Papers by Mehmet Hakan Hocaoglu
A faulty feeder selection method for distribution network with unintentional resonance in zero sequence circuit
Electric Power Systems Research
Sustainability, 2022
Energy storage systems (ESSs) and demand-side management (DSM) strategies have significant potent... more Energy storage systems (ESSs) and demand-side management (DSM) strategies have significant potential in providing flexibility for renewable-based distribution networks. Therefore, combining ESSs and DSM strategies with renewable energy sources (RESs) to solve economic, operational, environmental, and power-related political issues has received special attention from power system planners around the world. In this regard, developed countries, which are pioneers in renewable technologies, have proposed various supportive policies and practices for the widespread use of ESSs and DSM strategies in the context of distribution networks. Hence, this paper performs a comprehensive review of the most recent actions taken to build the infrastructure necessary to achieve 100% renewable energy. On this basis, this paper firstly surveys the necessity of using ESSs and DSM strategies in renewable-based distribution networks. Then, the existing policies and incentive programs implemented in differ...
Energies, 2021
The topology of a distribution network can be represented by a bus injection to branch current (B... more The topology of a distribution network can be represented by a bus injection to branch current (BIBC) matrix. It has been introduced and used for load flow analysis of distribution networks. In this paper, a method for BIBC matrix modification is developed to use in applications which require a topology change representation. Proposed method that reflects the changes in configuration in the system BIBC matrix is implemented in distribution network reconfiguration problem. With providing potential solutions for network operational and planning requirements such as necessitate changes in configurations to transfer the loads to a different substation, ease the loading of equipment, conduct planned maintenance and reduce network losses during the normal operation with renewables, storage and other uprising technologies, reconfiguration may also be useful for emergencies, accidents, attacks and weather-related disasters. The BIBC modification process provides the knowledge of possible sw...
Energies
The synchronous generators (SGs) supplying non-linear loads have harmonically distorted terminal ... more The synchronous generators (SGs) supplying non-linear loads have harmonically distorted terminal voltages. Hence, these distorted terminal voltages adversely affect the performance parameters of the supplied loads such as the power factor, current distortion, losses, and efficiency. To mitigate the harmonic voltages and currents, passive and active filters are generally employed. However, passive filters cause resonance problems, while active filters can cause high costs. On the other hand, in several recent studies to reduce the SG’s terminal voltage harmonic distortion, which depends on the constructional design under the no-loading condition, the conventional DC excitation current has been modulated with AC harmonic components. These field current modulation methods have high computational complexity, and require extra hardware for their implementation. In the present paper, firstly, for the reduction of the terminal voltage harmonic distortion of the SG under non-linear loading ...
Turkish Journal of Engineering Research and Education, 2022
In power systems, the practice of overcurrent protection is more economical and common than the d... more In power systems, the practice of overcurrent protection is more economical and common than the distance protection practice. In addition, overcurrent protection is used in the majority of distribution networks. This makes it necessary to design the coordination of overcurrent relays used in distribution networks in the most appropriate way. Otherwise, the relays cannot work as desired during the fault. In order for the coordination between the overcurrent relays to be effective and selective, the relay setting parameters must be adjusted depending on the network. With the expansion of distribution networks, it has become difficult to calculate or update the relay settings. For this reason, overcurrent relay coordination is designed as an optimization problem with a high number of constraints. At the point of solving the optimization problem, many meta-heuristic algorithms have been developed. In this study, the Greywolf Optimization Algorithm (GWO) for the IEEE 8 Bus test network has been successfully applied and comprehensive performance analysis has been carried out.
Güç sistemlerinde aşırı akım koruma pratiği, mesafe koruma pratiğinden daha ekonomik ve yaygındır. Ayrıca dağıtım şebekelerinin büyük bir çoğunluğunda aşırı akım koruma kullanılmaktadır. Bu durum, dağıtım şebekelerinde kullanılan aşırı akım rölelerin koordinasyonun en uygun şekilde tasarlanmasını gerekli kılmaktadır. Aksi halde sistemde gerçekleşen bir arıza sırasında röleler istenildiği gibi çalışamaz. Aşırı akım röleleri arasında koordinasyonun etkili ve seçici olabilmesi için röle ayar parametrelerinin şebekeye uygun ayarlanması gerekmektedir. Dağıtım şebekelerinin genişlemesi ile birlikte röle ayarlarının hesaplanması veya güncellenmesi zorlaşmıştır. Bu nedenle aşırı akım röle koordinasyonu yüksek sayıda kısıt içeren optimizasyon problemi şeklinde kurgulanmaktadır. Optimizasyon problemini çözümü noktasında ise peç çok meta-sezgisel algoritmalar geliştirilmiştir. Bu çalışmada IEEE 8 Baralı test şebekesi için Bozkurt Optimizasyon Algoritması (BOA) başarılı bir şekilde uygulanmış ve kapsamlı performans analizi gerçekleştirilmiştir.
