Pub Date : 2013-04-22DOI: 10.1109/ESTS.2013.6523757
G. Sulligoi, D. Bosich, R. Baldi, F. Tosato
High Voltage Shore Connection (HVSC) is a technical solution to supply ships at berth in an economic way while reducing air pollution in city ports. The increased power demand of modern cruise ships may reach several tens of MVA, requiring a primary port voltage supply at voltage >100 kV. When a phase-to-ground fault arises on the HV side, safety problems due to increasing ship hull touch voltage may arise. A possible solution is proposed in this paper, based on an HV/HV y-Δ-y transformer with secondary resistance grounded neutral in the distribution power supply utility substation, with the aim to reduce phase-to-ground fault current at port.
{"title":"Limiting hull touch voltages in large power shore connection systems during phase-to-ground faults: A solution proposal","authors":"G. Sulligoi, D. Bosich, R. Baldi, F. Tosato","doi":"10.1109/ESTS.2013.6523757","DOIUrl":"https://doi.org/10.1109/ESTS.2013.6523757","url":null,"abstract":"High Voltage Shore Connection (HVSC) is a technical solution to supply ships at berth in an economic way while reducing air pollution in city ports. The increased power demand of modern cruise ships may reach several tens of MVA, requiring a primary port voltage supply at voltage >100 kV. When a phase-to-ground fault arises on the HV side, safety problems due to increasing ship hull touch voltage may arise. A possible solution is proposed in this paper, based on an HV/HV y-Δ-y transformer with secondary resistance grounded neutral in the distribution power supply utility substation, with the aim to reduce phase-to-ground fault current at port.","PeriodicalId":119318,"journal":{"name":"2013 IEEE Electric Ship Technologies Symposium (ESTS)","volume":"254 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117323707","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 : 2013-04-22DOI: 10.1109/ESTS.2013.6523715
T. Chiocchio, R. Schrattenecker, S. Yang, J. Ordonez, M. Steurer
This paper presents a method to perform real-time system-level shipboard thermal simulations. The modeling approach is described in detail as the method is applied to the cooling facilities of the CAPS 5 MW MV laboratory. The derived simulation is studied using standard model validation tools such as factor screening and uncertainty propagation. Error bounds of system response variables are compared to results from experiments on the CAPS cooling facilities published previously. The goal is to provide a first step in the development of real-time system-level thermal simulations suitable for future HIL simulations employed in the engineering of future all-electric ships. It is envisioned that these simulations will be useful for the development and testing of future system-level controls.
{"title":"Developing a validated real-time system-level thermal simulation for future all-electric ships","authors":"T. Chiocchio, R. Schrattenecker, S. Yang, J. Ordonez, M. Steurer","doi":"10.1109/ESTS.2013.6523715","DOIUrl":"https://doi.org/10.1109/ESTS.2013.6523715","url":null,"abstract":"This paper presents a method to perform real-time system-level shipboard thermal simulations. The modeling approach is described in detail as the method is applied to the cooling facilities of the CAPS 5 MW MV laboratory. The derived simulation is studied using standard model validation tools such as factor screening and uncertainty propagation. Error bounds of system response variables are compared to results from experiments on the CAPS cooling facilities published previously. The goal is to provide a first step in the development of real-time system-level thermal simulations suitable for future HIL simulations employed in the engineering of future all-electric ships. It is envisioned that these simulations will be useful for the development and testing of future system-level controls.","PeriodicalId":119318,"journal":{"name":"2013 IEEE Electric Ship Technologies Symposium (ESTS)","volume":"115 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117108838","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 : 2013-04-22DOI: 10.1109/ESTS.2013.6523777
B. A. Correa, Yucheng Zhang, R. Dougal, T. Chiocchio, K. Schoder
This paper presents a method for driving an AC electric motor so that it emulates, at its drive shaft, the steady-state and transient loading and unloading dynamics of an aeroderivative twin-shaft gas turbine engine. This approach allows safe and robust testing of connected equipment, for example an electric generator, without having to install (or risk damage to) an actual gas turbine engine and all of its support systems. The lower inertia constant of an aeroderivative twin-shaft gas turbine relative to a comparably powerful AC motor introduces power, accuracy, and stability limitations in the emulation system. We have studied the performance of the emulation method at reduced scale using two identical 15 kW induction machines on a common shaft in which one machine acts as gas turbine emulation motor and the other one as a generator under test. The speed controller of the vector controlled emulation motor tracks the speed of a real time reference model of an aeroderivative twin-shaft gas turbine engine. Experimental results demonstrate the power and stability limitations that apply to the emulation system.
