Pub Date : 2022-05-29DOI: 10.1109/ICHQP53011.2022.9808668
Mateus M. de Oliveira, M. Lima, L. Silva, C. Duque, P. F. Ribeiro
The analysis of the harmonic distortion contribution on the PCC, traditionally, quantifies only the contribution from the load side (or distributed generation) and from the main source side. However, it is necessary to quantify the individual contributions of the different harmonic sources present in the system at a chosen point. For this it is necessary to estimate the transfer impedances from each source to the chosen point. This work presents a methodology to estimate the transfer impedance matrix Zk of the system using the Independent Component Analysis (ICA) technique. The methodology uses the currents and voltages acquired at the PCCs of each source and at the chosen point. The proposed method for estimating Zk is a passive method that explores the natural variations of harmonic sources. With Zk and the harmonic current injections of each source (estimated by the ICA) it is possible to identify the individual harmonic contributions at the chosen point. Due to the time-varying nature of harmonic distortion the method is intended for periodical estimations. The performance and effectiveness of the proposed method are demonstrated by simulating a Benchmark test system to evaluate the harmonic contribution.
{"title":"Independent Component Analysis for Distortion Estimation at Different Points of a Network with Multiple Harmonic Sources","authors":"Mateus M. de Oliveira, M. Lima, L. Silva, C. Duque, P. F. Ribeiro","doi":"10.1109/ICHQP53011.2022.9808668","DOIUrl":"https://doi.org/10.1109/ICHQP53011.2022.9808668","url":null,"abstract":"The analysis of the harmonic distortion contribution on the PCC, traditionally, quantifies only the contribution from the load side (or distributed generation) and from the main source side. However, it is necessary to quantify the individual contributions of the different harmonic sources present in the system at a chosen point. For this it is necessary to estimate the transfer impedances from each source to the chosen point. This work presents a methodology to estimate the transfer impedance matrix Zk of the system using the Independent Component Analysis (ICA) technique. The methodology uses the currents and voltages acquired at the PCCs of each source and at the chosen point. The proposed method for estimating Zk is a passive method that explores the natural variations of harmonic sources. With Zk and the harmonic current injections of each source (estimated by the ICA) it is possible to identify the individual harmonic contributions at the chosen point. Due to the time-varying nature of harmonic distortion the method is intended for periodical estimations. The performance and effectiveness of the proposed method are demonstrated by simulating a Benchmark test system to evaluate the harmonic contribution.","PeriodicalId":249133,"journal":{"name":"2022 20th International Conference on Harmonics & Quality of Power (ICHQP)","volume":"272 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115963661","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 : 2022-05-29DOI: 10.1109/ICHQP53011.2022.9808798
Manav Giri, S. Rönnberg, M. Bollen
The paper contains a set of observations on the fast charging of electric vehicles (EV’s) on Swedish low voltage networks in rural/commercial and urban areas. The emphasis of the study has been to analyze the impact of EV charging on the electric grid and particularly on the observed waveform distortion. The paper focuses on the observation of harmonics on the grid and the variation in the observed harmonics with time as the charging current increases from a small value associated with limiting the inrush current, to the value required by the EV’s for the fast charging of the battery pack. Observations from a bus charging station at Gothenburg are also discussed.
