Pub Date : 2020-09-30DOI: 10.1109/HLM49214.2020.9307908
Zhimin Xie, Xingwen Li, Jing Wang, Silei Chen
With the rapid development of dc system, the residual current in dc system has become an urgent problem to be solved. However, the type B residual current devices (RCD) for ac systems could not be directly used in dc systems. The ac residual current caused by distributed capacitance and the rectifier seriously interferes with the accurate detection of the dc residual current. A detection simulation model of dc residual current based on magnetic modulation was established. The authors also proposed detection algorithms based on Kalman filter and moving average filter separately. The experimental results showed that the proposed model and detection algorithms were effective. They could detect the residual current in the dc system under ac interferences.
{"title":"Study of Measurement and Detection Algorithm of LVDC Residual Current","authors":"Zhimin Xie, Xingwen Li, Jing Wang, Silei Chen","doi":"10.1109/HLM49214.2020.9307908","DOIUrl":"https://doi.org/10.1109/HLM49214.2020.9307908","url":null,"abstract":"With the rapid development of dc system, the residual current in dc system has become an urgent problem to be solved. However, the type B residual current devices (RCD) for ac systems could not be directly used in dc systems. The ac residual current caused by distributed capacitance and the rectifier seriously interferes with the accurate detection of the dc residual current. A detection simulation model of dc residual current based on magnetic modulation was established. The authors also proposed detection algorithms based on Kalman filter and moving average filter separately. The experimental results showed that the proposed model and detection algorithms were effective. They could detect the residual current in the dc system under ac interferences.","PeriodicalId":268345,"journal":{"name":"2020 IEEE 66th Holm Conference on Electrical Contacts and Intensive Course (HLM)","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126671967","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 : 2020-09-30DOI: 10.1109/HLM49214.2020.9307833
J. McBride, H. Liu
The application of a structured and rough surface, and the effect the roughness has on contact resistance is considered in an electrical contact application. The surfaces are designed to enhance roughness, with an amplitude parameter (Sq, RMS) of 0.1-1 µm. An established finite element model of a bi-layered rough contact surface is extended to include the pre-processing and analysis of a model rough surface. The application is a gold-coated multi-walled carbon nanotube composite (Au/CNT), designed as a solution for electrical contacts in low current switching applications. To determine the contact resistance for these surfaces, a preliminary step is required to determine the effective resistivity.Model surfaces are compared to a measured rough surface, where the sample length of the surface and the sensor interaction with the measured surface are identified as key parameters. The finite element model provides an output of the interactions between a hemi-spherical ball and the rough Au/CNT surface, with the results shown as a map of the points of contact as a function of the applied force (mN). An automated method of post processing the image data is used to determine the number of contact points and the best fitting radius of the contact area. It is shown that the contact resistance increases with surface roughness (Sq).
