Pub Date : 2022-11-17DOI: 10.1109/WCNPS56355.2022.9969692
Caio Muller S. Ribeiro, F. Lopes, K. M. e Silva
In this paper, traveling wave (TW) propagation velocity on HVDC systems is assessed. Most TW-based fault location methods consider that all wave-fronts travel throughout transmission lines at the same velocity. However, TW velocities change according to various factors, such as fault distance and line electrical parameters. In HVDC systems with long lengths, these velocities may significantly vary, leading the premise of equal velocities over the line to be no longer valid. To assess the TW propagation velocity on HVDC grids, controlled fault cases are carried out by means of Alternative Transients Program (ATP) simulations in a CIGRE benchmark model, which represents the Madeira River HVDC Bipolar System. The obtained results show that the TW velocities are affected by the fault distance, decreasing as they travel along the line. Moreover, it is demonstrated that the higher the soil resistivity, the lower the TW propagation velocity.
{"title":"Assessment of Traveling Wave Propagation Velocity on HVDC Transmission Lines","authors":"Caio Muller S. Ribeiro, F. Lopes, K. M. e Silva","doi":"10.1109/WCNPS56355.2022.9969692","DOIUrl":"https://doi.org/10.1109/WCNPS56355.2022.9969692","url":null,"abstract":"In this paper, traveling wave (TW) propagation velocity on HVDC systems is assessed. Most TW-based fault location methods consider that all wave-fronts travel throughout transmission lines at the same velocity. However, TW velocities change according to various factors, such as fault distance and line electrical parameters. In HVDC systems with long lengths, these velocities may significantly vary, leading the premise of equal velocities over the line to be no longer valid. To assess the TW propagation velocity on HVDC grids, controlled fault cases are carried out by means of Alternative Transients Program (ATP) simulations in a CIGRE benchmark model, which represents the Madeira River HVDC Bipolar System. The obtained results show that the TW velocities are affected by the fault distance, decreasing as they travel along the line. Moreover, it is demonstrated that the higher the soil resistivity, the lower the TW propagation velocity.","PeriodicalId":120276,"journal":{"name":"2022 Workshop on Communication Networks and Power Systems (WCNPS)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130924841","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 : 2022-11-17DOI: 10.1109/WCNPS56355.2022.9969740
C. M. Moraes, Marco A. de Brito Ribeiro, A. Martins-Britto
Due to long extensions involved, being exposed to the environment, and occupying large amounts of space, transmission lines (TLs) eventually interfere electromagnetically with other metallic structures. Electromagnetic interferences (EMIs) often generate risks to the safety of the installations and people involved. Realistic approaches to address EMI studies are often computationally intensive. Thus, simplified models that accurately represent real phenomena are very important. In this context, this paper determines the effective distance from the observation point in which the TLs tower grounding system can be replaced by a simplified point-source model. A hypothetical case of parallelism is performed to validate the proposed methodology. Results show that from a distance of three times the counterpoise conductors length, the simplified model can be used in several hypothetical scenarios of discrepancy. The results obtained using the effective distance and the simplified model presented a 2.89% discrepancy and an improvement of 11.77% in software performance.
{"title":"On the effective length of transmission line grounding conductors and the validity of the point-source model in GPR responses","authors":"C. M. Moraes, Marco A. de Brito Ribeiro, A. Martins-Britto","doi":"10.1109/WCNPS56355.2022.9969740","DOIUrl":"https://doi.org/10.1109/WCNPS56355.2022.9969740","url":null,"abstract":"Due to long extensions involved, being exposed to the environment, and occupying large amounts of space, transmission lines (TLs) eventually interfere electromagnetically with other metallic structures. Electromagnetic interferences (EMIs) often generate risks to the safety of the installations and people involved. Realistic approaches to address EMI studies are often computationally intensive. Thus, simplified models that accurately represent real phenomena are very important. In this context, this paper determines the effective distance from the observation point in which the TLs tower grounding system can be replaced by a simplified point-source model. A hypothetical case of parallelism is performed to validate the proposed methodology. Results show that from a distance of three times the counterpoise conductors length, the simplified model can be used in several hypothetical scenarios of discrepancy. The results obtained using the effective distance and the simplified model presented a 2.89% discrepancy and an improvement of 11.77% in software performance.","PeriodicalId":120276,"journal":{"name":"2022 Workshop on Communication Networks and Power Systems (WCNPS)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114169639","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 : 2022-11-17DOI: 10.1109/WCNPS56355.2022.9969699
F. Lopes, M.J.B.B. Davi, M. Oleskovicz, G. Fabris
This paper addresses the importance of Electromagnetic Transients (EMT)-type simulations for protection studies in power networks with inverterbased resources (IBRs). Firstly, real records taken from IBR interconnecting lines are analyzed to explain possible effects of transient events on phasor-based protection elements. Then, EMT-type simulations are carried out to demonstrate the impacts of IBRs on protection elements, which can be analyzed only via EMT programs (EMTP). Finally, since traveling wave (TW)-based solutions have been reported as promising alternatives to complement conventional protection schemes in the presence of IBRs, a list of system EMT modeling recommendations is presented to guarantee realistic TW studies in IBR interconnecting lines. The conclusions show that transient events in power systems with IBRs must be considered in protection studies, pointing out the importance of EMT-type simulations.