{"title":"Observed Harmonic Levels on the Low Voltage Grid during EV DC Fast Charging","authors":"Manav Giri, S. Rönnberg, M. Bollen","doi":"10.1109/ICHQP53011.2022.9808798","DOIUrl":"https://doi.org/10.1109/ICHQP53011.2022.9808798","url":null,"abstract":"The paper contains a set of observations on the fast charging of electric vehicles (EV’s) on Swedish low voltage networks in rural/commercial and urban areas. The emphasis of the study has been to analyze the impact of EV charging on the electric grid and particularly on the observed waveform distortion. The paper focuses on the observation of harmonics on the grid and the variation in the observed harmonics with time as the charging current increases from a small value associated with limiting the inrush current, to the value required by the EV’s for the fast charging of the battery pack. Observations from a bus charging station at Gothenburg are also discussed.","PeriodicalId":249133,"journal":{"name":"2022 20th International Conference on Harmonics & Quality of Power (ICHQP)","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115802374","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 : 2022-05-29DOI: 10.1109/ICHQP53011.2022.9808648
E. Gutiérrez-Ballesteros, S. Rönnberg, A. Gil-de-Castro
The topology of a device will determine the impact said device has on the grid and how immune that device is for disturbances in the grid. LED lamps are very commonly used devices, with different topologies available in the market, each topology showing different behavior when connected to a grid. For power quality studies, it is important to classify LED lamps, without breaking them to know the topology. Several classification methods are found in the literature with this purpose. In this paper, four methods from different papers for classifying LED lamps have been applied to a group of 21 LED lamps with active power consumption below 25 W. It has been observed that the applicability of the methods may lead to a gap of knowledge needed for classification, leaving space for personal criteria when classifying. that can be afforded using unsupervised Machine Learning.
{"title":"Applicability of LED lamps classification methods","authors":"E. Gutiérrez-Ballesteros, S. Rönnberg, A. Gil-de-Castro","doi":"10.1109/ICHQP53011.2022.9808648","DOIUrl":"https://doi.org/10.1109/ICHQP53011.2022.9808648","url":null,"abstract":"The topology of a device will determine the impact said device has on the grid and how immune that device is for disturbances in the grid. LED lamps are very commonly used devices, with different topologies available in the market, each topology showing different behavior when connected to a grid. For power quality studies, it is important to classify LED lamps, without breaking them to know the topology. Several classification methods are found in the literature with this purpose. In this paper, four methods from different papers for classifying LED lamps have been applied to a group of 21 LED lamps with active power consumption below 25 W. It has been observed that the applicability of the methods may lead to a gap of knowledge needed for classification, leaving space for personal criteria when classifying. that can be afforded using unsupervised Machine Learning.","PeriodicalId":249133,"journal":{"name":"2022 20th International Conference on Harmonics & Quality of Power (ICHQP)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132338657","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 : 2022-05-29DOI: 10.1109/ICHQP53011.2022.9808555
D. Giordano, G. Crotti, P. S. Letizia, D. Palladini
Power Quality (PQ) monitoring is one of the key tasks in modern power systems. In transmission and distribution grids, PQ phenomena are often measured by inductive Voltage Transformers (VTs) installed for metering and/or protection applications. VTs accuracy requirements should be ideally met under actual operating conditions, which can differ from the calibration ones, in particular for the presence of environmental or circuital influence factors. The impact of such influence factors on the VT performance in PQ measurements is an open issue, not fully addressed in the literature. In this respect, this paper presents a simplified numerical-experimental model of inductive MV VTs, which can be used for the analysis of VT wideband behaviour in PQ applications, also in presence of one or more influence factors. The results provided by the model are experimentally validated and future applications are discussed.