{"title":"The Relationship between Contact Resistance and Roughness (Sq) of a Bi-layered Surface using a Finite Element Model","authors":"J. McBride, H. Liu","doi":"10.1109/HLM49214.2020.9307833","DOIUrl":"https://doi.org/10.1109/HLM49214.2020.9307833","url":null,"abstract":"The application of a structured and rough surface, and the effect the roughness has on contact resistance is considered in an electrical contact application. The surfaces are designed to enhance roughness, with an amplitude parameter (Sq, RMS) of 0.1-1 µm. An established finite element model of a bi-layered rough contact surface is extended to include the pre-processing and analysis of a model rough surface. The application is a gold-coated multi-walled carbon nanotube composite (Au/CNT), designed as a solution for electrical contacts in low current switching applications. To determine the contact resistance for these surfaces, a preliminary step is required to determine the effective resistivity.Model surfaces are compared to a measured rough surface, where the sample length of the surface and the sensor interaction with the measured surface are identified as key parameters. The finite element model provides an output of the interactions between a hemi-spherical ball and the rough Au/CNT surface, with the results shown as a map of the points of contact as a function of the applied force (mN). An automated method of post processing the image data is used to determine the number of contact points and the best fitting radius of the contact area. It is shown that the contact resistance increases with surface roughness (Sq).","PeriodicalId":268345,"journal":{"name":"2020 IEEE 66th Holm Conference on Electrical Contacts and Intensive Course (HLM)","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114422877","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 : 2020-09-30DOI: 10.1109/HLM49214.2020.9307906
N. Tang, Hongyu Xu, Xiaofeng Bai, Xingwen Li
Overheating is one of the key factors affecting the normal service life of switch cabinets. Therefore, it is of great significance to find out methods to reduce the temperature rise of the switch cabinet. In this paper, based on a 400V low-voltage switchgear, a three-dimensional simulation model is established using the electromagnetic-thermal-fluid multi-physics coupling method. Under the conditions of simulating natural convection, considering eddy current effects, proximity effects, and skin effects, heat transfer methods such as thermal conduction, thermal convection, and thermal radiation are comprehensively used to calculate and analyze the thermal distribution characteristics of the distribution cabinet shells and three-phase current-carrying conductors. Moreover, a temperature-rise experiment is performed to verify the feasibility and accuracy of the electromagnetic-thermal-fluid multi-physics coupling method and the accuracy and effectiveness of the calculation model under the current simulation conditions. In addition, in order to reduce the temperature rise of the cabinet, A strategy for optimizing the switchgear is proposed, and the heat distribution characteristics of the optimized model is calculated using the multi-physics coupling method. The results show that the temperature rise of the switch cabinets of the scheme has been reduced in different degrees, which effectively solves the overheating problem of the switch cabinet.
{"title":"Analysis of Thermal Characteristics of Switch Cabinet with Multi-Physics Field Coupling Method","authors":"N. Tang, Hongyu Xu, Xiaofeng Bai, Xingwen Li","doi":"10.1109/HLM49214.2020.9307906","DOIUrl":"https://doi.org/10.1109/HLM49214.2020.9307906","url":null,"abstract":"Overheating is one of the key factors affecting the normal service life of switch cabinets. Therefore, it is of great significance to find out methods to reduce the temperature rise of the switch cabinet. In this paper, based on a 400V low-voltage switchgear, a three-dimensional simulation model is established using the electromagnetic-thermal-fluid multi-physics coupling method. Under the conditions of simulating natural convection, considering eddy current effects, proximity effects, and skin effects, heat transfer methods such as thermal conduction, thermal convection, and thermal radiation are comprehensively used to calculate and analyze the thermal distribution characteristics of the distribution cabinet shells and three-phase current-carrying conductors. Moreover, a temperature-rise experiment is performed to verify the feasibility and accuracy of the electromagnetic-thermal-fluid multi-physics coupling method and the accuracy and effectiveness of the calculation model under the current simulation conditions. In addition, in order to reduce the temperature rise of the cabinet, A strategy for optimizing the switchgear is proposed, and the heat distribution characteristics of the optimized model is calculated using the multi-physics coupling method. The results show that the temperature rise of the switch cabinets of the scheme has been reduced in different degrees, which effectively solves the overheating problem of the switch cabinet.","PeriodicalId":268345,"journal":{"name":"2020 IEEE 66th Holm Conference on Electrical Contacts and Intensive Course (HLM)","volume":"2009 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130218887","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 : 2020-09-30DOI: 10.1109/HLM49214.2020.9307919
R. Martens, Suvrat Bhargava, John Consoli, Chad Morgan, Daniel Hubbard
Fundamental literature and electromagnetic simulations show DC contact resistance values on ground connections of up to several ohms can be tolerated with little impact on signal transmission. This indicates traditional DC contact resistance failure criterion on the order of milliohms may be overly conservative for high-speed ground contacts, enabling consideration of lower cost electroplated contact finishes. Electromagnetic simulations at the connector level validated that signal integrity is intact with ground contact resistance values up to 1 ohm and beyond. Gold and a non-noble tin-nickel alloy exhibiting higher, yet stable electrical contact resistance as compared to typical contact finishes were evaluated using industry standard accelerated testing. Results indicate that with a relaxed DC contact resistance failure criterion, the lower cost ground tin-nickel alloy finish can deliver reliable signal integrity performance over the lifetime of a typical high-speed connector product.
