Pub Date : 2020-10-19DOI: 10.1109/EPE51172.2020.9269205
L. Kukačka, J. Nečásek, M. Novák
The paper presents a numerical model of a Static Var Compensator (SVC). The model is suitable for simulating transients caused by switching the SVC module to the grid. The objective is to allow comparison of various SVC topologies during the design stage of SVC development and to verify that the operating conditions of the thyristors, capacitor and inductor stay within limits specified by the manufacturer. The model is verified against laboratory measurements. Simulation results for several SVC topologies are presented and discussed.
{"title":"Numerical Environment for Modeling and Analyzing Transients in Static VAR Compensators","authors":"L. Kukačka, J. Nečásek, M. Novák","doi":"10.1109/EPE51172.2020.9269205","DOIUrl":"https://doi.org/10.1109/EPE51172.2020.9269205","url":null,"abstract":"The paper presents a numerical model of a Static Var Compensator (SVC). The model is suitable for simulating transients caused by switching the SVC module to the grid. The objective is to allow comparison of various SVC topologies during the design stage of SVC development and to verify that the operating conditions of the thyristors, capacitor and inductor stay within limits specified by the manufacturer. The model is verified against laboratory measurements. Simulation results for several SVC topologies are presented and discussed.","PeriodicalId":177031,"journal":{"name":"2020 21st International Scientific Conference on Electric Power Engineering (EPE)","volume":"08 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125749701","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}
Pub Date : 2020-10-19DOI: 10.1109/EPE51172.2020.9269254
L. Frybortova, J. Rataj, L. Sklenka, J. Frybort, Filip Fejt, O. Novak
The training reactor VR-1 is a nuclear facility operated by Czech Technical University in Prague (CTU in Prague). It is a zero power reactor utilised mainly for the education and training and more than 25 experiments at multiple levels of difficulty are offered. The reactor is firmly connected in the international organizations and has the highest reputation for the training performance. In December 2020, the reactor will achieve 30 years of its successful operation. The anniversary is a good opportunity for a thorough retrospective of such a unique facility. History of the VR-1 reactor operation can be used as an inspiration for other operators of similar nuclear facilities.
{"title":"The Training Reactor VR-1 - 30 Years of Operation","authors":"L. Frybortova, J. Rataj, L. Sklenka, J. Frybort, Filip Fejt, O. Novak","doi":"10.1109/EPE51172.2020.9269254","DOIUrl":"https://doi.org/10.1109/EPE51172.2020.9269254","url":null,"abstract":"The training reactor VR-1 is a nuclear facility operated by Czech Technical University in Prague (CTU in Prague). It is a zero power reactor utilised mainly for the education and training and more than 25 experiments at multiple levels of difficulty are offered. The reactor is firmly connected in the international organizations and has the highest reputation for the training performance. In December 2020, the reactor will achieve 30 years of its successful operation. The anniversary is a good opportunity for a thorough retrospective of such a unique facility. History of the VR-1 reactor operation can be used as an inspiration for other operators of similar nuclear facilities.","PeriodicalId":177031,"journal":{"name":"2020 21st International Scientific Conference on Electric Power Engineering (EPE)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129024490","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}
Pub Date : 2020-10-19DOI: 10.1109/EPE51172.2020.9269228
Ondřej Šť astný, D. Král, Kamil Števanka, K. Katovský, A. Krása
The purpose of this study is to provide data for optimization of an experimental campaign that is under preparation within the frame of the ADAR project (Accelerator Driven Advanced Reactor with molten chloride salt fuel coolant). This article presents results of theoretical investigation of fast neutron field behavior in chloride salt environment. Non-fueled salt coolant (NaCl, KCl, MgCl2) as well as subcritical fuel-containing (PuCl3) one were considered. As an external neutron source, the radio-isotope AmBe source was modelled. Monte Carlo calculations were performed using the MCNP6.2 code with the ENDF/B-VIII.0 and JEFF-3.3 nuclear data libraries.