{"title":"Mechanical power-hardware-in-the-loop: Emulation of an aeroderivative twin-shaft turbine engine","authors":"B. A. Correa, Yucheng Zhang, R. Dougal, T. Chiocchio, K. Schoder","doi":"10.1109/ESTS.2013.6523777","DOIUrl":"https://doi.org/10.1109/ESTS.2013.6523777","url":null,"abstract":"This paper presents a method for driving an AC electric motor so that it emulates, at its drive shaft, the steady-state and transient loading and unloading dynamics of an aeroderivative twin-shaft gas turbine engine. This approach allows safe and robust testing of connected equipment, for example an electric generator, without having to install (or risk damage to) an actual gas turbine engine and all of its support systems. The lower inertia constant of an aeroderivative twin-shaft gas turbine relative to a comparably powerful AC motor introduces power, accuracy, and stability limitations in the emulation system. We have studied the performance of the emulation method at reduced scale using two identical 15 kW induction machines on a common shaft in which one machine acts as gas turbine emulation motor and the other one as a generator under test. The speed controller of the vector controlled emulation motor tracks the speed of a real time reference model of an aeroderivative twin-shaft gas turbine engine. Experimental results demonstrate the power and stability limitations that apply to the emulation system.","PeriodicalId":119318,"journal":{"name":"2013 IEEE Electric Ship Technologies Symposium (ESTS)","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115204498","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 : 2013-04-22DOI: 10.1109/ESTS.2013.6523737
S. Dawande, K. Lentijo
In order to provide excellent harmonic power quality equivalent to that of a synchronous generator, interleaved carriers and intercell transformers (ICTs) were included as part of an active-front end in a two-level, four-thread three-phase PWM drive to try to achieve 1% Total Harmonic Distortion (THD) and 0.3% Single Harmonic Distortion (SHD) for voltage up to 20 kHz on a high impedance grid. This highly compact drive rated up to 4 MW at 690 V with 2.5 kHz switching frequency is currently undergoing testing on a 480 V grid. The results of harmonic testing to date as well as a discussion of the role of the various inductance values associated with the design are included.
{"title":"Multi-megawatt drive with intercell transformers","authors":"S. Dawande, K. Lentijo","doi":"10.1109/ESTS.2013.6523737","DOIUrl":"https://doi.org/10.1109/ESTS.2013.6523737","url":null,"abstract":"In order to provide excellent harmonic power quality equivalent to that of a synchronous generator, interleaved carriers and intercell transformers (ICTs) were included as part of an active-front end in a two-level, four-thread three-phase PWM drive to try to achieve 1% Total Harmonic Distortion (THD) and 0.3% Single Harmonic Distortion (SHD) for voltage up to 20 kHz on a high impedance grid. This highly compact drive rated up to 4 MW at 690 V with 2.5 kHz switching frequency is currently undergoing testing on a 480 V grid. The results of harmonic testing to date as well as a discussion of the role of the various inductance values associated with the design are included.","PeriodicalId":119318,"journal":{"name":"2013 IEEE Electric Ship Technologies Symposium (ESTS)","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123771992","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 : 2013-04-22DOI: 10.1109/ESTS.2013.6523725
F. Uriarte, C. Dufour
Two methods to partition and parallelize the simulation of large-scale shipboard power systems on multicore computes are demonstrated. The first method is node tearing, which is used for offline simulation. The second is the state-space nodal method, which is used for real-time simulation. Both methods are benchmarked against MATLAB/Simulink 2012b for speed and accuracy The simulation model is a notional shipboard power system having characteristics of AC-radial, 450 V, 60 Hz, three-phase, delta-ungrounded power system. The parallel simulation results show speedups in excess of one order of magnitude and general agreement in accuracy.