{"title":"Contact Finish Considerations for High-Frequency Ground Connections","authors":"R. Martens, Suvrat Bhargava, John Consoli, Chad Morgan, Daniel Hubbard","doi":"10.1109/HLM49214.2020.9307919","DOIUrl":"https://doi.org/10.1109/HLM49214.2020.9307919","url":null,"abstract":"Fundamental literature and electromagnetic simulations show DC contact resistance values on ground connections of up to several ohms can be tolerated with little impact on signal transmission. This indicates traditional DC contact resistance failure criterion on the order of milliohms may be overly conservative for high-speed ground contacts, enabling consideration of lower cost electroplated contact finishes. Electromagnetic simulations at the connector level validated that signal integrity is intact with ground contact resistance values up to 1 ohm and beyond. Gold and a non-noble tin-nickel alloy exhibiting higher, yet stable electrical contact resistance as compared to typical contact finishes were evaluated using industry standard accelerated testing. Results indicate that with a relaxed DC contact resistance failure criterion, the lower cost ground tin-nickel alloy finish can deliver reliable signal integrity performance over the lifetime of a typical high-speed connector product.","PeriodicalId":268345,"journal":{"name":"2020 IEEE 66th Holm Conference on Electrical Contacts and Intensive Course (HLM)","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133013733","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 : 2020-09-30DOI: 10.1109/HLM49214.2020.9307843
Marion Kubler-Riedinger, J. Bauchire, D. Hong, G. Déplaude, P. Joyeux
The contact point in modular protective devices is the place where the current lines are concentrated. This phenomenon leads to the contact point heating or even melting, with a risk of sticking. Sticking can prevent the product from opening if the opening force is not sufficient to detach the contacts, causing serious damage to the electrical installation and to persons. It is therefore essential to avoid any welding of the contacts. That is why a test bench was designed and built in order to determine the temperature rise and the conditions leading to static melting. The current used had a waveform and an amplitude similar to that of the short-circuit current.This paper presents electrical measurements coupled with microscopic measurements of contact surfaces: 3D optical imaging (x500), and electron imaging (x150 to 2000) for surface topology and chemical distribution. This allowed us to better interpret the electrical behavior of the contact point. Investigations were performed according to several parameters: current amplitude passing through the contact point and contact force preset via a spring. Based on the results, the influence of these parameters on the contact voltage and on the state of the contact surface was characterized.
