The partial discharge (PD) is the main cause of the insulation failure in power transformers. Localization of the partial discharge source in the transformer effectively and precisely has a very important meaning in the insulation maintenance. The acoustic emission(AE) method has attracted researchers' attention because AE sensors have excellent ability to resist electromagnetic interference and they are convenient to be installed. Many researchers use an array of multiple AE sensors to collect PD signals and use the time difference between the signals to localize the PD source. However, if the sensor arrangement is unreasonable, it will inevitably introduce a huge error in time difference estimation. In this paper, the propagation characteristics of AE signals and the basic principles of time-difference-of-arrival (TDOA) methods are briefly introduced. After that, this paper describes how to set up a transformer physical model proposes a method of optimizing the arrangement of ultrasonic sensor arrays to better localize the partial discharge power in transformers. The algorithm is used to optimize the sensor array on two planes of a 35kV transformer.
{"title":"Methodology of Searching the Best AE Sensor Array to localize PD sources in Power Transformer","authors":"Shao-Rui Qin, Yan-Bo Wang, G. Ding, Taiyun Zhu, Jianlin Li, Guanjun Zhang","doi":"10.1109/CMD.2018.8535845","DOIUrl":"https://doi.org/10.1109/CMD.2018.8535845","url":null,"abstract":"The partial discharge (PD) is the main cause of the insulation failure in power transformers. Localization of the partial discharge source in the transformer effectively and precisely has a very important meaning in the insulation maintenance. The acoustic emission(AE) method has attracted researchers' attention because AE sensors have excellent ability to resist electromagnetic interference and they are convenient to be installed. Many researchers use an array of multiple AE sensors to collect PD signals and use the time difference between the signals to localize the PD source. However, if the sensor arrangement is unreasonable, it will inevitably introduce a huge error in time difference estimation. In this paper, the propagation characteristics of AE signals and the basic principles of time-difference-of-arrival (TDOA) methods are briefly introduced. After that, this paper describes how to set up a transformer physical model proposes a method of optimizing the arrangement of ultrasonic sensor arrays to better localize the partial discharge power in transformers. The algorithm is used to optimize the sensor array on two planes of a 35kV transformer.","PeriodicalId":6529,"journal":{"name":"2018 Condition Monitoring and Diagnosis (CMD)","volume":"254 1","pages":"1-5"},"PeriodicalIF":0.0,"publicationDate":"2018-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80711576","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 : 2018-09-01DOI: 10.1109/CMD.2018.8535792
M. Anis
With increasing investments being made by the Provincial Government in KSA's Eastern Province on irrigation water distribution projects, more focus is being placed on finding ways to reduce expenditure and restore the lost performance of irrigation assets due to planned or un-planned overhauls. This article presents a modeling approach to improve the repair schedule at the local water pump stations with an aim of minimizing total life-cycle cost of the pumps while maintaining eco-friendly standards. The case study used focuses on a Sanitary Wastewater Treatment Plant (SWTP) having centrifugal pumps running in parallel configuration to pump water from tanks to service reservoir. The opted methodology considers a realistic set of assumptions with the type of data available to identify four main parameters for maintenance decisions- the Hydraulic Model, Operation Model, Deterioration Model and Optimization Model. A hydraulic mode for the pumping system has been defined with performance measures like head-flow, power-flow and system curves and is used to compliment the deterioration model, which predicts the drop in pump performance with continuous use. Operational inputs such as the production schedules, pump schedules, duty specification, hydraulic output etc. are combined with deterioration mechanisms, namely the wear ring and internal surface deterioration, to identify an optimization model- an optimal pump overhaul schedule. While the hydraulic model is explained numerically using equations to approximate solutions, the optimization model is discussed as a linear integer programming problem using heuristics. Mathematically computed solutions to the models are finally applied to a system of three pump stations to forecast an appropriate number of overhauls for each pump station over the next four years with the subsequent costing involved. Thus, the described approach serves as a model-based decision support system tool (DSS) to assist planning engineers and asset maintenance managers in crucial pump overhaul planning and budgeting decisions.