{"title":"Stray Parameter Evaluation of Voltage Transformers for PQ Measurement in MV Applications","authors":"D. Giordano, G. Crotti, P. S. Letizia, D. Palladini","doi":"10.1109/ICHQP53011.2022.9808555","DOIUrl":"https://doi.org/10.1109/ICHQP53011.2022.9808555","url":null,"abstract":"Power Quality (PQ) monitoring is one of the key tasks in modern power systems. In transmission and distribution grids, PQ phenomena are often measured by inductive Voltage Transformers (VTs) installed for metering and/or protection applications. VTs accuracy requirements should be ideally met under actual operating conditions, which can differ from the calibration ones, in particular for the presence of environmental or circuital influence factors. The impact of such influence factors on the VT performance in PQ measurements is an open issue, not fully addressed in the literature. In this respect, this paper presents a simplified numerical-experimental model of inductive MV VTs, which can be used for the analysis of VT wideband behaviour in PQ applications, also in presence of one or more influence factors. The results provided by the model are experimentally validated and future applications are discussed.","PeriodicalId":249133,"journal":{"name":"2022 20th International Conference on Harmonics & Quality of Power (ICHQP)","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126878573","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 : 2022-05-29DOI: 10.1109/ICHQP53011.2022.9808577
P. Castello, C. Muscas, P. Pegoraro, S. Sulis, J. Rens, Jacobus Van Zyl
Different solutions are available to monitor system technical performance in modern power systems. Innovative cloud computing solutions that host and analyse field data are realized as high bandwidth communication are nowadays affordable and simple. Accurate time synchronization of geographically separated instruments produces network coherent data that can be further exploited towards a deeper and comprehensive understanding of grid status. This paper presents the opportunity, making use of a power quality management solution, to reliably derive the geographical location of a voltage waveform event in supporting root-cause analysis of a network disturbance simultaneously observed at different points of delivery in an electric power system.
{"title":"Power Quality Data Platform for Analysis and Location of Voltage Dips: a Preliminary Study","authors":"P. Castello, C. Muscas, P. Pegoraro, S. Sulis, J. Rens, Jacobus Van Zyl","doi":"10.1109/ICHQP53011.2022.9808577","DOIUrl":"https://doi.org/10.1109/ICHQP53011.2022.9808577","url":null,"abstract":"Different solutions are available to monitor system technical performance in modern power systems. Innovative cloud computing solutions that host and analyse field data are realized as high bandwidth communication are nowadays affordable and simple. Accurate time synchronization of geographically separated instruments produces network coherent data that can be further exploited towards a deeper and comprehensive understanding of grid status. This paper presents the opportunity, making use of a power quality management solution, to reliably derive the geographical location of a voltage waveform event in supporting root-cause analysis of a network disturbance simultaneously observed at different points of delivery in an electric power system.","PeriodicalId":249133,"journal":{"name":"2022 20th International Conference on Harmonics & Quality of Power (ICHQP)","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114465768","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 : 2022-05-29DOI: 10.1109/ICHQP53011.2022.9808637
A. Špelko, I. Papič, S. Djokic, Z. Iqbal
This paper evaluates two commonly used methods that require information either on network harmonic impedance (IEC method), or on both network and customer installation harmonic impedances (voltage harmonic vector, VHV, method) for determining network and customer contributions to the total voltage harmonic distortion. The paper compares results of the IEC and VHV methods obtained with actual and reference impedances, which are also cross-correlated with the third method (voltage-only method, VoM), which does not rely on the use of either network or customer impedances. The results are obtained for a MV benchmark network model (BNM) proposed by IEEE-PES TF, which features network background distortion, harmonic resonance, different compensator types and customers with both linear and nonlinear loads. The results of VoM, IEC and VHV methods are discussed and illustrated for a range of harmonic interactions, with particular attention paid to the analysis of resonance conditions in the BNM.