Renewable resource based DG-unit allocation in distribution systems
Increasing power demand and limited sources give rise to researches for sustainable energy suppli... more Increasing power demand and limited sources give rise to researches for sustainable energy supplies. Renewable energy sources like solar cell, wind turbine, fuel cell, and hydro turbine are the common technologies for sustainable, exhaustless and nonpolluting energy. In recent years, great interests have been directed to integration of embedded resources to the grid. Embedded resources have place in electric power networks as distributed generation units. DG-units have many advantages as providing loss reduction, improving voltage profile, and increasing reliability of system. Using renewable sources as a DG-unit has many parameters to assess. In this paper DG-units which have been considered as renewable resources are integrated at optimal place with optimal size into distribution system. This optimization process is performed with Artificial Bee Colony (ABC) algorithm. ABC algorithm is a meta-heuristic approach inspired by the intelligent foraging behavior of honey bee swarms. ABC algorithm has two parameters to estimate. Therefore updating them for effective values to get higher success is easier than other meta-heuristic methods. ABC algorithm is used in this study to determine DG-unit’s optimal size and place in order to minimize total system power loss. 33 and 69 bus radial test systems and 229 bus real distribution system are used in order to show the performance of ABC algorithm in solving nonlinear optimization problems. Results are compared with grid search method and success of ABC algorithm is approved.
Topraklama sistemlerinin performans analizinde arıza seviyesi kontrolü ve güvenlik kriteri için yeni yaklaşımlar
Comparison of fault current calculation techniques for analysing earthing system performance
The 1997 32 nd Univertsities Power Engineering Conference, UPEC'97. Part 2(of 2), 1997
Recent developments in computer technology and numerical techniques now enable full dynamic studi... more Recent developments in computer technology and numerical techniques now enable full dynamic studies to be carried for fault current calculations. Existing international standards, however, are still based on hand-calculation approaches. Generally, fault current calculations are required to determine fault current interruption requirements and, in the main, consider three-phase balanced faults. However, fault current calculations are also required to establish the extent and structural design of earthing systems, and in this case ...
An Analytic Approach to Determine Maximum Penetration Level of Distributed Generation Considering Power Loss
2018 Twentieth International Middle East Power Systems Conference (MEPCON), 2018
In power system distributed generation has rapidly increased due to many technical, economical an... more In power system distributed generation has rapidly increased due to many technical, economical and environment aspects. Distribution network operators face with challenges lately with integration of distributed generation. The aim to increase distributed generation and make distribution system less attached to central generation release many problems in planning and operating a network. To keep distribution system safe and reliable the effects of distributed generation is to be investigated. Lately, optimal allocation problems give place to high penetration problems. In order to guide distribution network operators for high penetration level of distributed generation in the existing systems with less investment needs new approaches are required. An analytical approach is introduced in this paper to maximize penetration level of distributed generation without increasing total power loss of system. 33-bus and 69-bus test distribution systems and a 229-bus real network are used to implement method and results are presented.
Performance analysis of three‐phase five‐leg transformers under DC bias using a new frequency‐dependent reluctance‐based model
IET Generation, Transmission & Distribution
Performance analysis of three‐phase five‐leg transformers under DC bias using a new frequency‐dependent reluctance‐based model
IET Generation, Transmission & Distribution
Demand Side Management; a New Opportunity for Energy Efficient Data Centers
Artan enerji ihtiyacı ve kısıtlı kaynaklar sürdürülebilir enerji kaynaklarına olan ilgiyi artırmı... more Artan enerji ihtiyacı ve kısıtlı kaynaklar sürdürülebilir enerji kaynaklarına olan ilgiyi artırmıştır. Güneş pili hücresi, rüzgar türbini, yakıt pili ve hidro türbin gibi sürdürülebilir ve çevreye zararsız enerji teknolojileri sıklıkla kullanılmaya başlanmıştır. Son yıllarda şebekeye gömülü kaynaklar entegre etmeye yönelik çalışmalar artmış ve yenilenebilir teknolojiler bu çalışmalara dahil edilmiştir. Elektrik enerji şebekesinde bunlara dağıtık jeneratör ya da yerel elektrik santralleri denmektedir. Yerel elektrik santralleri sistemin kayıplarını azaltırken, gerilim profilini iyileştirip sistemin güvenilirliğini artırmaktadır. Bu avantajlardan yararlanmak için yerel elektrik santrallerinin sisteme uygun yerde ve uygun boyutta yerleştirilmesi gerekir. Bu çalışmada Yapay Arı Kolonisi Algoritması kullanılarak lineer olmayan bu optimizasyon problemi çözülmüştür. Bu sezgisel yöntem 69 baralı test sistemine ve 229 baralı gerçek bir sisteme jeneratör yerleştirmek için kullanılmıştır.
