Pub Date : 2003-12-15DOI: 10.1109/PECON.2003.1437430
N. D. Muhamad, A.J. Shafie
A new approach to using Pspice in designing feedback for DC-DC converter systems is introduced in this paper. In this new approach, the feedback design procedures are programmed and made as a subcircuit in Pspice. For this purpose, an option available in Pspice called analog behavioral modeling (ABM) is used. By using the subcircuit, the component values of the error amplifier can be easily obtained by means of Pspice DC analysis. The methodology of development is presented in detail. Application examples are included to demonstrate the effectiveness of the proposed approach in designing feedbacks for DC-DC converters.
{"title":"An approach to Pspice-aided control loop design of DC-DC converter systems","authors":"N. D. Muhamad, A.J. Shafie","doi":"10.1109/PECON.2003.1437430","DOIUrl":"https://doi.org/10.1109/PECON.2003.1437430","url":null,"abstract":"A new approach to using Pspice in designing feedback for DC-DC converter systems is introduced in this paper. In this new approach, the feedback design procedures are programmed and made as a subcircuit in Pspice. For this purpose, an option available in Pspice called analog behavioral modeling (ABM) is used. By using the subcircuit, the component values of the error amplifier can be easily obtained by means of Pspice DC analysis. The methodology of development is presented in detail. Application examples are included to demonstrate the effectiveness of the proposed approach in designing feedbacks for DC-DC converters.","PeriodicalId":136640,"journal":{"name":"Proceedings. National Power Engineering Conference, 2003. PECon 2003.","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126894962","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 : 2003-12-15DOI: 10.1109/PECON.2003.1437441
P. Khan, J. K. Chatterjee
Application of inductively loaded current controlled solid-state lead-lag (ICSL) VAr compensator for voltage control of SEIG has been reported in this paper. From both theoretical and experimental results it is observed that the integrated system of ICSL VAr Compensator and SEIG is able to supply power to wide range of loads at constant output voltage with acceptable supply frequency variation. The system is proposed for application in renewable energy conversion where the SEIG can be driven by unregulated microhydro turbine in constant water head or by wind turbine in a limited range of wind speed variation. The results are critically analysed and the effectiveness of the system for low cost remote area power supply has been discussed in the paper.
{"title":"Integration of solid-state lead-lag VAr compensator and self-excited induction generator for low cost power generation","authors":"P. Khan, J. K. Chatterjee","doi":"10.1109/PECON.2003.1437441","DOIUrl":"https://doi.org/10.1109/PECON.2003.1437441","url":null,"abstract":"Application of inductively loaded current controlled solid-state lead-lag (ICSL) VAr compensator for voltage control of SEIG has been reported in this paper. From both theoretical and experimental results it is observed that the integrated system of ICSL VAr Compensator and SEIG is able to supply power to wide range of loads at constant output voltage with acceptable supply frequency variation. The system is proposed for application in renewable energy conversion where the SEIG can be driven by unregulated microhydro turbine in constant water head or by wind turbine in a limited range of wind speed variation. The results are critically analysed and the effectiveness of the system for low cost remote area power supply has been discussed in the paper.","PeriodicalId":136640,"journal":{"name":"Proceedings. National Power Engineering Conference, 2003. PECon 2003.","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129027482","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 : 2003-12-15DOI: 10.1109/PECON.2003.1437460
M. Shawal, S. Taib
Renewable energy sources are increasingly being considered as viable alternatives to conventional supply system, in the provision of electricity to isolated communities especially in the rural and semirural areas. Traditionally, rural loads are supplied from stand-alone diesel power station or via grid extension. Such sources are sometimes not cost effective due to the high fuel and maintenance cost of diesel stations, as well as, long distances from the grid to the loads. Due to this reason, renewable energy (RE) is selected for electricity supplier, photovoltaic (PV) is one of the suitable RE to replace the conventional suppliers. This paper describes the procedures used to evaluate the power supply technologies model and deployment strategy. Many factors are considered including cost effective, environment impact, payback period, resources availability and efficiency. The final product of this research will be a tool that will give a complete model of photovoltaic system for the selected area.
