Pub Date : 2014-12-01DOI: 10.1109/IICPE.2014.7115829
Pothireddy Adarsh Reddy, B. Rajpurohit
The condition of transformer windings can be gauged by monitoring their equivalent circuit parameters. These parameters are not affected by external faults and change only in the presence of an internal aberration. Changes in the insulation temperature are reflected in winding temperature and can be monitored by observing the winding resistance values. Similarly changes in the short circuit reactance can give information on the condition and structure of windings. Rapid and reliable protection can be implemented by monitoring these parameters since inrush current and over-excitation does not affect these parameters. Presently, there is no accurate measurement method for the transformer winding parameters and generally require the transformer to be disconnected from the power system. A new simple algorithm for extracting transformer winding parameters which can be implemented online is presented in this paper. This method takes only the input currents and voltages as inputs and thereby eliminates the need for the disconnection of the transformer from the power system. In this method, winding parameters are obtained by solving the equivalent circuit equations in real time continuously which allows for interpretation and detection of faults in real-time. The proposed method has been tested and validated by simulations.
{"title":"On-line monitoring of winding parameters for single-phase transformers","authors":"Pothireddy Adarsh Reddy, B. Rajpurohit","doi":"10.1109/IICPE.2014.7115829","DOIUrl":"https://doi.org/10.1109/IICPE.2014.7115829","url":null,"abstract":"The condition of transformer windings can be gauged by monitoring their equivalent circuit parameters. These parameters are not affected by external faults and change only in the presence of an internal aberration. Changes in the insulation temperature are reflected in winding temperature and can be monitored by observing the winding resistance values. Similarly changes in the short circuit reactance can give information on the condition and structure of windings. Rapid and reliable protection can be implemented by monitoring these parameters since inrush current and over-excitation does not affect these parameters. Presently, there is no accurate measurement method for the transformer winding parameters and generally require the transformer to be disconnected from the power system. A new simple algorithm for extracting transformer winding parameters which can be implemented online is presented in this paper. This method takes only the input currents and voltages as inputs and thereby eliminates the need for the disconnection of the transformer from the power system. In this method, winding parameters are obtained by solving the equivalent circuit equations in real time continuously which allows for interpretation and detection of faults in real-time. The proposed method has been tested and validated by simulations.","PeriodicalId":206767,"journal":{"name":"2014 IEEE 6th India International Conference on Power Electronics (IICPE)","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133996093","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 : 2014-12-01DOI: 10.1109/IICPE.2014.7115787
Suresh Singh, Rakesh Kumar, V. Vijay
In the emerging photo-voltaic markets worldwide the use of appropriate estimation of the operating performance of the grid-connected PV systems is becoming more and more crucial. The widely used performance indices that are used to analyze the system performance with respect to energy output, solar resource and the effect of system losses in its various components are total yield, final yield/specific yield, performance ratio, PVUSA rating, and performance indicator based on ratio of ac power at PTC to dc power at STC. This paper presents performance analysis of a 43 kW amorphous-silicon thin-film grid-connected PV system. Recorded plant monitoring data during July 2011 to July 2014 is used for the analysis. Major operation and maintenance issues encountered in last three years are also reported.
{"title":"Performance monitoring of 43 kW thin-film grid-connected roof-top solar PV system","authors":"Suresh Singh, Rakesh Kumar, V. Vijay","doi":"10.1109/IICPE.2014.7115787","DOIUrl":"https://doi.org/10.1109/IICPE.2014.7115787","url":null,"abstract":"In the emerging photo-voltaic markets worldwide the use of appropriate estimation of the operating performance of the grid-connected PV systems is becoming more and more crucial. The widely used performance indices that are used to analyze the system performance with respect to energy output, solar resource and the effect of system losses in its various components are total yield, final yield/specific yield, performance ratio, PVUSA rating, and performance indicator based on ratio of ac power at PTC to dc power at STC. This paper presents performance analysis of a 43 kW amorphous-silicon thin-film grid-connected PV system. Recorded plant monitoring data during July 2011 to July 2014 is used for the analysis. Major operation and maintenance issues encountered in last three years are also reported.","PeriodicalId":206767,"journal":{"name":"2014 IEEE 6th India International Conference on Power Electronics (IICPE)","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125004095","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 : 2014-12-01DOI: 10.1109/IICPE.2014.7115842
H. Malik, S. Mishra
The diagnosis of incipient fault is very important for power transformer condition monitoring. The incipient faults are monitored by conventional and artificial intelligence (AI) based models. In this paper, the Proximal Support Vector Machine (PSVM) has been utilized to identify the incipient type of faults in an oil-immersed power transformer. Its performance is compared with traditional IEC/IEEE and AI methods (i.e. ANN and SVM). The juxtaposition of fault classification of ANN and SVM method notify that proposed approach is much swiftly. Simultaneous identification of oil immersed power transformer incipient faults has never been identified formerly by using Multi-PSVM. The desired test analysis of experimental data from working transformers in the Northern Power Grid of India has been executed to present the robustness of evaluated incipient faults for large variation in loading and operational conditions perturbations.