{"title":"Monte Carlo Calculations of Fast Neutron Transport in Chloride Salts","authors":"Ondřej Šť astný, D. Král, Kamil Števanka, K. Katovský, A. Krása","doi":"10.1109/EPE51172.2020.9269228","DOIUrl":"https://doi.org/10.1109/EPE51172.2020.9269228","url":null,"abstract":"The purpose of this study is to provide data for optimization of an experimental campaign that is under preparation within the frame of the ADAR project (Accelerator Driven Advanced Reactor with molten chloride salt fuel coolant). This article presents results of theoretical investigation of fast neutron field behavior in chloride salt environment. Non-fueled salt coolant (NaCl, KCl, MgCl2) as well as subcritical fuel-containing (PuCl3) one were considered. As an external neutron source, the radio-isotope AmBe source was modelled. Monte Carlo calculations were performed using the MCNP6.2 code with the ENDF/B-VIII.0 and JEFF-3.3 nuclear data libraries.","PeriodicalId":177031,"journal":{"name":"2020 21st International Scientific Conference on Electric Power Engineering (EPE)","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127879821","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}
Pub Date : 2020-10-19DOI: 10.1109/EPE51172.2020.9269227
M. Pourakbari‐Kasmaei, M. Lehtonen, F. Mahmood, Michal Krbal, Luděk Pelikán, J. Orságová, P. Toman
This paper develops an optimization model to find the optimal values for the parameters of the double-exponential function. This function can be used to reproduce the volt-time curves of the standard and nonstandard applied impulse voltages in a software environment. Reproducing a similar applied laboratory impulse voltage in a software environment plays a crucial role in obtaining precise results and validates the model to be applied for further studies. In the literature, most of the papers use the existing standard and nonstandard models in which either an RC circuit has been used or a trial and error method has been used to approximately reproduce the applied impulse. However, more often than not, inappropriate adjustments cause a large error in the outcome results. Therefore, the proposed optimization-based approach can act as a facilitating tool for reproducing the nonstandard volt-time curves as close as possible to the laboratory applied impulse. The proposed model is verified by reproducing the volt-time curve of a 125 kV impulse voltage. Comparing the simulated impulse with the experimental impulse voltage shows the usefulness and effectiveness of the proposed approach in adjusting the sensitive parameters of the double-exponential function in EMTP-RV (Electromagnetic Transients Program) software.
{"title":"Optimal Adjustment of Double Exponential Model Parameters to Reproduce the Laboratory Volt-Time Curve of Lightning Impulse","authors":"M. Pourakbari‐Kasmaei, M. Lehtonen, F. Mahmood, Michal Krbal, Luděk Pelikán, J. Orságová, P. Toman","doi":"10.1109/EPE51172.2020.9269227","DOIUrl":"https://doi.org/10.1109/EPE51172.2020.9269227","url":null,"abstract":"This paper develops an optimization model to find the optimal values for the parameters of the double-exponential function. This function can be used to reproduce the volt-time curves of the standard and nonstandard applied impulse voltages in a software environment. Reproducing a similar applied laboratory impulse voltage in a software environment plays a crucial role in obtaining precise results and validates the model to be applied for further studies. In the literature, most of the papers use the existing standard and nonstandard models in which either an RC circuit has been used or a trial and error method has been used to approximately reproduce the applied impulse. However, more often than not, inappropriate adjustments cause a large error in the outcome results. Therefore, the proposed optimization-based approach can act as a facilitating tool for reproducing the nonstandard volt-time curves as close as possible to the laboratory applied impulse. The proposed model is verified by reproducing the volt-time curve of a 125 kV impulse voltage. Comparing the simulated impulse with the experimental impulse voltage shows the usefulness and effectiveness of the proposed approach in adjusting the sensitive parameters of the double-exponential function in EMTP-RV (Electromagnetic Transients Program) software.","PeriodicalId":177031,"journal":{"name":"2020 21st International Scientific Conference on Electric Power Engineering (EPE)","volume":"2012 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121463411","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}
Pub Date : 2020-10-19DOI: 10.1109/EPE51172.2020.9269171
Ondřej Kabot, J. Fulneček, S. Mišák, L. Prokop, J. Vaculík
Covered conductors represents an alternative to the reinforced aluminum conductors. The E.ON Distribuce company aims to replace some of the reinforced aluminum conductors in its overhead distribution network with covered conductors. To make this distribution network as reliable as possible, the overhead powerlines will be equipped with online insulation fault detector. Problematic insulation fault detection is one of the biggest disadvantages of medium voltage covered conductors, because of the very low fault current. But during this type of faults, partial discharges activity is usually presented. Based on this knowledge, on-line partial discharges monitor was deigned at VSB – TUO to detect such insulation faults on medium voltage overhead power lines. This article describes the testing of various covered conductors from the point of partial discharge activity during high impedance faults.
