Abstract After the separation of the Continental Europe power system on 8th January 2021 in two synchronous zones, the electric power system of BiH (EPS BiH) shows a significant increase in frequency and voltages and oscillations of active and reactive power. The paper discusses the operation of protective devices in the BiH power system when the system was operating at high frequencies and voltages and had oscillations of active and reactive power. As a consequence of this behaviour in the EPS BiH there was activation of distance protections (DP) in substation (SS) 220/110 kV Prijedor 2 and overhead transmission lines (OHL) 220 kV Prijedor 2 - Međurić and OHL 220 kV Prijedor 2 – Sisak were disconnected. This was followed by activation of generator protections (reverse power protection and under-excitation protection) and outages of generator units in Hydro Power Plant (HPP) Salakovac, Thermal Power Plant (TPP) Kakanj, HPP Mostar, HPP Bočac, HPP Peć Mlini and HPP Jajce 2.
{"title":"Impact of the Separation of the Continental Europe Power System on January 8, 2021 on the Work of the Bosnia and Herzegovina Power System","authors":"Husnija Ferizović, Branislav Koprena","doi":"10.2478/bhee-2022-0002","DOIUrl":"https://doi.org/10.2478/bhee-2022-0002","url":null,"abstract":"Abstract After the separation of the Continental Europe power system on 8th January 2021 in two synchronous zones, the electric power system of BiH (EPS BiH) shows a significant increase in frequency and voltages and oscillations of active and reactive power. The paper discusses the operation of protective devices in the BiH power system when the system was operating at high frequencies and voltages and had oscillations of active and reactive power. As a consequence of this behaviour in the EPS BiH there was activation of distance protections (DP) in substation (SS) 220/110 kV Prijedor 2 and overhead transmission lines (OHL) 220 kV Prijedor 2 - Međurić and OHL 220 kV Prijedor 2 – Sisak were disconnected. This was followed by activation of generator protections (reverse power protection and under-excitation protection) and outages of generator units in Hydro Power Plant (HPP) Salakovac, Thermal Power Plant (TPP) Kakanj, HPP Mostar, HPP Bočac, HPP Peć Mlini and HPP Jajce 2.","PeriodicalId":236883,"journal":{"name":"B&H Electrical Engineering","volume":"146 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134452277","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Artificial intelligence (AI) and Deep learning (DL) methods in power systems are being tested and prepared for practical use in many applications. In this work an artificial neural network models for fault identification and classification and switching logic control in middle voltage (MV) power electricity network is presented. Models are implemented in Google’s Python based tool Tensorflow with belonging program libraries. For fault detection and classification example a few thousand simulations are conducted in order to obtain enough fault current and voltage samples for high accuracy artificial neural network (ANN) with backpropagation model. Achieved accuracy and speed of presented deep learning model, open a possibility for application in digital relay protection devices. Second example is implementation of switching control rules in HV/MV substations. Presented models are patterns for power system controlling centres as part of broader controlling and protection logic.
{"title":"Power System Control and Protection Models Based on Artificial Intelligence – A Tensorflow Approach","authors":"A. Bernadic","doi":"10.2478/bhee-2022-0004","DOIUrl":"https://doi.org/10.2478/bhee-2022-0004","url":null,"abstract":"Abstract Artificial intelligence (AI) and Deep learning (DL) methods in power systems are being tested and prepared for practical use in many applications. In this work an artificial neural network models for fault identification and classification and switching logic control in middle voltage (MV) power electricity network is presented. Models are implemented in Google’s Python based tool Tensorflow with belonging program libraries. For fault detection and classification example a few thousand simulations are conducted in order to obtain enough fault current and voltage samples for high accuracy artificial neural network (ANN) with backpropagation model. Achieved accuracy and speed of presented deep learning model, open a possibility for application in digital relay protection devices. Second example is implementation of switching control rules in HV/MV substations. Presented models are patterns for power system controlling centres as part of broader controlling and protection logic.","PeriodicalId":236883,"journal":{"name":"B&H Electrical Engineering","volume":"132 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114415385","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Considering that the need for electricity is constantly increasing, a crucial problem is the lack of new power facilities. Likewise, due to the large expansion of existing consumption, one of the primary tasks is the reconstruction of existing facilities. Due to their complexity, such problems cannot be solved unplanned, but the development of adequate system solutions must be planned. The biggest problem in finding such solutions is matching both companies and consumers needs. The best way to do this is to develop mathematical models that can meet the already mentioned needs. The development of such models is not a simple task, considering that the final solution is influenced by a number of factors, many of which have a random nature. Therefore, the use of stochastic optimization methods is imposed as a realistic basis for the development of such models, as it is the case in the model presented in this paper. Considering that voltage unbalance is one of the mentioned influential factors, this paper will give the answer to the question whether it has a significant impact on the final solution of the developed model.