{"title":"Multicore methods to accelerate ship power system simulations","authors":"F. Uriarte, C. Dufour","doi":"10.1109/ESTS.2013.6523725","DOIUrl":"https://doi.org/10.1109/ESTS.2013.6523725","url":null,"abstract":"Two methods to partition and parallelize the simulation of large-scale shipboard power systems on multicore computes are demonstrated. The first method is node tearing, which is used for offline simulation. The second is the state-space nodal method, which is used for real-time simulation. Both methods are benchmarked against MATLAB/Simulink 2012b for speed and accuracy The simulation model is a notional shipboard power system having characteristics of AC-radial, 450 V, 60 Hz, three-phase, delta-ungrounded power system. The parallel simulation results show speedups in excess of one order of magnitude and general agreement in accuracy.","PeriodicalId":119318,"journal":{"name":"2013 IEEE Electric Ship Technologies Symposium (ESTS)","volume":"123 23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129627409","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 : 2013-04-22DOI: 10.1109/ESTS.2013.6523785
J. Langston, M. Sloderbeck, M. Steurer, D. Dalessandro, T. Fikse
The hardware-in-the-loop (HIL) simulation approach (both controller HIL and power HIL) potentially offers a solution to several of the challenges presented in transitioning new technology to the fleet. However, the capabilities and limitations of the approach must be carefully considered in crafting the role of these tests into an overall testing program. This paper discusses some of these considerations, along with groundwork being conducted to begin to integrate HIL testing into the overall process, discussing the role that this approach may play.
{"title":"Role of hardware-in-the-loop simulation testing in transitioning new technology to the ship","authors":"J. Langston, M. Sloderbeck, M. Steurer, D. Dalessandro, T. Fikse","doi":"10.1109/ESTS.2013.6523785","DOIUrl":"https://doi.org/10.1109/ESTS.2013.6523785","url":null,"abstract":"The hardware-in-the-loop (HIL) simulation approach (both controller HIL and power HIL) potentially offers a solution to several of the challenges presented in transitioning new technology to the fleet. However, the capabilities and limitations of the approach must be carefully considered in crafting the role of these tests into an overall testing program. This paper discusses some of these considerations, along with groundwork being conducted to begin to integrate HIL testing into the overall process, discussing the role that this approach may play.","PeriodicalId":119318,"journal":{"name":"2013 IEEE Electric Ship Technologies Symposium (ESTS)","volume":"131 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123588121","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 : 2013-04-22DOI: 10.1109/ESTS.2013.6523722
D. Jurkiewicz, J. Chalfant, C. Chryssostomidis
Electrical power demands for naval surface combatants are projected to rise with the development of increasingly complex and power intensive combat systems. This trend coincides with the need to achieve maximum fuel efficiency at both high and low hull speeds. A proposed solution to meet current and future energy needs of conventionally powered naval surface combatants is through the use of an Integrated Power System (IPS), which is seen as the next evolution in naval ship design. In an effort to enhance the relationship between new-concept designs and historically-based ship design processes, this paper focuses on a novel approach of incorporating IPS at the earliest stage of the design process as part of assessing system-level tradeoffs early within the ship design process. This paper describes a methodology for the systematic design and arrangement of an IPS machinery plant to meet a desired power generation level. In conjunction with the methodology development, a hierarchical process and design tool were produced to assist in rapid development and evaluation of various IPS arrangements. The result of this process, through several case studies, provides insight into equipment selection philosophy, the initial sizing of the ship's machinery box, and the initial definition of electrical zones.