{"title":"Importance of EMT-Type Simulations for Protection Studies in Power Systems with Inverter-Based Resources","authors":"F. Lopes, M.J.B.B. Davi, M. Oleskovicz, G. Fabris","doi":"10.1109/WCNPS56355.2022.9969699","DOIUrl":"https://doi.org/10.1109/WCNPS56355.2022.9969699","url":null,"abstract":"This paper addresses the importance of Electromagnetic Transients (EMT)-type simulations for protection studies in power networks with inverterbased resources (IBRs). Firstly, real records taken from IBR interconnecting lines are analyzed to explain possible effects of transient events on phasor-based protection elements. Then, EMT-type simulations are carried out to demonstrate the impacts of IBRs on protection elements, which can be analyzed only via EMT programs (EMTP). Finally, since traveling wave (TW)-based solutions have been reported as promising alternatives to complement conventional protection schemes in the presence of IBRs, a list of system EMT modeling recommendations is presented to guarantee realistic TW studies in IBR interconnecting lines. The conclusions show that transient events in power systems with IBRs must be considered in protection studies, pointing out the importance of EMT-type simulations.","PeriodicalId":120276,"journal":{"name":"2022 Workshop on Communication Networks and Power Systems (WCNPS)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122183699","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 : 2022-11-17DOI: 10.1109/WCNPS56355.2022.9969756
T. F. Pascoalato, A. D. de Araújo, Sérgio Kurokawa, J. Filho
This paper investigates the impact of the improved Archie's model for soil resistivity considering the volumetric water content and porosity on the transient responses developed for energization and a lightning strike applied at only one phase of the line. In this study, an overhead transmission line located on saturated sandy soil modeled by different levels of volumetric water content and porosity was assumed. The transient responses were compared to those obtained adopting a high-resistivity dry sandy soil. Results have demonstrated that the transient voltages have a significant impact on the volumetric water content and porosity for this type of soil. The pronounced variation is seen in the induced voltages for both types of disturbances.
{"title":"Impact of Volumetric Water Content and Porosity on Transmission Lines Submitted to Energization and Lightning Strikes","authors":"T. F. Pascoalato, A. D. de Araújo, Sérgio Kurokawa, J. Filho","doi":"10.1109/WCNPS56355.2022.9969756","DOIUrl":"https://doi.org/10.1109/WCNPS56355.2022.9969756","url":null,"abstract":"This paper investigates the impact of the improved Archie's model for soil resistivity considering the volumetric water content and porosity on the transient responses developed for energization and a lightning strike applied at only one phase of the line. In this study, an overhead transmission line located on saturated sandy soil modeled by different levels of volumetric water content and porosity was assumed. The transient responses were compared to those obtained adopting a high-resistivity dry sandy soil. Results have demonstrated that the transient voltages have a significant impact on the volumetric water content and porosity for this type of soil. The pronounced variation is seen in the induced voltages for both types of disturbances.","PeriodicalId":120276,"journal":{"name":"2022 Workshop on Communication Networks and Power Systems (WCNPS)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124862271","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 : 2022-11-17DOI: 10.1109/WCNPS56355.2022.9969722
Carlos Augusto Melo de Pinho, F. Lima
In this article, Intelligent Reflecting Surface (IRS) technology is used to assist a Wireless Powered Communication Network (WPCN) system composed of a Hybrid Access Point (HAP) and multiple devices during downlink and uplink phases. In the downlink, devices charge their batteries through Wireless Power Transfer (WPT) from the power signals coming directly from the HAP and from the signals reflected by the IRS. In the uplink, the devices transmit their information signals to the HAP by employing Non-Orthogonal Multiple Access (NOMA). In the HAP, information is decoded through Successive Interference Cancellation (SIC). Based on this system model, an optimization problem is formulated so as to maximize the total uplink data rate subject to individual Quality of Service (QoS) guarantees for devices where IRS's phase shifts, uplink/downlink time duration and device ordering in SIC are optimized. Motivated by the high complexity of the optimization problem, we employ alternate optimization where Genetic Algorithm (GA) is used to define IRS's phase shifts in uplink/downlink and a heuristic solution is employed to optimize the remaining variables. Simulation results show that the proposed solution is able to satisfy different levels of QoS demands with higher spectral efficiency compared to baseline solutions.
{"title":"Rate maximization with QoS guarantees in IRS-assisted WPCN-NOMA systems","authors":"Carlos Augusto Melo de Pinho, F. Lima","doi":"10.1109/WCNPS56355.2022.9969722","DOIUrl":"https://doi.org/10.1109/WCNPS56355.2022.9969722","url":null,"abstract":"In this article, Intelligent Reflecting Surface (IRS) technology is used to assist a Wireless Powered Communication Network (WPCN) system composed of a Hybrid Access Point (HAP) and multiple devices during downlink and uplink phases. In the downlink, devices charge their batteries through Wireless Power Transfer (WPT) from the power signals coming directly from the HAP and from the signals reflected by the IRS. In the uplink, the devices transmit their information signals to the HAP by employing Non-Orthogonal Multiple Access (NOMA). In the HAP, information is decoded through Successive Interference Cancellation (SIC). Based on this system model, an optimization problem is formulated so as to maximize the total uplink data rate subject to individual Quality of Service (QoS) guarantees for devices where IRS's phase shifts, uplink/downlink time duration and device ordering in SIC are optimized. Motivated by the high complexity of the optimization problem, we employ alternate optimization where Genetic Algorithm (GA) is used to define IRS's phase shifts in uplink/downlink and a heuristic solution is employed to optimize the remaining variables. Simulation results show that the proposed solution is able to satisfy different levels of QoS demands with higher spectral efficiency compared to baseline solutions.","PeriodicalId":120276,"journal":{"name":"2022 Workshop on Communication Networks and Power Systems (WCNPS)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129611107","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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