{"title":"Use of Actual and Reference Impedances in Two Harmonic Emission Assessment Methods","authors":"A. Špelko, I. Papič, S. Djokic, Z. Iqbal","doi":"10.1109/ICHQP53011.2022.9808637","DOIUrl":"https://doi.org/10.1109/ICHQP53011.2022.9808637","url":null,"abstract":"This paper evaluates two commonly used methods that require information either on network harmonic impedance (IEC method), or on both network and customer installation harmonic impedances (voltage harmonic vector, VHV, method) for determining network and customer contributions to the total voltage harmonic distortion. The paper compares results of the IEC and VHV methods obtained with actual and reference impedances, which are also cross-correlated with the third method (voltage-only method, VoM), which does not rely on the use of either network or customer impedances. The results are obtained for a MV benchmark network model (BNM) proposed by IEEE-PES TF, which features network background distortion, harmonic resonance, different compensator types and customers with both linear and nonlinear loads. The results of VoM, IEC and VHV methods are discussed and illustrated for a range of harmonic interactions, with particular attention paid to the analysis of resonance conditions in the BNM.","PeriodicalId":249133,"journal":{"name":"2022 20th International Conference on Harmonics & Quality of Power (ICHQP)","volume":"79 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116095269","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 : 2022-05-29DOI: 10.1109/ICHQP53011.2022.9808594
L. Kukačka, J. Drapela, Jan Meyer, R. Stiegler
An alternative algorithm for estimating flicker severity from voltage measurements was developed and published in literature and is currently under consideration by IEC SC77A WG2 for replacing the current standard flickermeter algorithm as described in IEC 61000-4-15. This paper compares the response of the two algorithms to voltage components and modulations with frequency above the fundamental.
{"title":"Response of Flicker Assessment Algorithms to Interharmonic Distortion Patterns","authors":"L. Kukačka, J. Drapela, Jan Meyer, R. Stiegler","doi":"10.1109/ICHQP53011.2022.9808594","DOIUrl":"https://doi.org/10.1109/ICHQP53011.2022.9808594","url":null,"abstract":"An alternative algorithm for estimating flicker severity from voltage measurements was developed and published in literature and is currently under consideration by IEC SC77A WG2 for replacing the current standard flickermeter algorithm as described in IEC 61000-4-15. This paper compares the response of the two algorithms to voltage components and modulations with frequency above the fundamental.","PeriodicalId":249133,"journal":{"name":"2022 20th International Conference on Harmonics & Quality of Power (ICHQP)","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122109807","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 : 2022-05-29DOI: 10.1109/ICHQP53011.2022.9808740
Rodolfo A. R. Moura, D. Mestriner, R. Procopio, M. Schroeder, F. A. Assis, F. Delfino
For the study of lightning performance of distribution lines, the correct assessment of indirect flashes plays an important role. Thus, this paper considers the frequency-dependent soil electrical parameters in a previously developed approximate formula for the peak value of lightning-induced overvoltage on overhead lines. This approach consists of using a specific frequency (based on the lightning front time) to estimate the ground conductivity. Since the proposal is easy to implement and fast to run in any computational environment, it is a practical engineering tool. According to the results, it is possible to note the importance of applying models that take into account the variation of soil parameters with frequency, since overvoltage reductions for high resistivity soils above 35% were verified.
{"title":"Lightning-Induced Overvoltage Peaks Considering Soil Parameters Frequency-Dependence: New Approach with Dominant Frequency Associated with Lightning Current Front Time","authors":"Rodolfo A. R. Moura, D. Mestriner, R. Procopio, M. Schroeder, F. A. Assis, F. Delfino","doi":"10.1109/ICHQP53011.2022.9808740","DOIUrl":"https://doi.org/10.1109/ICHQP53011.2022.9808740","url":null,"abstract":"For the study of lightning performance of distribution lines, the correct assessment of indirect flashes plays an important role. Thus, this paper considers the frequency-dependent soil electrical parameters in a previously developed approximate formula for the peak value of lightning-induced overvoltage on overhead lines. This approach consists of using a specific frequency (based on the lightning front time) to estimate the ground conductivity. Since the proposal is easy to implement and fast to run in any computational environment, it is a practical engineering tool. According to the results, it is possible to note the importance of applying models that take into account the variation of soil parameters with frequency, since overvoltage reductions for high resistivity soils above 35% were verified.","PeriodicalId":249133,"journal":{"name":"2022 20th International Conference on Harmonics & Quality of Power (ICHQP)","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117267115","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 : 2022-05-29DOI: 10.1109/ICHQP53011.2022.9808479
V. Erhan, T. Slangen, V. Ćuk, J. Cobben, T. van Wijk
The supraharmonic distortion levels and their propagation in low voltage networks are determined by the supraharmonic- or frequency-dependent network impedance (FDNI). Knowledge of the FDNI is limited and mainly based on assumptions, measurements to determine the actual values are uncommon and not readily available. In this research, a current injection-based measurement system is developed to measure the impedance from 10 to 150 kHz at low voltage installations. The measurement system is validated using lab measurements and a measurement campaign at different residential- and office installations is carried out to quantify the network impedance. It is found that both the amplitude of the impedance and the resonant frequencies are highly influenced by devices connected locally. The results provide typical ranges of the FDNI in low-voltage installations and contribute to the assessment of supraharmonic impact and propagation.