{"title":"Development of expert system as an evaluation tool for photovoltaic power supply","authors":"M. Shawal, S. Taib","doi":"10.1109/PECON.2003.1437460","DOIUrl":"https://doi.org/10.1109/PECON.2003.1437460","url":null,"abstract":"Renewable energy sources are increasingly being considered as viable alternatives to conventional supply system, in the provision of electricity to isolated communities especially in the rural and semirural areas. Traditionally, rural loads are supplied from stand-alone diesel power station or via grid extension. Such sources are sometimes not cost effective due to the high fuel and maintenance cost of diesel stations, as well as, long distances from the grid to the loads. Due to this reason, renewable energy (RE) is selected for electricity supplier, photovoltaic (PV) is one of the suitable RE to replace the conventional suppliers. This paper describes the procedures used to evaluate the power supply technologies model and deployment strategy. Many factors are considered including cost effective, environment impact, payback period, resources availability and efficiency. The final product of this research will be a tool that will give a complete model of photovoltaic system for the selected area.","PeriodicalId":136640,"journal":{"name":"Proceedings. National Power Engineering Conference, 2003. PECon 2003.","volume":"201 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124497678","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 : 2003-12-15DOI: 10.1109/PECON.2003.1437431
K. Rao
This paper presents the design optimization of a 3-phase, 6-pulse converter fed DC series motor for minimum material cost using non linear programming (NLP) technique. A mathematical model with 16 design variables, some of them representing the physical dimensions of the motor, is formulated. An octagonal frame for the yoke and poles, nonlinearity of the magnetic circuit, compensating winding in the pole faces and inter-pole winding are considered for the design. Some of the important constraints such as maximum reactance voltage of the commutating coil, maximum voltage between commutator segments, minimum clearance between the main field and inter-pole windings, ratio of torque to moment of inertia of armature, pulse duty factor with reference to armature current, efficiency of the motor etc., are imposed. The design analysis program includes armature circuit inductance calculations, harmonic currents due to rectified voltage, additional losses due to flux pulsations in the armature and magnetic circuit, skin effect in armature and inter-pole winding conductors. The design problem is converted into a sequence of unconstrained minimization problems by Zangwill's exterior penalty function method and Powell's minimization technique is applied to minimize the active material cost of a 150 h.p., 550 volts, 4-pole, 1500 r.p.m. DC series motor fed from a 6-pulse, 3-phase bridge converter. The effect of source impedance and of the triggering angle of the converter on the optimal solution is discussed. At the optimal solution, the torque and speed pulsations of the motor are investigated.
