical challenges, communication features, policies and regulation, etc. are discussed from where the future smart grid architecture can be visualized.
Implementation of capital deferral algorithm in real distribution systems considering reliability by managing major faults
(SPRINGER, ONE NEW YORK PLAZA, SUITE 4600, NEW YORK, NY, UNITED STATES, 2019) Yoldas, Yeliz; Onen, Ahmet; Broadwater, Robert; Alan, Irfan; AGÜ, Mühendislik Fakültesi, Elektrik - Elektronik Mühendisliği Bölümü
Distribution automation technology plays a key role on power system reliability by providing faster detection, isolating the faulted area and restoring the fault. In this paper, the impacts of distribution automation are considered on radial distribution system in the event of substation transformer bank malfunction at maximum load level with the aim of deferring the big capital investments. The aim of the proposed method is not only to increase physical impact such as the reliability but also to monetize physical measures into significant economic benefits by deferring the overall investment costs. The proposed algorithm is tested with the real distribution system data, and it is shown that it can obtain remarkable economic benefits by deferring the larger capital equipment investments by making smaller investments in distribution automation.
Implementation of cost benefit analysis of vehicle to grid coupled real Micro-Grid by considering battery energy wear: Practical study case
(SAGE PUBLICATIONS LTD, 1 OLIVERS YARD, 55 CITY ROAD, LONDON EC1Y 1SP, ENGLAND, 2020) Koubaa, Rayhane; Yoldas, Yeliz; Goren, Selcuk; Krichen, Lotfi; Onen, Ahmet; 0000-0002-5320-4213; AGÜ, Mühendislik Fakültesi, Elektrik - Elektronik Mühendisliği Bölümü
The proposed research represents a spin-off of the Malta College of Arts, Science and Technology (MCAST) Micro-Grid (MG) project. Particularly, economic impact of Electric Vehicles (EV) integration into the MG is investigated in this paper. The MCAST MG consists of photovoltaic generation unit, a diesel generator and a battery storage system. In this paper, a Vehicle-to grid (V2G) concept is considered where utilities can profit from controlled energy trading operations according to EVs availability. EVs are categorized under different profiles considering energy and time availability of owners typical work hours. V2G energy cost is estimated based on battery energy wear due V2G extra cycling and refunded to EVs owners. As most of developed V2G studies don't consider real world input data or/and EV battery aging cost in system modeling and evaluation, the present paper presents a reliable study as it considers a real life MG with in field measurement input data and appropriate battery degradation model. The adopted model represents a linear approximation with a minimum error value to make a suitable tradeoff of computational complexity and accuracy of obtained results. Economic assessment of the system according to the proposed energy management is performed, where results indicate that the V2G system assisted the MG operation during high electricity price period and achieved economic profit to EVs owners. According to numerical results, V2G energy trading achieved 29.90 EUR of gross selling revenues with only 4.46 EUR as battery degradation cost which makes a 16.41% average cost reduction of daily MG operation cost.
Provision of Ancillary Services by a Smart Microgrid: An OPF Approach
(IEEE, 2018) Ramos, Jose L. Mart´ınez; Marcolini, Alejandro Marano; Lopez, Francisco P. Garc´ıa; Yravedra, Fernando Almagro; Onen, Ahmet; Yoldas, Yeliz; Khiat, Mounir; Ghomri, Leila; Fragale, Nunziatina; AGÜ, Mühendislik Fakültesi, Elektrik & Elektronik Mühendisliği Bölümü;
Ancillary services are all services required by the transmission (TSO) or distribution system operator (DSO) to maintain the integrity and stability of the transmission or distribution system as well as the power quality. Ancillary services that can be provided by a microgrid in grid-connected operation are frequency control support, voltage control support, congestion management, reduction of grid losses, and improvement of power quality. This paper presents the optimization problems used in the 3DMicroGrid project to determine the set-points of the different resources present in the microgrid to provide ancillary services to the power system in grid-connected operation: frequency control, voltage control and load curtailment. Results of the optimization of the pilot microgrid used in 3DMicroGrid are presented.