{"title":"Measurement and Analysis of the Low Voltage Network Impedance in the Supraharmonic Range","authors":"V. Erhan, T. Slangen, V. Ćuk, J. Cobben, T. van Wijk","doi":"10.1109/ICHQP53011.2022.9808479","DOIUrl":"https://doi.org/10.1109/ICHQP53011.2022.9808479","url":null,"abstract":"The supraharmonic distortion levels and their propagation in low voltage networks are determined by the supraharmonic- or frequency-dependent network impedance (FDNI). Knowledge of the FDNI is limited and mainly based on assumptions, measurements to determine the actual values are uncommon and not readily available. In this research, a current injection-based measurement system is developed to measure the impedance from 10 to 150 kHz at low voltage installations. The measurement system is validated using lab measurements and a measurement campaign at different residential- and office installations is carried out to quantify the network impedance. It is found that both the amplitude of the impedance and the resonant frequencies are highly influenced by devices connected locally. The results provide typical ranges of the FDNI in low-voltage installations and contribute to the assessment of supraharmonic impact and propagation.","PeriodicalId":249133,"journal":{"name":"2022 20th International Conference on Harmonics & Quality of Power (ICHQP)","volume":"1749 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129469677","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 : 2022-05-29DOI: 10.1109/ICHQP53011.2022.9808564
D. Flumian, P. Ladoux, E. Sarraute
This paper presents a method to determine the voltage unbalance factor for a 25kV/50Hz railway substation taking into account the power drawn by the trains. In order to correctly size a balancing system to be associated with the substation, it is necessary to calculate with precision the voltage unbalance factor. Some authors proposed empirical formulas intended to determine the voltage unbalance factor using the apparent powers. However, because they don't consider separately active and reactive powers, these formulas are inaccurate and become unusable when a balancing system is connected.In the first part, this paper proposes a substation modelling which allows to calculate the upstream line voltages considering the power consumption of the substation. In the second part of the paper, the same approach is applied considering the connection of an unbalance compensator based on a Steinmetz circuit controlled by AC choppers.
{"title":"Calculation of the Voltage Unbalance Factor for 25kV-50Hz Railway Substations","authors":"D. Flumian, P. Ladoux, E. Sarraute","doi":"10.1109/ICHQP53011.2022.9808564","DOIUrl":"https://doi.org/10.1109/ICHQP53011.2022.9808564","url":null,"abstract":"This paper presents a method to determine the voltage unbalance factor for a 25kV/50Hz railway substation taking into account the power drawn by the trains. In order to correctly size a balancing system to be associated with the substation, it is necessary to calculate with precision the voltage unbalance factor. Some authors proposed empirical formulas intended to determine the voltage unbalance factor using the apparent powers. However, because they don't consider separately active and reactive powers, these formulas are inaccurate and become unusable when a balancing system is connected.In the first part, this paper proposes a substation modelling which allows to calculate the upstream line voltages considering the power consumption of the substation. In the second part of the paper, the same approach is applied considering the connection of an unbalance compensator based on a Steinmetz circuit controlled by AC choppers.","PeriodicalId":249133,"journal":{"name":"2022 20th International Conference on Harmonics & Quality of Power (ICHQP)","volume":"100 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129136634","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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