{"title":"Design optimization of 3-phase converter fed DC series motor","authors":"K. Rao","doi":"10.1109/PECON.2003.1437431","DOIUrl":"https://doi.org/10.1109/PECON.2003.1437431","url":null,"abstract":"This paper presents the design optimization of a 3-phase, 6-pulse converter fed DC series motor for minimum material cost using non linear programming (NLP) technique. A mathematical model with 16 design variables, some of them representing the physical dimensions of the motor, is formulated. An octagonal frame for the yoke and poles, nonlinearity of the magnetic circuit, compensating winding in the pole faces and inter-pole winding are considered for the design. Some of the important constraints such as maximum reactance voltage of the commutating coil, maximum voltage between commutator segments, minimum clearance between the main field and inter-pole windings, ratio of torque to moment of inertia of armature, pulse duty factor with reference to armature current, efficiency of the motor etc., are imposed. The design analysis program includes armature circuit inductance calculations, harmonic currents due to rectified voltage, additional losses due to flux pulsations in the armature and magnetic circuit, skin effect in armature and inter-pole winding conductors. The design problem is converted into a sequence of unconstrained minimization problems by Zangwill's exterior penalty function method and Powell's minimization technique is applied to minimize the active material cost of a 150 h.p., 550 volts, 4-pole, 1500 r.p.m. DC series motor fed from a 6-pulse, 3-phase bridge converter. The effect of source impedance and of the triggering angle of the converter on the optimal solution is discussed. At the optimal solution, the torque and speed pulsations of the motor are investigated.","PeriodicalId":136640,"journal":{"name":"Proceedings. National Power Engineering Conference, 2003. PECon 2003.","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131382901","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 : 2003-12-15DOI: 10.1109/PECON.2003.1437468
N.A. Bakar, A. Mohamed, M. Ismail
Voltage sags are momentary dips in voltage magnitude that can cause sensitive equipments to trip. Such occurrences have a major economic impact and therefore, the study of voltage sag has become a major effort worldwide. This paper presents a voltage sag analysis implemented on an actual distribution system. The objective of the study presented in this paper is to develop a suitable method for voltage sag analysis in which the method is demonstrated on a practical distribution system. The voltage sag analysis is performed using the commercial software PSS/ADEPT for performing load flow and short circuit simulations. The distribution network is modeled using the actual network data and the transmission system is considered as a source. Faults are introduced at various points in the system, at the buses and along the lines. Simulation results are presented in the form of voltage sag vulnerability areas.
{"title":"A case study of voltage sag analysis in a utility distribution system","authors":"N.A. Bakar, A. Mohamed, M. Ismail","doi":"10.1109/PECON.2003.1437468","DOIUrl":"https://doi.org/10.1109/PECON.2003.1437468","url":null,"abstract":"Voltage sags are momentary dips in voltage magnitude that can cause sensitive equipments to trip. Such occurrences have a major economic impact and therefore, the study of voltage sag has become a major effort worldwide. This paper presents a voltage sag analysis implemented on an actual distribution system. The objective of the study presented in this paper is to develop a suitable method for voltage sag analysis in which the method is demonstrated on a practical distribution system. The voltage sag analysis is performed using the commercial software PSS/ADEPT for performing load flow and short circuit simulations. The distribution network is modeled using the actual network data and the transmission system is considered as a source. Faults are introduced at various points in the system, at the buses and along the lines. Simulation results are presented in the form of voltage sag vulnerability areas.","PeriodicalId":136640,"journal":{"name":"Proceedings. National Power Engineering Conference, 2003. PECon 2003.","volume":"73 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128204228","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 : 2003-12-15DOI: 10.1109/PECON.2003.1437454
C.S. Hoong, S. Taib
This paper present the development of a low cost synchronous generator for wave energy. This paper presents the practical design consideration for the development of a high efficiency generator. It this found that in this design the power electronic drives for the system being reduced to a minimum cost because it only control the field excitation and the speed regulation of the generator. In practical the efficiency of the synchronous generator reached about 70.1% for 1.5 kW load with a voltage regulation of 27.5%.
{"title":"Development of three phase synchronous generator for ocean wave application","authors":"C.S. Hoong, S. Taib","doi":"10.1109/PECON.2003.1437454","DOIUrl":"https://doi.org/10.1109/PECON.2003.1437454","url":null,"abstract":"This paper present the development of a low cost synchronous generator for wave energy. This paper presents the practical design consideration for the development of a high efficiency generator. It this found that in this design the power electronic drives for the system being reduced to a minimum cost because it only control the field excitation and the speed regulation of the generator. In practical the efficiency of the synchronous generator reached about 70.1% for 1.5 kW load with a voltage regulation of 27.5%.","PeriodicalId":136640,"journal":{"name":"Proceedings. National Power Engineering Conference, 2003. PECon 2003.","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132743262","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 : 2003-12-15DOI: 10.1109/PECON.2003.1437457
W. Hew, J. Jamaludin, M. Tadjuddin, K. M. Nor
Research towards improving the performance of electric generators has become a great interest nowadays. Today, many applications require the generation of electric power without connection to the utility power system. For this purpose, the generator must be efficient, reliable and lightweight. A free-piston generator can fulfill these requirements. With this generation unit, the mechanical energy is transformed into electric power without the use of a crankshaft. This gains significant improvement in efficiency as well as volume and mass reduction. This paper presents a fabrication of a linear electric generator that is capable of generating 5 kW of power. The concept of a free-piston generator and a linear electric generator is reviewed. The design and fabrication processes are also covered. Performance evaluation is discussed as well.