{"title":"Identifying a Mathematical Model to Optimize Pump Maintenance Planning Decisions - A Case of Irrigation Asset Management in K.S.A","authors":"M. Anis","doi":"10.1109/CMD.2018.8535792","DOIUrl":"https://doi.org/10.1109/CMD.2018.8535792","url":null,"abstract":"With increasing investments being made by the Provincial Government in KSA's Eastern Province on irrigation water distribution projects, more focus is being placed on finding ways to reduce expenditure and restore the lost performance of irrigation assets due to planned or un-planned overhauls. This article presents a modeling approach to improve the repair schedule at the local water pump stations with an aim of minimizing total life-cycle cost of the pumps while maintaining eco-friendly standards. The case study used focuses on a Sanitary Wastewater Treatment Plant (SWTP) having centrifugal pumps running in parallel configuration to pump water from tanks to service reservoir. The opted methodology considers a realistic set of assumptions with the type of data available to identify four main parameters for maintenance decisions- the Hydraulic Model, Operation Model, Deterioration Model and Optimization Model. A hydraulic mode for the pumping system has been defined with performance measures like head-flow, power-flow and system curves and is used to compliment the deterioration model, which predicts the drop in pump performance with continuous use. Operational inputs such as the production schedules, pump schedules, duty specification, hydraulic output etc. are combined with deterioration mechanisms, namely the wear ring and internal surface deterioration, to identify an optimization model- an optimal pump overhaul schedule. While the hydraulic model is explained numerically using equations to approximate solutions, the optimization model is discussed as a linear integer programming problem using heuristics. Mathematically computed solutions to the models are finally applied to a system of three pump stations to forecast an appropriate number of overhauls for each pump station over the next four years with the subsequent costing involved. Thus, the described approach serves as a model-based decision support system tool (DSS) to assist planning engineers and asset maintenance managers in crucial pump overhaul planning and budgeting decisions.","PeriodicalId":6529,"journal":{"name":"2018 Condition Monitoring and Diagnosis (CMD)","volume":"61 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2018-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88493866","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}
The space charges accumulation between HVDC cable and accessory insulation will accelerate degradation and breakdown of the cable system, endanger the safety of the power grid. As is known that conductivity mismatch of cross-linked polyethylene (XLPE) and ethylene-propylene-diene terpolymer (EPDM) is the main reason for the charges accumulation in the interface. To investigate the influence of EPDM conductivity on the interface behaviors of XLPE/EPDM, In this paper, high field conductivity of two kind of EPDM and XLPE were tested at −5 kV/mm, −10 kV/mm, −20 kV/mm, −30 kV/mm, −40 kV/mm, −50 kV/mm and −60 kV/mm, and the space charges distribution of XLPE/EPDM interface was tested by pressure wave propagation (PWP) at −10kV/mm, −20kV/mm and −30kV/mm. It is shown that, when the conductivity of XLPE is lower than EPDM, the interface charge is positive; On the contrary, when the conductivity of XLPE is higher than EPDM, the interface charge is negative, and the interface charges density increases as the electric field rise. The experimental results are consistent with the interface charge density calculated based on the Maxwell-Wagner theory.