{"title":"Influence of Voltage Unbalance on the Solution of One Planning Model of Low-Voltage Distribution Networks","authors":"A. Softić, H. Salkić, M. Stojkov","doi":"10.2478/bhee-2022-0003","DOIUrl":"https://doi.org/10.2478/bhee-2022-0003","url":null,"abstract":"Abstract Considering that the need for electricity is constantly increasing, a crucial problem is the lack of new power facilities. Likewise, due to the large expansion of existing consumption, one of the primary tasks is the reconstruction of existing facilities. Due to their complexity, such problems cannot be solved unplanned, but the development of adequate system solutions must be planned. The biggest problem in finding such solutions is matching both companies and consumers needs. The best way to do this is to develop mathematical models that can meet the already mentioned needs. The development of such models is not a simple task, considering that the final solution is influenced by a number of factors, many of which have a random nature. Therefore, the use of stochastic optimization methods is imposed as a realistic basis for the development of such models, as it is the case in the model presented in this paper. Considering that voltage unbalance is one of the mentioned influential factors, this paper will give the answer to the question whether it has a significant impact on the final solution of the developed model.","PeriodicalId":236883,"journal":{"name":"B&H Electrical Engineering","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129003121","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Muris Bakalović, Merim Džizić, Dženeta Erović, Mario Šeremet
Abstract Settlement of unintended deviation between scheduled and realized energy exchange among LFC (Load Frequency Control) areas used to be conducted through the energy compensation programs, where energy deviation from period of registration is compensated at a later stage period of compensation of unintended deviation. With the adoption of the Synchronous Area Framework Agreement (SAFA), the Regional Group for Continental Europe the methodology of accounting and financial settlement of unintended deviations FSKAR (Financial settlement kΔf, ACE and ramping period) is defined. The FSKAR methodology defines necessary data for the calculation and determination of unintended deviation. The methodology defines the method of determining settlement prices. The paper describes the methodology of determining settlement prices, the method of data collection and validation, the method of calculation of deviations and other energy and financial quantities, and data exchange between entities.
{"title":"Introduction of Financial Settlement Among LFC Areas","authors":"Muris Bakalović, Merim Džizić, Dženeta Erović, Mario Šeremet","doi":"10.2478/bhee-2022-0005","DOIUrl":"https://doi.org/10.2478/bhee-2022-0005","url":null,"abstract":"Abstract Settlement of unintended deviation between scheduled and realized energy exchange among LFC (Load Frequency Control) areas used to be conducted through the energy compensation programs, where energy deviation from period of registration is compensated at a later stage period of compensation of unintended deviation. With the adoption of the Synchronous Area Framework Agreement (SAFA), the Regional Group for Continental Europe the methodology of accounting and financial settlement of unintended deviations FSKAR (Financial settlement kΔf, ACE and ramping period) is defined. The FSKAR methodology defines necessary data for the calculation and determination of unintended deviation. The methodology defines the method of determining settlement prices. The paper describes the methodology of determining settlement prices, the method of data collection and validation, the method of calculation of deviations and other energy and financial quantities, and data exchange between entities.","PeriodicalId":236883,"journal":{"name":"B&H Electrical Engineering","volume":"224 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130709158","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract A low impedance fault on a transmission line causes large fault currents that can lead current transformers in the switchyard that supplies the fault to saturation. If the fast automatic reclosing is implemented the current transformers additionally enter saturation. After the definitive trip, the residual magnetic energy in the current transformers is discharged via secondary circuits. The measuring inputs of the protective devices are connected to the secondary of the current transformers, and if the current is large and lasts long enough consequence can be an unwanted operation of the protective device. This paper gives an example of an unwanted operation of circuit breaker failure protection, which is a function within distributed busbar protection, as a consequence of such an event.
{"title":"Influence of Current Transformer Saturation on Numerical Protection Relays – A Case Study of Circuit Breaker Failure Protection","authors":"Sead Arnautalić, Ebedija Hajder Mujčinagić, Srđan Petrović","doi":"10.2478/bhee-2021-0021","DOIUrl":"https://doi.org/10.2478/bhee-2021-0021","url":null,"abstract":"Abstract A low impedance fault on a transmission line causes large fault currents that can lead current transformers in the switchyard that supplies the fault to saturation. If the fast automatic reclosing is implemented the current transformers additionally enter saturation. After the definitive trip, the residual magnetic energy in the current transformers is discharged via secondary circuits. The measuring inputs of the protective devices are connected to the secondary of the current transformers, and if the current is large and lasts long enough consequence can be an unwanted operation of the protective device. This paper gives an example of an unwanted operation of circuit breaker failure protection, which is a function within distributed busbar protection, as a consequence of such an event.","PeriodicalId":236883,"journal":{"name":"B&H Electrical Engineering","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121858256","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Increasing the energy efficiency of electricity distribution networks is the commitment of all national and private electricity distribution companies. One of the basic goals is to reduce losses in electricity distribution networks. It is known that losses in the distribution network can be defined as the differences between taken and delivered electricity. Determining losses has several basic tasks. The first task is to determine the difference between the calculated losses and the actual losses, and to determine the reason for this difference and to determine the necessary guidelines for taking measures to reduce losses. The second task is to estimate the loss index for planning and formulating different plans. This paper presents a new approach to reduce the error between calculated and actual losses using a new method based on the Three Mode method. The main purpose of the study was to investigate the power losses in distribution area. The method proposed in this paper significantly reduces the error compared to the classical Three modes method, which is the original contribution of this paper.