{"title":"Fabrication and testing of linear electric generator for use with a free-piston engine","authors":"W. Hew, J. Jamaludin, M. Tadjuddin, K. M. Nor","doi":"10.1109/PECON.2003.1437457","DOIUrl":"https://doi.org/10.1109/PECON.2003.1437457","url":null,"abstract":"Research towards improving the performance of electric generators has become a great interest nowadays. Today, many applications require the generation of electric power without connection to the utility power system. For this purpose, the generator must be efficient, reliable and lightweight. A free-piston generator can fulfill these requirements. With this generation unit, the mechanical energy is transformed into electric power without the use of a crankshaft. This gains significant improvement in efficiency as well as volume and mass reduction. This paper presents a fabrication of a linear electric generator that is capable of generating 5 kW of power. The concept of a free-piston generator and a linear electric generator is reviewed. The design and fabrication processes are also covered. Performance evaluation is discussed as well.","PeriodicalId":136640,"journal":{"name":"Proceedings. National Power Engineering Conference, 2003. PECon 2003.","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114404340","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 : 2003-12-15DOI: 10.1109/PECON.2003.1437416
P. Dash, M. V. Chilukuri
This paper presents a soft computing tool namely the fuzzy neural network (FNN) based distance relaying of a transmission line operating with a thyristor controlled series capacitor (TCSC) protected by MOVs. The FNN structure is seen as a neural network for training and the fuzzy viewpoint is utilized to gain insight into the system and to simplify the model. The number of rules is determined by the data itself and therefore, a smaller number of rules is produced. The network is trained with back propagation algorithm with a pruning strategy to eliminate the redundant rules and fuzzification neurons resulting in a compact network structure. The classification and location tasks of the relay are accomplished using different FNNs. Once the fault type is identified by the classifier the selected FNN-locator estimates the location of the fault accurately. The networks make use of fundamental currents and voltages at the relay end, sequence components of current, system frequency and the firing angle of the TCSC to derive the trip decision. The superior capability of the strategy is adjudged through test results for different situations of power system including high resistance in the fault path.
{"title":"Soft computing tools for protection of compensated network","authors":"P. Dash, M. V. Chilukuri","doi":"10.1109/PECON.2003.1437416","DOIUrl":"https://doi.org/10.1109/PECON.2003.1437416","url":null,"abstract":"This paper presents a soft computing tool namely the fuzzy neural network (FNN) based distance relaying of a transmission line operating with a thyristor controlled series capacitor (TCSC) protected by MOVs. The FNN structure is seen as a neural network for training and the fuzzy viewpoint is utilized to gain insight into the system and to simplify the model. The number of rules is determined by the data itself and therefore, a smaller number of rules is produced. The network is trained with back propagation algorithm with a pruning strategy to eliminate the redundant rules and fuzzification neurons resulting in a compact network structure. The classification and location tasks of the relay are accomplished using different FNNs. Once the fault type is identified by the classifier the selected FNN-locator estimates the location of the fault accurately. The networks make use of fundamental currents and voltages at the relay end, sequence components of current, system frequency and the firing angle of the TCSC to derive the trip decision. The superior capability of the strategy is adjudged through test results for different situations of power system including high resistance in the fault path.","PeriodicalId":136640,"journal":{"name":"Proceedings. National Power Engineering Conference, 2003. PECon 2003.","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133845191","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 : 2003-12-15DOI: 10.1109/PECON.2003.1437422
S. Voon, J. Kong, R. Gobbi
Variable speed drives (VSD) is widely used in the industry because of the cost saving, reliability and easy control characteristics. VSD uses high switching frequency to reduce harmonics which causes disruption in motor performances. The phenomenon of EMI emissions from electronic devices has adverse effects on the accuracy of the data readings. This is very obvious in the process of converting and inverting the current signal where there are harmonics. The RFI component of EMI will couple either through conduction and/or radiation to the victims, i.e. temperature sensor. This may cause inconsistent changes of temperature reading instigating a premature shut down and costing millions of dollar in damages in automated industries. This paper mainly focuses on the total effect of the RFI which is due to the high switching frequency of the inverter on the reading of the temperature sensor by going through a series of experimentation and simulation steps.