{"title":"Partial Discharges Pattern Analysis of Various Covered Conductors","authors":"Ondřej Kabot, J. Fulneček, S. Mišák, L. Prokop, J. Vaculík","doi":"10.1109/EPE51172.2020.9269171","DOIUrl":"https://doi.org/10.1109/EPE51172.2020.9269171","url":null,"abstract":"Covered conductors represents an alternative to the reinforced aluminum conductors. The E.ON Distribuce company aims to replace some of the reinforced aluminum conductors in its overhead distribution network with covered conductors. To make this distribution network as reliable as possible, the overhead powerlines will be equipped with online insulation fault detector. Problematic insulation fault detection is one of the biggest disadvantages of medium voltage covered conductors, because of the very low fault current. But during this type of faults, partial discharges activity is usually presented. Based on this knowledge, on-line partial discharges monitor was deigned at VSB – TUO to detect such insulation faults on medium voltage overhead power lines. This article describes the testing of various covered conductors from the point of partial discharge activity during high impedance faults.","PeriodicalId":177031,"journal":{"name":"2020 21st International Scientific Conference on Electric Power Engineering (EPE)","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132643452","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}
Pub Date : 2020-10-19DOI: 10.1109/EPE51172.2020.9269187
P. Šimek, V. Valouch
The aim of the paper is to present a power control of a three-phase inverter with only four inverter legs (connections B4) connected to an unbalanced grid. The results obtained by the predictive power control with a finite set of control values, the results obtained using a modified direct power control strategy, and the results obtained using a generalized predictive control are compared and discussed.
{"title":"Comparison of power control method for B4 converter connected to unbalanced grid","authors":"P. Šimek, V. Valouch","doi":"10.1109/EPE51172.2020.9269187","DOIUrl":"https://doi.org/10.1109/EPE51172.2020.9269187","url":null,"abstract":"The aim of the paper is to present a power control of a three-phase inverter with only four inverter legs (connections B4) connected to an unbalanced grid. The results obtained by the predictive power control with a finite set of control values, the results obtained using a modified direct power control strategy, and the results obtained using a generalized predictive control are compared and discussed.","PeriodicalId":177031,"journal":{"name":"2020 21st International Scientific Conference on Electric Power Engineering (EPE)","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131456162","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}
Pub Date : 2020-10-19DOI: 10.1109/EPE51172.2020.9269172
J. Zich, J. Jandík
The home battery energy storage systems (ESSs) are expanding worldwide together with the renewable energy sources (especially solar power plants). As the energy sourced by the different power sources (sun, wind, electrical grid) has to be stored inside the ESS the electrochemical cells (batteries) are usually used. The key parameters of the individual cells (internal resistance, capacity etc.) may differ significantly due to the manufacturing tolerances and also the operating conditions (temperature, load current) affect the current state of the individual cells. Therefore, the state of charge and open cell voltage are unbalanced. In order to prolong the battery life time, ensure the device safety and monitor the voltage and energy levels of each cell the active battery monitoring system (BMS) is a necessity. This paper describes mainly the hardware architecture of the complex BMS allowing the user to monitor the exact values of the actual cell voltage levels, temperatures in the battery modules and many status information concerning the BMS and cell health status.
{"title":"Active Battery Management System for Home Battery Energy Storage","authors":"J. Zich, J. Jandík","doi":"10.1109/EPE51172.2020.9269172","DOIUrl":"https://doi.org/10.1109/EPE51172.2020.9269172","url":null,"abstract":"The home battery energy storage systems (ESSs) are expanding worldwide together with the renewable energy sources (especially solar power plants). As the energy sourced by the different power sources (sun, wind, electrical grid) has to be stored inside the ESS the electrochemical cells (batteries) are usually used. The key parameters of the individual cells (internal resistance, capacity etc.) may differ significantly due to the manufacturing tolerances and also the operating conditions (temperature, load current) affect the current state of the individual cells. Therefore, the state of charge and open cell voltage are unbalanced. In order to prolong the battery life time, ensure the device safety and monitor the voltage and energy levels of each cell the active battery monitoring system (BMS) is a necessity. This paper describes mainly the hardware architecture of the complex BMS allowing the user to monitor the exact values of the actual cell voltage levels, temperatures in the battery modules and many status information concerning the BMS and cell health status.","PeriodicalId":177031,"journal":{"name":"2020 21st International Scientific Conference on Electric Power Engineering (EPE)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130726583","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}
Pub Date : 2020-10-19DOI: 10.1109/EPE51172.2020.9269208
P. Skarolek, J. Lettl
This paper presents a comparison of three different transistor technologies Silicon Superjunction (Si SJ), Silicon Carbide (SiC) and Gallium Nitride (GaN) in respect to deadtime setting in a typical halfbridge converter. According to the measured results both new fast switching transistors SiC and GaN needs precise deadtime setting compared to the Si SJ devices. With wrong deadtime settings the converter efficiency drops more rapidly for GaN compared to SiC while the Si SJ device is the least affected by the deadtime length. The optimum deadtime in DC/DC converter can be found by tracking the maximum output voltage for given constant and compensated duty cycle and input voltage.