Demand Side Management; a New Opportunity for Energy Efficient Data Centers
Artan enerji ihtiyacı ve kısıtlı kaynaklar sürdürülebilir enerji kaynaklarına olan ilgiyi artırmı... more Artan enerji ihtiyacı ve kısıtlı kaynaklar sürdürülebilir enerji kaynaklarına olan ilgiyi artırmıştır. Güneş pili hücresi, rüzgar türbini, yakıt pili ve hidro türbin gibi sürdürülebilir ve çevreye zararsız enerji teknolojileri sıklıkla kullanılmaya başlanmıştır. Son yıllarda şebekeye gömülü kaynaklar entegre etmeye yönelik çalışmalar artmış ve yenilenebilir teknolojiler bu çalışmalara dahil edilmiştir. Elektrik enerji şebekesinde bunlara dağıtık jeneratör ya da yerel elektrik santralleri denmektedir. Yerel elektrik santralleri sistemin kayıplarını azaltırken, gerilim profilini iyileştirip sistemin güvenilirliğini artırmaktadır. Bu avantajlardan yararlanmak için yerel elektrik santrallerinin sisteme uygun yerde ve uygun boyutta yerleştirilmesi gerekir. Bu çalışmada Yapay Arı Kolonisi Algoritması kullanılarak lineer olmayan bu optimizasyon problemi çözülmüştür. Bu sezgisel yöntem 69 baralı test sistemine ve 229 baralı gerçek bir sisteme jeneratör yerleştirmek için kullanılmıştır.
Distribution network risk assessment in the presence of RES and ESS
2021 11th Smart Grid Conference (SGC), 2021
Information Systems Management, 2020
He received a Ph D degree in Management Engineering at KAIST. His research interests include gree... more He received a Ph D degree in Management Engineering at KAIST. His research interests include green information systems, computational social science, and virtual communities.
Distribution network risk assessment in the presence of RES and ESS
2021 11th Smart Grid Conference (SGC), 2021
Information Systems Management, 2020
He received a Ph D degree in Management Engineering at KAIST. His research interests include gree... more He received a Ph D degree in Management Engineering at KAIST. His research interests include green information systems, computational social science, and virtual communities.
Forecasting Data Centre Power Consumption with Artificial Neural Network Method and Designing Simulator User Interface
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Papers by Mehmet Hakan Hocaoglu
Güç sistemlerinde aşırı akım koruma pratiği, mesafe koruma pratiğinden daha ekonomik ve yaygındır. Ayrıca dağıtım şebekelerinin büyük bir çoğunluğunda aşırı akım koruma kullanılmaktadır. Bu durum, dağıtım şebekelerinde kullanılan aşırı akım rölelerin koordinasyonun en uygun şekilde tasarlanmasını gerekli kılmaktadır. Aksi halde sistemde gerçekleşen bir arıza sırasında röleler istenildiği gibi çalışamaz. Aşırı akım röleleri arasında koordinasyonun etkili ve seçici olabilmesi için röle ayar parametrelerinin şebekeye uygun ayarlanması gerekmektedir. Dağıtım şebekelerinin genişlemesi ile birlikte röle ayarlarının hesaplanması veya güncellenmesi zorlaşmıştır. Bu nedenle aşırı akım röle koordinasyonu yüksek sayıda kısıt içeren optimizasyon problemi şeklinde kurgulanmaktadır. Optimizasyon problemini çözümü noktasında ise peç çok meta-sezgisel algoritmalar geliştirilmiştir. Bu çalışmada IEEE 8 Baralı test şebekesi için Bozkurt Optimizasyon Algoritması (BOA) başarılı bir şekilde uygulanmış ve kapsamlı performans analizi gerçekleştirilmiştir.