{"title":"Interface Charge Behaviors between XLPE and EPDM with Different Conductivity","authors":"Dong Li, Zhien Zhu, Liming Yang, Hao Zeng, K. Gao, Lixin Xu","doi":"10.1109/CMD.2018.8535642","DOIUrl":"https://doi.org/10.1109/CMD.2018.8535642","url":null,"abstract":"The space charges accumulation between HVDC cable and accessory insulation will accelerate degradation and breakdown of the cable system, endanger the safety of the power grid. As is known that conductivity mismatch of cross-linked polyethylene (XLPE) and ethylene-propylene-diene terpolymer (EPDM) is the main reason for the charges accumulation in the interface. To investigate the influence of EPDM conductivity on the interface behaviors of XLPE/EPDM, In this paper, high field conductivity of two kind of EPDM and XLPE were tested at −5 kV/mm, −10 kV/mm, −20 kV/mm, −30 kV/mm, −40 kV/mm, −50 kV/mm and −60 kV/mm, and the space charges distribution of XLPE/EPDM interface was tested by pressure wave propagation (PWP) at −10kV/mm, −20kV/mm and −30kV/mm. It is shown that, when the conductivity of XLPE is lower than EPDM, the interface charge is positive; On the contrary, when the conductivity of XLPE is higher than EPDM, the interface charge is negative, and the interface charges density increases as the electric field rise. The experimental results are consistent with the interface charge density calculated based on the Maxwell-Wagner theory.","PeriodicalId":6529,"journal":{"name":"2018 Condition Monitoring and Diagnosis (CMD)","volume":"13 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2018-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75570468","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 : 2018-09-01DOI: 10.1109/CMD.2018.8535857
Toshihiro Takahashi
Partial discharge (PD) measurement is a powerful technique for the insulation diagnosis and precise asset management of electric power apparatus. However, PD occurs sometimes not continuously, rather with very low repetition rate in its inception stage. In that case, it is difficult in on-site PD measurement and diagnosis, because the pulses of very low repetition rate are difficult to produce any finger print such as phase resolved PD pattern (PRPD pattern). On the contrary, the continuously generated pulse signals obtained at the on-site PD measurement sometimes do not come from PD generated at the internal electrical insulation layer but outside of the apparatus such as a surface of the bushing, an edge of a metallic part of the apparatus which is installed near the objective apparatus. These signals coming not from the intended apparatus sometimes leads incorrect diagnostic results. Thus, the discrimination methodology of PD signals occurring in the intended apparatus is important for the accurate PD measurement and diagnosis. This paper discusses the discrimination methodology for the PD measurement at cable terminations and joints.
{"title":"Methodology of on-site Precise Partial Discharge Measurement for Cable Terminations and Joints","authors":"Toshihiro Takahashi","doi":"10.1109/CMD.2018.8535857","DOIUrl":"https://doi.org/10.1109/CMD.2018.8535857","url":null,"abstract":"Partial discharge (PD) measurement is a powerful technique for the insulation diagnosis and precise asset management of electric power apparatus. However, PD occurs sometimes not continuously, rather with very low repetition rate in its inception stage. In that case, it is difficult in on-site PD measurement and diagnosis, because the pulses of very low repetition rate are difficult to produce any finger print such as phase resolved PD pattern (PRPD pattern). On the contrary, the continuously generated pulse signals obtained at the on-site PD measurement sometimes do not come from PD generated at the internal electrical insulation layer but outside of the apparatus such as a surface of the bushing, an edge of a metallic part of the apparatus which is installed near the objective apparatus. These signals coming not from the intended apparatus sometimes leads incorrect diagnostic results. Thus, the discrimination methodology of PD signals occurring in the intended apparatus is important for the accurate PD measurement and diagnosis. This paper discusses the discrimination methodology for the PD measurement at cable terminations and joints.","PeriodicalId":6529,"journal":{"name":"2018 Condition Monitoring and Diagnosis (CMD)","volume":"26 1","pages":"1-5"},"PeriodicalIF":0.0,"publicationDate":"2018-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75425923","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 : 2018-09-01DOI: 10.1109/CMD.2018.8535602
Guanglei Huang, W. Cao, Xiaolei Xie, Zilong Li, Zhe Li, G. Sheng
The classification of partial discharge is of significance to diagnose the defects in high voltage cable systems. To improve the insulation defect classification accuracy at DC cross linked polyethylene(XLPE) cables, a new method used for PD images classification based on convolutional deep belief network (CDBN) is proposed in this paper. Firstly, four kinds of defects in XLPE cables are designed and tested under DC voltage. The q-Δt-n image is constructed based on PD signal collected by HFCT. Then the diagnostic CDBN model is constructed to extract the high-level detailed feature of q-Δt-n images with Gaussian visible units. Finally, classification experiments with CDBN, deep belief network(DBN), support vector machine(SVM) and backpropagation neural network(BPNN) is conducted. The experiment results show that the proposed method has higher classification accuracy of insulation defect diagnosis.