{"title":"Effect of radio frequency interference (RFI) due to high switching frequency of inverter on temperature sensor","authors":"S. Voon, J. Kong, R. Gobbi","doi":"10.1109/PECON.2003.1437422","DOIUrl":"https://doi.org/10.1109/PECON.2003.1437422","url":null,"abstract":"Variable speed drives (VSD) is widely used in the industry because of the cost saving, reliability and easy control characteristics. VSD uses high switching frequency to reduce harmonics which causes disruption in motor performances. The phenomenon of EMI emissions from electronic devices has adverse effects on the accuracy of the data readings. This is very obvious in the process of converting and inverting the current signal where there are harmonics. The RFI component of EMI will couple either through conduction and/or radiation to the victims, i.e. temperature sensor. This may cause inconsistent changes of temperature reading instigating a premature shut down and costing millions of dollar in damages in automated industries. This paper mainly focuses on the total effect of the RFI which is due to the high switching frequency of the inverter on the reading of the temperature sensor by going through a series of experimentation and simulation steps.","PeriodicalId":136640,"journal":{"name":"Proceedings. National Power Engineering Conference, 2003. PECon 2003.","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125095463","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 : 2003-12-15DOI: 10.1109/PECON.2003.1437434
M. S. Bakar, N. Azli
Simulation of a multilevel inverter for high power applications employing a PWM unipolar symmetrical regular sampled technique based on a single carrier multilevel modulation strategy is presented in this paper. The equations related to this technique are used to design the gate signal generator blocks using Matlab Simulink. These blocks generate the gate signals for each of the multilevel inverter power devices and can later be compiled and downloaded to a dSPACE DSP controller board for real time digital implementation. The gate signal generator blocks are tested for various values of modulation index. The results of the simulation study are shown in the form of the PWM waveforms of the multilevel inverter modules as well as the gate signals for its power devices for comparison purposes.
{"title":"Simulation of a regular sampled pulsewidth modulation (PWM) technique for a multilevel inverter","authors":"M. S. Bakar, N. Azli","doi":"10.1109/PECON.2003.1437434","DOIUrl":"https://doi.org/10.1109/PECON.2003.1437434","url":null,"abstract":"Simulation of a multilevel inverter for high power applications employing a PWM unipolar symmetrical regular sampled technique based on a single carrier multilevel modulation strategy is presented in this paper. The equations related to this technique are used to design the gate signal generator blocks using Matlab Simulink. These blocks generate the gate signals for each of the multilevel inverter power devices and can later be compiled and downloaded to a dSPACE DSP controller board for real time digital implementation. The gate signal generator blocks are tested for various values of modulation index. The results of the simulation study are shown in the form of the PWM waveforms of the multilevel inverter modules as well as the gate signals for its power devices for comparison purposes.","PeriodicalId":136640,"journal":{"name":"Proceedings. National Power Engineering Conference, 2003. PECon 2003.","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127189660","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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