{"title":"Fault identification of power transformers using Proximal Support Vector Machine (PSVM)","authors":"H. Malik, S. Mishra","doi":"10.1109/IICPE.2014.7115842","DOIUrl":"https://doi.org/10.1109/IICPE.2014.7115842","url":null,"abstract":"The diagnosis of incipient fault is very important for power transformer condition monitoring. The incipient faults are monitored by conventional and artificial intelligence (AI) based models. In this paper, the Proximal Support Vector Machine (PSVM) has been utilized to identify the incipient type of faults in an oil-immersed power transformer. Its performance is compared with traditional IEC/IEEE and AI methods (i.e. ANN and SVM). The juxtaposition of fault classification of ANN and SVM method notify that proposed approach is much swiftly. Simultaneous identification of oil immersed power transformer incipient faults has never been identified formerly by using Multi-PSVM. The desired test analysis of experimental data from working transformers in the Northern Power Grid of India has been executed to present the robustness of evaluated incipient faults for large variation in loading and operational conditions perturbations.","PeriodicalId":206767,"journal":{"name":"2014 IEEE 6th India International Conference on Power Electronics (IICPE)","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125195586","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 : 2014-12-01DOI: 10.1109/IICPE.2014.7115863
S. Das, G. Narayanan, A. Tiwari
Aim of this paper is to study the variations in turn-on and turn-off switching energy losses in the IGBTs with device current at different DC link voltages and junction temperatures. The IGBT switching characteristics are obtained experimentally at various operating conditions, and turn-on and turn-off switching energy losses are determined. The relationship between the switching energy losses and the device currents are presented in mathematical form, which are derived from experimental data. Finally, a comparison has been made between calculated switching energy loss from linearized loss model and the derived expression from actual measured loss.
{"title":"Variation of IGBT switching energy loss with device current: An experimental investigation","authors":"S. Das, G. Narayanan, A. Tiwari","doi":"10.1109/IICPE.2014.7115863","DOIUrl":"https://doi.org/10.1109/IICPE.2014.7115863","url":null,"abstract":"Aim of this paper is to study the variations in turn-on and turn-off switching energy losses in the IGBTs with device current at different DC link voltages and junction temperatures. The IGBT switching characteristics are obtained experimentally at various operating conditions, and turn-on and turn-off switching energy losses are determined. The relationship between the switching energy losses and the device currents are presented in mathematical form, which are derived from experimental data. Finally, a comparison has been made between calculated switching energy loss from linearized loss model and the derived expression from actual measured loss.","PeriodicalId":206767,"journal":{"name":"2014 IEEE 6th India International Conference on Power Electronics (IICPE)","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129537136","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 : 2014-12-01DOI: 10.1109/IICPE.2014.7115834
P. Sharath Kumar, N. Vishwanathan, B. Murthy, D. Vijaya Bhaskar
This paper presents a class - D/E resonant inverter for multiple-load domestic induction cooking appliances. Most of the induction inverter configurations used in home appliances is based on single coil inverter. In these configurations, the vessel size cannot be more than induction coil size. The proposed configuration is suitable for any size of vessel and also can be used for multiple-loads. It operates with constant switching frequency and independent control of each load. The output power of each load can be controlled with asymmetrical duty cycle control technique for class-D configuration and with asymmetrical voltage cancellation control technique for class-E configuration. The proposed configuration and control techniques are simulated and experimentally tested with two loads. Simulation and experimental results are in good agreement. This configuration can be extended to multiple-loads.
{"title":"Class-D/E resonant inverter for multiple-load domestic induction cooking appliances","authors":"P. Sharath Kumar, N. Vishwanathan, B. Murthy, D. Vijaya Bhaskar","doi":"10.1109/IICPE.2014.7115834","DOIUrl":"https://doi.org/10.1109/IICPE.2014.7115834","url":null,"abstract":"This paper presents a class - D/E resonant inverter for multiple-load domestic induction cooking appliances. Most of the induction inverter configurations used in home appliances is based on single coil inverter. In these configurations, the vessel size cannot be more than induction coil size. The proposed configuration is suitable for any size of vessel and also can be used for multiple-loads. It operates with constant switching frequency and independent control of each load. The output power of each load can be controlled with asymmetrical duty cycle control technique for class-D configuration and with asymmetrical voltage cancellation control technique for class-E configuration. The proposed configuration and control techniques are simulated and experimentally tested with two loads. Simulation and experimental results are in good agreement. This configuration can be extended to multiple-loads.","PeriodicalId":206767,"journal":{"name":"2014 IEEE 6th India International Conference on Power Electronics (IICPE)","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126384889","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 : 2014-12-01DOI: 10.1109/IICPE.2014.7115783
N. Sandhu, S. Chanana
In wind energy conversion system the wind turbine captures the kinetic energy associate with the wind for the production of electricity with the help of generator. Performance of a wind turbine is dependent upon its operating conditions such as wind speed as well as its design parameters such as blade radius, blade pitch angle, weight etc. In the present paper, authors have made an attempt to develop a MATLAB/SIMULINK model of wind turbine. Model as developed is suitable to investigate its performance under constant as well as variable speed mode. Simulated results as obtained are found to be useful to predict the effect of wind speed and blade pitch on the performance of wind turbine under two operating modes.