{"title":"Modular IPS machinery arrangement in early-stage naval ship design","authors":"D. Jurkiewicz, J. Chalfant, C. Chryssostomidis","doi":"10.1109/ESTS.2013.6523722","DOIUrl":"https://doi.org/10.1109/ESTS.2013.6523722","url":null,"abstract":"Electrical power demands for naval surface combatants are projected to rise with the development of increasingly complex and power intensive combat systems. This trend coincides with the need to achieve maximum fuel efficiency at both high and low hull speeds. A proposed solution to meet current and future energy needs of conventionally powered naval surface combatants is through the use of an Integrated Power System (IPS), which is seen as the next evolution in naval ship design. In an effort to enhance the relationship between new-concept designs and historically-based ship design processes, this paper focuses on a novel approach of incorporating IPS at the earliest stage of the design process as part of assessing system-level tradeoffs early within the ship design process. This paper describes a methodology for the systematic design and arrangement of an IPS machinery plant to meet a desired power generation level. In conjunction with the methodology development, a hierarchical process and design tool were produced to assist in rapid development and evaluation of various IPS arrangements. The result of this process, through several case studies, provides insight into equipment selection philosophy, the initial sizing of the ship's machinery box, and the initial definition of electrical zones.","PeriodicalId":119318,"journal":{"name":"2013 IEEE Electric Ship Technologies Symposium (ESTS)","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123776977","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 : 2013-04-22DOI: 10.1109/ESTS.2013.6523742
J. Leonard, C. Edrington
Integration of nonlinear dynamic loads has become a significant aspect of designing new ships with integrated power systems. System level simulation is one tool for improving performance in prototyping laboratories and ship yards but requires accurate models of these loads for high performance ship design. This paper utilizes the Volterra Series for nonlinear modeling and discusses methods for creating models, through Volterra kernel measurement, from time domain simulations or hardware prototypes. Design of a converter to realize the required input voltage exciter for model development of hardware prototypes is described. Simulation results of a traditional DC-DC boost converter load are presented along with a brief discussion on scaling methods for increased power levels.
{"title":"Modeling and simulation of shipboard nonlinear dynamic loads using Volterra kernels","authors":"J. Leonard, C. Edrington","doi":"10.1109/ESTS.2013.6523742","DOIUrl":"https://doi.org/10.1109/ESTS.2013.6523742","url":null,"abstract":"Integration of nonlinear dynamic loads has become a significant aspect of designing new ships with integrated power systems. System level simulation is one tool for improving performance in prototyping laboratories and ship yards but requires accurate models of these loads for high performance ship design. This paper utilizes the Volterra Series for nonlinear modeling and discusses methods for creating models, through Volterra kernel measurement, from time domain simulations or hardware prototypes. Design of a converter to realize the required input voltage exciter for model development of hardware prototypes is described. Simulation results of a traditional DC-DC boost converter load are presented along with a brief discussion on scaling methods for increased power levels.","PeriodicalId":119318,"journal":{"name":"2013 IEEE Electric Ship Technologies Symposium (ESTS)","volume":"199 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115513367","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 : 2013-04-22DOI: 10.1109/ESTS.2013.6523776
A. Tessarolo, C. Bruzzese, T. Mazzuca, G. Scala
In today's large ships a wide use is made of hydrostatic transmission systems combined with traditional hydraulic machinery, such as piston-, rotary-vane- and screw-motors and pumps, to operate high-torque low-speed onboard actuators like rudders, stabilizing fins and bow thrusters. Such mechanical drives are very cumbersome and suffer from serious maintenance and reliability issues. In this paper, a novel all-electric direct-drive oil-free drive solution is proposed based on an inverter-fed permanent magnet linear synchronous motor (PMLSM). The PMLSM is coupled to shipboard rotary equipment through an innovative kinematic chain, consisting of a tiller and a prismatic-rotoidal joint, that performs force to torque conversion. The advantages of the PMLSM solution are presented in the paper in terms of compactness, robustness, reliability, efficiency and maintenance. Furthermore, the design optimization of a technology demonstrator which is presently under construction is addressed.