{"title":"Influence of Deadtime on Si, SiC and GaN Converters","authors":"P. Skarolek, J. Lettl","doi":"10.1109/EPE51172.2020.9269208","DOIUrl":"https://doi.org/10.1109/EPE51172.2020.9269208","url":null,"abstract":"This paper presents a comparison of three different transistor technologies Silicon Superjunction (Si SJ), Silicon Carbide (SiC) and Gallium Nitride (GaN) in respect to deadtime setting in a typical halfbridge converter. According to the measured results both new fast switching transistors SiC and GaN needs precise deadtime setting compared to the Si SJ devices. With wrong deadtime settings the converter efficiency drops more rapidly for GaN compared to SiC while the Si SJ device is the least affected by the deadtime length. The optimum deadtime in DC/DC converter can be found by tracking the maximum output voltage for given constant and compensated duty cycle and input voltage.","PeriodicalId":177031,"journal":{"name":"2020 21st International Scientific Conference on Electric Power Engineering (EPE)","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117184635","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}
Pub Date : 2020-10-19DOI: 10.1109/EPE51172.2020.9269214
A. Alshammari, M. Čerňan, Z. Müller
Efficiency of electricity systems is currently a high priority for the society. Our article focuses on the area of low voltage distribution system, where we focus more deeply on the possibilities of reducing technical losses. To achieve this goal, many traditional methods are known which require modification and intervention in the distribution system. Our concept is based on the possibility of reducing active losses using small photovoltaic systems installed at low voltage customers. For this purpose, a low voltage feeder model of the corresponding structure was created in this work. Using this model, a case study based on real data (solar irradiation data and typical daily diagrams of low voltage customers) was performed. The results of the simulations show considerable potential for reducing technical losses using the described concept.
{"title":"Potential of Technical Losses Reduction in Low Voltage Feeder Using Small Photovoltaics","authors":"A. Alshammari, M. Čerňan, Z. Müller","doi":"10.1109/EPE51172.2020.9269214","DOIUrl":"https://doi.org/10.1109/EPE51172.2020.9269214","url":null,"abstract":"Efficiency of electricity systems is currently a high priority for the society. Our article focuses on the area of low voltage distribution system, where we focus more deeply on the possibilities of reducing technical losses. To achieve this goal, many traditional methods are known which require modification and intervention in the distribution system. Our concept is based on the possibility of reducing active losses using small photovoltaic systems installed at low voltage customers. For this purpose, a low voltage feeder model of the corresponding structure was created in this work. Using this model, a case study based on real data (solar irradiation data and typical daily diagrams of low voltage customers) was performed. The results of the simulations show considerable potential for reducing technical losses using the described concept.","PeriodicalId":177031,"journal":{"name":"2020 21st International Scientific Conference on Electric Power Engineering (EPE)","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115380574","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}
Pub Date : 2020-10-19DOI: 10.1109/EPE51172.2020.9269219
V. Krcal, D. Topolanek
This paper is focused on calculation of negative sequence changes of voltage and current from distributed measurement. These changes are necessary for evaluation of a new fault localization method Vdip. A principle of changes calculation is described, and problems affiliated with phasor estimation are discussed. Solutions for suppressing major disturbances, such as frequency deviation and interharmonics, are suggested. A way of cancelling out interharmonics based on averaging in sliding windows is presented. Eventually, a calculation procedure is formed, and performance of individual proceedings is tested. The analysis shows that optimized setting of time frames, from which the changes are calculated, is essential to mitigate negative impacts of the major interharmonic frequencies, and can substitute utilization of digital filtering.
{"title":"Negative Sequence Changes Calculation for Purposes of Fault Localization","authors":"V. Krcal, D. Topolanek","doi":"10.1109/EPE51172.2020.9269219","DOIUrl":"https://doi.org/10.1109/EPE51172.2020.9269219","url":null,"abstract":"This paper is focused on calculation of negative sequence changes of voltage and current from distributed measurement. These changes are necessary for evaluation of a new fault localization method Vdip. A principle of changes calculation is described, and problems affiliated with phasor estimation are discussed. Solutions for suppressing major disturbances, such as frequency deviation and interharmonics, are suggested. A way of cancelling out interharmonics based on averaging in sliding windows is presented. Eventually, a calculation procedure is formed, and performance of individual proceedings is tested. The analysis shows that optimized setting of time frames, from which the changes are calculated, is essential to mitigate negative impacts of the major interharmonic frequencies, and can substitute utilization of digital filtering.","PeriodicalId":177031,"journal":{"name":"2020 21st International Scientific Conference on Electric Power Engineering (EPE)","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129900232","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：