{"title":"Classification of Partial Discharge Images within DC XLPE Cables Based on Convolutional Deep Belief Network","authors":"Guanglei Huang, W. Cao, Xiaolei Xie, Zilong Li, Zhe Li, G. Sheng","doi":"10.1109/CMD.2018.8535602","DOIUrl":"https://doi.org/10.1109/CMD.2018.8535602","url":null,"abstract":"The classification of partial discharge is of significance to diagnose the defects in high voltage cable systems. To improve the insulation defect classification accuracy at DC cross linked polyethylene(XLPE) cables, a new method used for PD images classification based on convolutional deep belief network (CDBN) is proposed in this paper. Firstly, four kinds of defects in XLPE cables are designed and tested under DC voltage. The q-Δt-n image is constructed based on PD signal collected by HFCT. Then the diagnostic CDBN model is constructed to extract the high-level detailed feature of q-Δt-n images with Gaussian visible units. Finally, classification experiments with CDBN, deep belief network(DBN), support vector machine(SVM) and backpropagation neural network(BPNN) is conducted. The experiment results show that the proposed method has higher classification accuracy of insulation defect diagnosis.","PeriodicalId":6529,"journal":{"name":"2018 Condition Monitoring and Diagnosis (CMD)","volume":"40 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2018-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90299715","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 : 2018-09-01DOI: 10.1109/CMD.2018.8535655
Charbel Antoun
This paper aims to explore the various failure modes associated with High Voltage Circuit Breakers and Power Transformers within transmission and subtransmission electricity networks and identify the online monitoring requirements to ensure effective early detection of issues. This would enable system operators to act appropriately to prevent unexpected failures. These requirements in the context of the capabilities and limitations in currently available Online Monitoring Technologies will also be discussed.
{"title":"High Voltage Circuit Breaker and Power Transformer Failure Modes and Their Detection","authors":"Charbel Antoun","doi":"10.1109/CMD.2018.8535655","DOIUrl":"https://doi.org/10.1109/CMD.2018.8535655","url":null,"abstract":"This paper aims to explore the various failure modes associated with High Voltage Circuit Breakers and Power Transformers within transmission and subtransmission electricity networks and identify the online monitoring requirements to ensure effective early detection of issues. This would enable system operators to act appropriately to prevent unexpected failures. These requirements in the context of the capabilities and limitations in currently available Online Monitoring Technologies will also be discussed.","PeriodicalId":6529,"journal":{"name":"2018 Condition Monitoring and Diagnosis (CMD)","volume":"10 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2018-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88863079","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 : 2018-09-01DOI: 10.1109/CMD.2018.8535828
Feng Ji, Qing Xu, Zhengqi Tian, Jin Bao
Considering the problems that Black box testing method for watt-hour meter cannot implement branch path traversal of the watt-hour meter software, and can't provide EEPROM data error tolerance evaluation of the watt-hour meter, also including the fact that watt-hour meter data storage unit EEPROM preserves running parameters of watt-hour meters, this paper proposes a new type of watt-hour meter white-box testing method based on EEPROM read and write. The new test method rewrites the parameters in EEPROM, which can implement branch path traversal of the watt-hour meter software, and avoid the branches path missing of the black box test. At the same time, the new test method can realize the fault tolerance evaluation of watt-hour meter software. Through the construction and integration of the new test platform, the watt-hour meter software can be tested automatically by the white-box test method, thus the test efficiency is greatly improved. As this method is applicable to the reliability test of the watt-hour meter, it can obtain better economic benefits compared with the black box testing method. The implementation of the new method in this paper have a certain reference value as to improve the reliability and fault tolerance of the watt-hour meter.