{"title":"Estimation of Electricity Losses in Distributed Electricity Network Using an Improved Three Mode Method","authors":"Emir Alibašić, Z. Baus, Maja Muftić-Dedović","doi":"10.2478/bhee-2021-0016","DOIUrl":"https://doi.org/10.2478/bhee-2021-0016","url":null,"abstract":"Abstract Increasing the energy efficiency of electricity distribution networks is the commitment of all national and private electricity distribution companies. One of the basic goals is to reduce losses in electricity distribution networks. It is known that losses in the distribution network can be defined as the differences between taken and delivered electricity. Determining losses has several basic tasks. The first task is to determine the difference between the calculated losses and the actual losses, and to determine the reason for this difference and to determine the necessary guidelines for taking measures to reduce losses. The second task is to estimate the loss index for planning and formulating different plans. This paper presents a new approach to reduce the error between calculated and actual losses using a new method based on the Three Mode method. The main purpose of the study was to investigate the power losses in distribution area. The method proposed in this paper significantly reduces the error compared to the classical Three modes method, which is the original contribution of this paper.","PeriodicalId":236883,"journal":{"name":"B&H Electrical Engineering","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134222853","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Senad Hadžić, Husnija Ferizović, Obrad Skrba, A. Muharemovic, Bojan Rebić
Abstract The paper presents the results of testing the operational capabilities of the pump hydropower plant (PHPP) Capljina in compensatory, under excited mode in real time, and answers the questions how, and to what extent, the operation of PHPP Capljina in the under excited mode affects the improvement of voltage conditions in the power system of B&H. The test was performed with one machine in compensatory under excited mode with the takeover of reactive power in the amount of 160 MVAr, in a period of 4 hours. During the test, thermal power plant (TPP) Gacko operated in the maximum under excited mode for a certain period of time.
{"title":"The Influence of Compensatory Regime of Operation of Pump Hydropower Plant Capljina on Voltage Conditions in Electric Power System of Bosnia and Herzegovina","authors":"Senad Hadžić, Husnija Ferizović, Obrad Skrba, A. Muharemovic, Bojan Rebić","doi":"10.2478/bhee-2021-0022","DOIUrl":"https://doi.org/10.2478/bhee-2021-0022","url":null,"abstract":"Abstract The paper presents the results of testing the operational capabilities of the pump hydropower plant (PHPP) Capljina in compensatory, under excited mode in real time, and answers the questions how, and to what extent, the operation of PHPP Capljina in the under excited mode affects the improvement of voltage conditions in the power system of B&H. The test was performed with one machine in compensatory under excited mode with the takeover of reactive power in the amount of 160 MVAr, in a period of 4 hours. During the test, thermal power plant (TPP) Gacko operated in the maximum under excited mode for a certain period of time.","PeriodicalId":236883,"journal":{"name":"B&H Electrical Engineering","volume":"123 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123938591","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract In the process of designing a system, it is necessary to identify potential threats to that system and to include appropriate countermeasures. The process that helps in finding problems in the initial phase of the system design is the threat modeling. Creating a threat model consists of several steps and there are many tools that can help in automating the procedure. This article deals with the threat analysis for an Ambient Assisted Living (AAL) system based on Wireless Sensor Network (WSN), whose main function is to provide information for carers in order to provide the best possible help to the elderly and disabled. We have identified and analysed 99 potential threats to the considered system, where Denial of Service (DoS) resulted in being the most represented class of threats. After conducting the threat assessment, the obtained results showed that the majority of threats are high-risk and justified the use of threat modeling in the design phase, since they can be utilized in further system development stages.