{"title":"A novel fault-tolerant high-thrust inverter-controlled permanent magnet linear actuator as a direct-drive for shipboard loads","authors":"A. Tessarolo, C. Bruzzese, T. Mazzuca, G. Scala","doi":"10.1109/ESTS.2013.6523776","DOIUrl":"https://doi.org/10.1109/ESTS.2013.6523776","url":null,"abstract":"In today's large ships a wide use is made of hydrostatic transmission systems combined with traditional hydraulic machinery, such as piston-, rotary-vane- and screw-motors and pumps, to operate high-torque low-speed onboard actuators like rudders, stabilizing fins and bow thrusters. Such mechanical drives are very cumbersome and suffer from serious maintenance and reliability issues. In this paper, a novel all-electric direct-drive oil-free drive solution is proposed based on an inverter-fed permanent magnet linear synchronous motor (PMLSM). The PMLSM is coupled to shipboard rotary equipment through an innovative kinematic chain, consisting of a tiller and a prismatic-rotoidal joint, that performs force to torque conversion. The advantages of the PMLSM solution are presented in the paper in terms of compactness, robustness, reliability, efficiency and maintenance. Furthermore, the design optimization of a technology demonstrator which is presently under construction is addressed.","PeriodicalId":119318,"journal":{"name":"2013 IEEE Electric Ship Technologies Symposium (ESTS)","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121129144","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 : 2013-04-22DOI: 10.1109/ESTS.2013.6523779
V. Staudt, R. Bartelt, C. Heising
DC grids offer highly efficient distribution of electric energy, eliminating components and optimizing the use of cables. Efficient generation, however, is still based on AC generators. Power-electronic devices link generators and grid and customize energy flow to the loads. Efficient distribution with low losses demands high voltage, e.g. in the range of 10 kV for ship-size grids. Such voltages challenge power electronics as well as protective devices: Harmonics, converter design and switch design are issues to be discussed. Fault scenarios, accepted recovery time, size and weight of components and redundancy as well as available technologies influence the selection of solutions. This paper analyses fault scenarios in DC grids with special regard to on-ship requirements. Existing power-electronic solutions are compared with options resulting from modular multilevel converters (MMC), analysing advantages and disadvantages of this relatively new technology for on-board use.
{"title":"Short-circuit protection issues in DC ship grids","authors":"V. Staudt, R. Bartelt, C. Heising","doi":"10.1109/ESTS.2013.6523779","DOIUrl":"https://doi.org/10.1109/ESTS.2013.6523779","url":null,"abstract":"DC grids offer highly efficient distribution of electric energy, eliminating components and optimizing the use of cables. Efficient generation, however, is still based on AC generators. Power-electronic devices link generators and grid and customize energy flow to the loads. Efficient distribution with low losses demands high voltage, e.g. in the range of 10 kV for ship-size grids. Such voltages challenge power electronics as well as protective devices: Harmonics, converter design and switch design are issues to be discussed. Fault scenarios, accepted recovery time, size and weight of components and redundancy as well as available technologies influence the selection of solutions. This paper analyses fault scenarios in DC grids with special regard to on-ship requirements. Existing power-electronic solutions are compared with options resulting from modular multilevel converters (MMC), analysing advantages and disadvantages of this relatively new technology for on-board use.","PeriodicalId":119318,"journal":{"name":"2013 IEEE Electric Ship Technologies Symposium (ESTS)","volume":"72 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127131988","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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