{"title":"A New White Box Test Method Applying to Watt-hour Meter Based on EEPROM Read and Write Data","authors":"Feng Ji, Qing Xu, Zhengqi Tian, Jin Bao","doi":"10.1109/CMD.2018.8535828","DOIUrl":"https://doi.org/10.1109/CMD.2018.8535828","url":null,"abstract":"Considering the problems that Black box testing method for watt-hour meter cannot implement branch path traversal of the watt-hour meter software, and can't provide EEPROM data error tolerance evaluation of the watt-hour meter, also including the fact that watt-hour meter data storage unit EEPROM preserves running parameters of watt-hour meters, this paper proposes a new type of watt-hour meter white-box testing method based on EEPROM read and write. The new test method rewrites the parameters in EEPROM, which can implement branch path traversal of the watt-hour meter software, and avoid the branches path missing of the black box test. At the same time, the new test method can realize the fault tolerance evaluation of watt-hour meter software. Through the construction and integration of the new test platform, the watt-hour meter software can be tested automatically by the white-box test method, thus the test efficiency is greatly improved. As this method is applicable to the reliability test of the watt-hour meter, it can obtain better economic benefits compared with the black box testing method. The implementation of the new method in this paper have a certain reference value as to improve the reliability and fault tolerance of the watt-hour meter.","PeriodicalId":6529,"journal":{"name":"2018 Condition Monitoring and Diagnosis (CMD)","volume":"35 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2018-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78742178","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 : 2018-09-01DOI: 10.1109/CMD.2018.8535666
N. Phloymuk, P. Nimsanong, N. Phumipunepon, S. Potivejkul, T. Wiangtong, N. Pattanadech
the aim of this paper is to describe the dielectric loss tangent (tan δ) behaviors of the stator winding insulation of the 14.5 MVA 11kV synchronous machine from 2014–2017. This machine is still operated up to now. The tan δ values at different test voltages was measured and recorded. It was found that the sharp increase in tan δ values gave the sign of a significant degree of contamination and damage on the insulation surface which was proved by inspection. From the investigation the tan δ measurements is one of the effective ways to monitor and evaluate the insulation conditions of the stator insulation. The analysis and discussion of the existed problem of the synchronous machine are also included in this paper.
{"title":"The Dissipation Factor (tan δ) Monitoring of A Stator Winding Insulation of A Synchronous Machine","authors":"N. Phloymuk, P. Nimsanong, N. Phumipunepon, S. Potivejkul, T. Wiangtong, N. Pattanadech","doi":"10.1109/CMD.2018.8535666","DOIUrl":"https://doi.org/10.1109/CMD.2018.8535666","url":null,"abstract":"the aim of this paper is to describe the dielectric loss tangent (tan δ) behaviors of the stator winding insulation of the 14.5 MVA 11kV synchronous machine from 2014–2017. This machine is still operated up to now. The tan δ values at different test voltages was measured and recorded. It was found that the sharp increase in tan δ values gave the sign of a significant degree of contamination and damage on the insulation surface which was proved by inspection. From the investigation the tan δ measurements is one of the effective ways to monitor and evaluate the insulation conditions of the stator insulation. The analysis and discussion of the existed problem of the synchronous machine are also included in this paper.","PeriodicalId":6529,"journal":{"name":"2018 Condition Monitoring and Diagnosis (CMD)","volume":"127 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2018-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85724572","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 : 2018-09-01DOI: 10.1109/CMD.2018.8535906
Kyu-Hoon Park, Ho-Yun Lee, M. Asif, Bang-wook Lee
As the multi-terminal HVDC systems are expanding, the needs for a HVDC circuit breaker is being enhanced to eliminate the adverse effects of a single pole fault on the whole system. However, there are challenges of dc interrupting that is due to the absence of the natural current zero point and the large rate of fault current (di / dt), which results in enormous interrupting energy. Therefore, the suitable circuit breaker topology that satisfy dc interrupting requirements have been widely studied. The passive resonance circuit breaker (PRCB) is one of the circuit breaker topologies that have been considered for HVDC system, and it is necessary to investigate the arc characteristics occurring in the main circuit breaker during opening operation. In this paper, a dc current source that generates a current pulse using semiconductor device IGBT switch and pre-charged capacitor was modeled, and Mayr black box model was used for analysis of arc characteristics. Unlike the conventional current source that generates the dc arc current using the L and C, the new current source can be arbitrarily selected for the current shape and the current slope without hardware modification and was used for measuring the steady state and transient state voltage-current characteristics of the switching arc. The black box Mayr model parameter values were calculated elaborately through the enhanced current source and the Levenberg-Marquardt Algorithm (LMA) widely used in the optimization technique was applied to the Mayr model to optimize the parameter values.