{"title":"Behaviour of wind turbine under different operating modes","authors":"N. Sandhu, S. Chanana","doi":"10.1109/IICPE.2014.7115783","DOIUrl":"https://doi.org/10.1109/IICPE.2014.7115783","url":null,"abstract":"In wind energy conversion system the wind turbine captures the kinetic energy associate with the wind for the production of electricity with the help of generator. Performance of a wind turbine is dependent upon its operating conditions such as wind speed as well as its design parameters such as blade radius, blade pitch angle, weight etc. In the present paper, authors have made an attempt to develop a MATLAB/SIMULINK model of wind turbine. Model as developed is suitable to investigate its performance under constant as well as variable speed mode. Simulated results as obtained are found to be useful to predict the effect of wind speed and blade pitch on the performance of wind turbine under two operating modes.","PeriodicalId":206767,"journal":{"name":"2014 IEEE 6th India International Conference on Power Electronics (IICPE)","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124453150","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 : 2014-12-01DOI: 10.1109/IICPE.2014.7115849
Ajay Kumar, R. Dahiya
This Paper presents, the Load Frequency Control(LFC) of three area system controlled with the help of PID, Fuzzy Logic Controller(FLC), and Hybrid Fuzzy Tilt-Integral Derivative(HFTID) Controller. In this study two Non-Reheated Thermal and one Hydro system is connected by Tie-line. Fuzzy Logic Controller is Rule based which depends upon various inputs. It provides better performance and efficiency. Simulation is done using three Controllers for different inputs in MATLABSIMULINK software.
{"title":"Load Frequency Control of three area hydro thermal power system with HFTID Controller","authors":"Ajay Kumar, R. Dahiya","doi":"10.1109/IICPE.2014.7115849","DOIUrl":"https://doi.org/10.1109/IICPE.2014.7115849","url":null,"abstract":"This Paper presents, the Load Frequency Control(LFC) of three area system controlled with the help of PID, Fuzzy Logic Controller(FLC), and Hybrid Fuzzy Tilt-Integral Derivative(HFTID) Controller. In this study two Non-Reheated Thermal and one Hydro system is connected by Tie-line. Fuzzy Logic Controller is Rule based which depends upon various inputs. It provides better performance and efficiency. Simulation is done using three Controllers for different inputs in MATLABSIMULINK software.","PeriodicalId":206767,"journal":{"name":"2014 IEEE 6th India International Conference on Power Electronics (IICPE)","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124577515","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 : 2014-12-01DOI: 10.1109/IICPE.2014.7115805
A. Gupta, M. Joshi, V. Agarwal
Design and development details of a high power density, low cost, single phase transformerless PV inverter with reduced losses are reported. H-4 bridge topology is adopted to implement the proposed design where count of power devices is limited to four. One leg of the bridge operates at high switching frequency while the other leg operates at line frequency, this modulation technique reduces the switching losses. This also obviates the requirement of fast recovery anti parallel diodes across power devices for low frequency leg. Use of fewer devices and digital control (instead of analog control) has led to reduced cost and size. Switching and conduction losses are further reduced by using MOSFETs with very low on state resistance. A novel control scheme has been implemented to eliminate the DC offset at the output. A highly reliable over current and shoot-through protection is implemented through digital control. The digital control algorithm implemented enhances the reliability of operation at high power level. Optimal design of PCB and high frequency filters with SMD components contribute to high power density. A 3 kW prototype has been developed and tested for various reactive loads. All the analysis, simulation and experimental details of this work are presented.