{"title":"Analysis of Threats for Ambient Assisted Living (AAL) Wireless Sensor Network (WSN)-Based System","authors":"Nejla Popaja, Sabina Baraković, J. Husić","doi":"10.2478/bhee-2021-0015","DOIUrl":"https://doi.org/10.2478/bhee-2021-0015","url":null,"abstract":"Abstract In the process of designing a system, it is necessary to identify potential threats to that system and to include appropriate countermeasures. The process that helps in finding problems in the initial phase of the system design is the threat modeling. Creating a threat model consists of several steps and there are many tools that can help in automating the procedure. This article deals with the threat analysis for an Ambient Assisted Living (AAL) system based on Wireless Sensor Network (WSN), whose main function is to provide information for carers in order to provide the best possible help to the elderly and disabled. We have identified and analysed 99 potential threats to the considered system, where Denial of Service (DoS) resulted in being the most represented class of threats. After conducting the threat assessment, the obtained results showed that the majority of threats are high-risk and justified the use of threat modeling in the design phase, since they can be utilized in further system development stages.","PeriodicalId":236883,"journal":{"name":"B&H Electrical Engineering","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129276989","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract The security of using applications in cloud services and on the Internet is an important topic in the field of engineering. In this paper, two laboratory tests for data transmission protection, specifically designed for different security analysis techniques, are presented and explained. During lab tests on public Wi-Fi networks from the MIDM (“Man in the Middle”) attacks, various monitoring techniques were applied, using a special lab test scenario with Kali Linux penetration tools by creating an SSH tunnel on an Android mobile device. These test benches allow easy data capturing, and the captured data is processed using available software programs. Expected outcomes, practical improvement and security performance assessment are presented in detail, and considered in terms of their value in security engineering. The aim of this paper is to detect and overcome some of the weaknesses of the application of security protocols in a Wi-Fi network environment.
{"title":"Testing the Data Protection Through Implementation of Secure Communication","authors":"S. Kasapovic, Emir Skejic, Tarik Huremović","doi":"10.2478/bhee-2021-0014","DOIUrl":"https://doi.org/10.2478/bhee-2021-0014","url":null,"abstract":"Abstract The security of using applications in cloud services and on the Internet is an important topic in the field of engineering. In this paper, two laboratory tests for data transmission protection, specifically designed for different security analysis techniques, are presented and explained. During lab tests on public Wi-Fi networks from the MIDM (“Man in the Middle”) attacks, various monitoring techniques were applied, using a special lab test scenario with Kali Linux penetration tools by creating an SSH tunnel on an Android mobile device. These test benches allow easy data capturing, and the captured data is processed using available software programs. Expected outcomes, practical improvement and security performance assessment are presented in detail, and considered in terms of their value in security engineering. The aim of this paper is to detect and overcome some of the weaknesses of the application of security protocols in a Wi-Fi network environment.","PeriodicalId":236883,"journal":{"name":"B&H Electrical Engineering","volume":"116 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130551214","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract The paper describes the function and importance of safety devices on pressure equipment, legal regulations for the necessary scope and periods of functional inspections of safety valves in thermal power plants. The mode of operation of the apparatus for in-site testing and adjustment of safety valves on pressure vessels is described, as well as a comparative presentation of the obtained test results compared to the results obtained by the conventional method that uses hydraulic pressure of the medium for valve spring load. The on-site method uses a motor drive to load the valve spring, and uses sensitive displacement, force and sound sensors to generate signals, which are processed in a suitable software application to obtain test results. Unlike the conventional method, the on-site method allows testing of safety valves without their disassembly from the installation site. A comparison of the test results obtained by the modern method with the test results by the conventional method was made on several safety valves. It has been shown that in addition to better precision, which is important for valves with lower operating pressures, the application of the on-site method shortens the test time several times.
{"title":"On-Site Safety-Valves Testing in Thermal Power Plants","authors":"Kenan Kadić, Adem Lujnović, N. Hodžić, A. Kazagić","doi":"10.2478/bhee-2021-0020","DOIUrl":"https://doi.org/10.2478/bhee-2021-0020","url":null,"abstract":"Abstract The paper describes the function and importance of safety devices on pressure equipment, legal regulations for the necessary scope and periods of functional inspections of safety valves in thermal power plants. The mode of operation of the apparatus for in-site testing and adjustment of safety valves on pressure vessels is described, as well as a comparative presentation of the obtained test results compared to the results obtained by the conventional method that uses hydraulic pressure of the medium for valve spring load. The on-site method uses a motor drive to load the valve spring, and uses sensitive displacement, force and sound sensors to generate signals, which are processed in a suitable software application to obtain test results. Unlike the conventional method, the on-site method allows testing of safety valves without their disassembly from the installation site. A comparison of the test results obtained by the modern method with the test results by the conventional method was made on several safety valves. It has been shown that in addition to better precision, which is important for valves with lower operating pressures, the application of the on-site method shortens the test time several times.","PeriodicalId":236883,"journal":{"name":"B&H Electrical Engineering","volume":"119 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116616205","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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