{"title":"Investigation of Arc Behavior in HVDC LC Resonance Circuit Breaker Using Flexible Pulsed DC-Source","authors":"Kyu-Hoon Park, Ho-Yun Lee, M. Asif, Bang-wook Lee","doi":"10.1109/CMD.2018.8535906","DOIUrl":"https://doi.org/10.1109/CMD.2018.8535906","url":null,"abstract":"As the multi-terminal HVDC systems are expanding, the needs for a HVDC circuit breaker is being enhanced to eliminate the adverse effects of a single pole fault on the whole system. However, there are challenges of dc interrupting that is due to the absence of the natural current zero point and the large rate of fault current (di / dt), which results in enormous interrupting energy. Therefore, the suitable circuit breaker topology that satisfy dc interrupting requirements have been widely studied. The passive resonance circuit breaker (PRCB) is one of the circuit breaker topologies that have been considered for HVDC system, and it is necessary to investigate the arc characteristics occurring in the main circuit breaker during opening operation. In this paper, a dc current source that generates a current pulse using semiconductor device IGBT switch and pre-charged capacitor was modeled, and Mayr black box model was used for analysis of arc characteristics. Unlike the conventional current source that generates the dc arc current using the L and C, the new current source can be arbitrarily selected for the current shape and the current slope without hardware modification and was used for measuring the steady state and transient state voltage-current characteristics of the switching arc. The black box Mayr model parameter values were calculated elaborately through the enhanced current source and the Levenberg-Marquardt Algorithm (LMA) widely used in the optimization technique was applied to the Mayr model to optimize the parameter values.","PeriodicalId":6529,"journal":{"name":"2018 Condition Monitoring and Diagnosis (CMD)","volume":"93 1","pages":"1-5"},"PeriodicalIF":0.0,"publicationDate":"2018-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85792651","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 : 2018-09-01DOI: 10.1109/CMD.2018.8535625
Natsumi Sato, Kotaro Suzuki, Ushio Chiba, H. Miyake, Y. Tanaka, T. Okumura, S. Kawakita, M. Takahashi, K. Koga
The dielectric characteristics of the surface material of the spacecraft, such as secondary electron emission (SEE) and photoelectron emission (PE), are required for high reliability of spacecraft generation. Those materials are deteriorated due to radioactive rays irradiation on orbit. Those values may be changed from the situation. When we want to estimate surface changing at the end of life (EOL) of satellite with accuracy, we need to give values of PE and SEE at EOL situation. In this report, we irradiated the proton beam to insulating materials and measured PE on the aged sample. We examined the relationship between the irradiation dose and PE.
{"title":"Photoelectron Emission on Polyimide Films Irradiated by Proton","authors":"Natsumi Sato, Kotaro Suzuki, Ushio Chiba, H. Miyake, Y. Tanaka, T. Okumura, S. Kawakita, M. Takahashi, K. Koga","doi":"10.1109/CMD.2018.8535625","DOIUrl":"https://doi.org/10.1109/CMD.2018.8535625","url":null,"abstract":"The dielectric characteristics of the surface material of the spacecraft, such as secondary electron emission (SEE) and photoelectron emission (PE), are required for high reliability of spacecraft generation. Those materials are deteriorated due to radioactive rays irradiation on orbit. Those values may be changed from the situation. When we want to estimate surface changing at the end of life (EOL) of satellite with accuracy, we need to give values of PE and SEE at EOL situation. In this report, we irradiated the proton beam to insulating materials and measured PE on the aged sample. We examined the relationship between the irradiation dose and PE.","PeriodicalId":6529,"journal":{"name":"2018 Condition Monitoring and Diagnosis (CMD)","volume":"19 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2018-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88618819","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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