{"title":"On the control and design issues of single phase transformerless inverters for photovoltaic applications","authors":"A. Gupta, M. Joshi, V. Agarwal","doi":"10.1109/IICPE.2014.7115805","DOIUrl":"https://doi.org/10.1109/IICPE.2014.7115805","url":null,"abstract":"Design and development details of a high power density, low cost, single phase transformerless PV inverter with reduced losses are reported. H-4 bridge topology is adopted to implement the proposed design where count of power devices is limited to four. One leg of the bridge operates at high switching frequency while the other leg operates at line frequency, this modulation technique reduces the switching losses. This also obviates the requirement of fast recovery anti parallel diodes across power devices for low frequency leg. Use of fewer devices and digital control (instead of analog control) has led to reduced cost and size. Switching and conduction losses are further reduced by using MOSFETs with very low on state resistance. A novel control scheme has been implemented to eliminate the DC offset at the output. A highly reliable over current and shoot-through protection is implemented through digital control. The digital control algorithm implemented enhances the reliability of operation at high power level. Optimal design of PCB and high frequency filters with SMD components contribute to high power density. A 3 kW prototype has been developed and tested for various reactive loads. All the analysis, simulation and experimental details of this work are presented.","PeriodicalId":206767,"journal":{"name":"2014 IEEE 6th India International Conference on Power Electronics (IICPE)","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130891194","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 : 2014-12-01DOI: 10.1109/IICPE.2014.7115850
Sangeeta DebBarman, T. Roy
This paper presents a new Pulse Width Modulation (PWM) technique for Z-source or Impedance Source Inverter (ZSI or ISI). The proposed technique is based on the Bus Clamping PWM (BCPWM) technique for Voltage Source Inverter (VSI). The effectiveness of the proposed technique is achieved by MATLAB simulation of a ZSI. It has been observed that the proposed technique gives better performances as compared to Conventional Space Vector PWM (CSVPWM) at high modulation index and at same switching frequency like reduction in load current ripple and reduction in voltage stress across the switches. Further the proposed technique ensures less switching loss as compared to CSVPWM at same carrier frequency.
{"title":"Advanced Pulse Width Modulation technique for Z-Source Inverter","authors":"Sangeeta DebBarman, T. Roy","doi":"10.1109/IICPE.2014.7115850","DOIUrl":"https://doi.org/10.1109/IICPE.2014.7115850","url":null,"abstract":"This paper presents a new Pulse Width Modulation (PWM) technique for Z-source or Impedance Source Inverter (ZSI or ISI). The proposed technique is based on the Bus Clamping PWM (BCPWM) technique for Voltage Source Inverter (VSI). The effectiveness of the proposed technique is achieved by MATLAB simulation of a ZSI. It has been observed that the proposed technique gives better performances as compared to Conventional Space Vector PWM (CSVPWM) at high modulation index and at same switching frequency like reduction in load current ripple and reduction in voltage stress across the switches. Further the proposed technique ensures less switching loss as compared to CSVPWM at same carrier frequency.","PeriodicalId":206767,"journal":{"name":"2014 IEEE 6th India International Conference on Power Electronics (IICPE)","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130994013","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 : 2014-12-01DOI: 10.1109/IICPE.2014.7115814
A. Guha, G. Narayanan
Inverter dead-time, which is meant to prevent shoot-through fault, causes harmonic distortion and change in the fundamental voltage in the inverter output. Typical dead-time compensation schemes ensure that the amplitude of the fundamental output current is as desired, and also improve the current waveform quality significantly. However, even with compensation, the motor line current waveform is observed to be distorted close to the current zero-crossings. The IGBT switching transition times being significantly longer at low currents than at high currents is an important reason for this zero-crossover distortion. Hence, this paper proposes an improved dead-time compensation scheme, which makes use of the measured IGBT switching transition times at low currents. Measured line current waveforms in a 2.2 kW induction motor drive with the proposed compensation scheme are compared against those with the conventional dead-time compensation scheme and without dead-time compensation. The experimental results on the motor drive clearly demonstrate the improvement in the line current waveform quality with the proposed method.
{"title":"An improved dead-time compensation scheme for voltage source inverters considering the device switching transition times","authors":"A. Guha, G. Narayanan","doi":"10.1109/IICPE.2014.7115814","DOIUrl":"https://doi.org/10.1109/IICPE.2014.7115814","url":null,"abstract":"Inverter dead-time, which is meant to prevent shoot-through fault, causes harmonic distortion and change in the fundamental voltage in the inverter output. Typical dead-time compensation schemes ensure that the amplitude of the fundamental output current is as desired, and also improve the current waveform quality significantly. However, even with compensation, the motor line current waveform is observed to be distorted close to the current zero-crossings. The IGBT switching transition times being significantly longer at low currents than at high currents is an important reason for this zero-crossover distortion. Hence, this paper proposes an improved dead-time compensation scheme, which makes use of the measured IGBT switching transition times at low currents. Measured line current waveforms in a 2.2 kW induction motor drive with the proposed compensation scheme are compared against those with the conventional dead-time compensation scheme and without dead-time compensation. The experimental results on the motor drive clearly demonstrate the improvement in the line current waveform quality with the proposed method.","PeriodicalId":206767,"journal":{"name":"2014 IEEE 6th India International Conference on Power Electronics (IICPE)","volume":"58 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127008264","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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