{"title":"Electrical and Morphological Investigations of Electrical Contacts used in Low-Voltage Circuit-Breakers","authors":"Marion Kubler-Riedinger, J. Bauchire, D. Hong, G. Déplaude, P. Joyeux","doi":"10.1109/HLM49214.2020.9307843","DOIUrl":"https://doi.org/10.1109/HLM49214.2020.9307843","url":null,"abstract":"The contact point in modular protective devices is the place where the current lines are concentrated. This phenomenon leads to the contact point heating or even melting, with a risk of sticking. Sticking can prevent the product from opening if the opening force is not sufficient to detach the contacts, causing serious damage to the electrical installation and to persons. It is therefore essential to avoid any welding of the contacts. That is why a test bench was designed and built in order to determine the temperature rise and the conditions leading to static melting. The current used had a waveform and an amplitude similar to that of the short-circuit current.This paper presents electrical measurements coupled with microscopic measurements of contact surfaces: 3D optical imaging (x500), and electron imaging (x150 to 2000) for surface topology and chemical distribution. This allowed us to better interpret the electrical behavior of the contact point. Investigations were performed according to several parameters: current amplitude passing through the contact point and contact force preset via a spring. Based on the results, the influence of these parameters on the contact voltage and on the state of the contact surface was characterized.","PeriodicalId":268345,"journal":{"name":"2020 IEEE 66th Holm Conference on Electrical Contacts and Intensive Course (HLM)","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123860925","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 : 2020-09-30DOI: 10.1109/HLM49214.2020.9307880
J. McBride, T. Bull
A metallic coated carbon nanotube surface, developed for use in a micro-electromechanical (MEMS) switching device, is investigated for performance, when switching 4 VDC, with current levels between 10 to 600 mA; with the objective of understanding the upper limits of the surface performance. The surface used is a Gold Coated (500 nm), forest of multi-walled carbon nanotubes (50 μm), referred to as Au/CNT. The surface has been previously investigated for endurance at low current levels of 4 μA, to characterize the cold switching performance over 4 billion switching cycles and tested in a cantilever MEMs test system with 10 mA (hot switching) over 0.5 billion cycles. This investigation studies the current loading level with a focus on the transient voltages during the opening process. The investigation is undertaken using a piezoelectric (PZT) actuator, as part of an in-situ test apparatus (ICE). Results are compared to the transient voltage on a reference carbon nanotube surface without the gold coating, under the same switching conditions. The results for the Au/CNT surface show that the voltage transients are dominated by molten metal bridge phenomena up to 300 mA above which a previously unreported switching transient is observed. The higher current levels (300 to 600 mA) are shown to puncture the gold surface after 10’s of switching cycles exposing the CNT. Under this condition the exposed CNT become conductive and thermally decompose (pyrolyze).
{"title":"Breakdown Voltage in Multi Walled Carbon- Nanotubes during Low Voltage (4 V) DC Switching","authors":"J. McBride, T. Bull","doi":"10.1109/HLM49214.2020.9307880","DOIUrl":"https://doi.org/10.1109/HLM49214.2020.9307880","url":null,"abstract":"A metallic coated carbon nanotube surface, developed for use in a micro-electromechanical (MEMS) switching device, is investigated for performance, when switching 4 VDC, with current levels between 10 to 600 mA; with the objective of understanding the upper limits of the surface performance. The surface used is a Gold Coated (500 nm), forest of multi-walled carbon nanotubes (50 μm), referred to as Au/CNT. The surface has been previously investigated for endurance at low current levels of 4 μA, to characterize the cold switching performance over 4 billion switching cycles and tested in a cantilever MEMs test system with 10 mA (hot switching) over 0.5 billion cycles. This investigation studies the current loading level with a focus on the transient voltages during the opening process. The investigation is undertaken using a piezoelectric (PZT) actuator, as part of an in-situ test apparatus (ICE). Results are compared to the transient voltage on a reference carbon nanotube surface without the gold coating, under the same switching conditions. The results for the Au/CNT surface show that the voltage transients are dominated by molten metal bridge phenomena up to 300 mA above which a previously unreported switching transient is observed. The higher current levels (300 to 600 mA) are shown to puncture the gold surface after 10’s of switching cycles exposing the CNT. Under this condition the exposed CNT become conductive and thermally decompose (pyrolyze).","PeriodicalId":268345,"journal":{"name":"2020 IEEE 66th Holm Conference on Electrical Contacts and Intensive Course (HLM)","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122543028","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 : 2020-09-30DOI: 10.1109/HLM49214.2020.9307893
S. Gortschakow, D. Gonzalez, M. Boening, D. Uhrlandt, S. Boening
Powder metallurgical manufactured Cu/Cr electrodes made from materials with different Cr morphology have been studied under the AC current load up to 6.5 kA. Special attention was paid to the appearance of various anode modes. Arc dynamics has been acquired by high-speed camera. NIR spectroscopy was used for determination of the time- and space-resolved anode surface temperature. Broadband absorption spectroscopy was applied for determination of the vapor density with respect to different anode modes. Existence ranges of various anode modes, as well as the results of anode surface temperature and Cr I density measurements for two electrode materials are presented and discussed.
{"title":"Observed Characteristics of Vacuum Arc Anode Phenomena Regarding the Influence of Electrode Material","authors":"S. Gortschakow, D. Gonzalez, M. Boening, D. Uhrlandt, S. Boening","doi":"10.1109/HLM49214.2020.9307893","DOIUrl":"https://doi.org/10.1109/HLM49214.2020.9307893","url":null,"abstract":"Powder metallurgical manufactured Cu/Cr electrodes made from materials with different Cr morphology have been studied under the AC current load up to 6.5 kA. Special attention was paid to the appearance of various anode modes. Arc dynamics has been acquired by high-speed camera. NIR spectroscopy was used for determination of the time- and space-resolved anode surface temperature. Broadband absorption spectroscopy was applied for determination of the vapor density with respect to different anode modes. Existence ranges of various anode modes, as well as the results of anode surface temperature and Cr I density measurements for two electrode materials are presented and discussed.","PeriodicalId":268345,"journal":{"name":"2020 IEEE 66th Holm Conference on Electrical Contacts and Intensive Course (HLM)","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123293505","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 : 2020-09-30DOI: 10.1109/HLM49214.2020.9307907
Jianning Yin, Qian Wang, Xingwen Li, Tian Tian, Hongwu Liu
Low voltage circuit breaker is a crucial component for protecting power distribution system. The breaking capability is the key parameter of low voltage circuit breaker. Outgassing material is commonly used to improve the breaking capability in low voltage circuit breakers. Therefore, the evaluation method of outgassing characteristic of outgassing material is critical. This paper focus on the experimental study on outgassing properties evaluation of polymers. The detachable experimental prototype is designed and produced. In order to ensure that the arc burns in the middle of the quenching chamber, the electrode is designed in a triangular shape. Outgassing material is arranged around the arc quenching chamber. The copper wire is used to ignite arc in experiment. The arc voltage, arc current, pressure of quenching chamber, ablation mass of outgassing material, insulation resistance after arcing are obtained. The effects of different polymers on arc characteristic at various current levels are comparatively analyzed. The metrics for evaluating the properties of polymers are proposed. It provides a theoretical basis for the selection of outgassing polymers.
{"title":"Experimental Evaluation of Outgassing Characteristics of Polymers on Air Arc Behavior","authors":"Jianning Yin, Qian Wang, Xingwen Li, Tian Tian, Hongwu Liu","doi":"10.1109/HLM49214.2020.9307907","DOIUrl":"https://doi.org/10.1109/HLM49214.2020.9307907","url":null,"abstract":"Low voltage circuit breaker is a crucial component for protecting power distribution system. The breaking capability is the key parameter of low voltage circuit breaker. Outgassing material is commonly used to improve the breaking capability in low voltage circuit breakers. Therefore, the evaluation method of outgassing characteristic of outgassing material is critical. This paper focus on the experimental study on outgassing properties evaluation of polymers. The detachable experimental prototype is designed and produced. In order to ensure that the arc burns in the middle of the quenching chamber, the electrode is designed in a triangular shape. Outgassing material is arranged around the arc quenching chamber. The copper wire is used to ignite arc in experiment. The arc voltage, arc current, pressure of quenching chamber, ablation mass of outgassing material, insulation resistance after arcing are obtained. The effects of different polymers on arc characteristic at various current levels are comparatively analyzed. The metrics for evaluating the properties of polymers are proposed. It provides a theoretical basis for the selection of outgassing polymers.","PeriodicalId":268345,"journal":{"name":"2020 IEEE 66th Holm Conference on Electrical Contacts and Intensive Course (HLM)","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124287246","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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