Pub Date : 2016-10-01DOI: 10.1109/HOLM.2016.7780013
M. Spahr, S. Kreitlein, R. Haas, A. Jaumann, T. Gläßel, S. Spreng, J. Franke
Through customers' desire for an individualization of vehicles, new electronics-supported functions are continuously being added. The automobile wiring harness must meet these requests without any further increase of weight and volume. The basic trend towards a modular vehicular design, the continually growing complexity of production and assembly processes, supports the use of flexible flat cables (FFCs) in a hybrid wiring system architecture. For an integral approach, it is also important to develop corresponding alternatives for electrically contacting FFCs with the components. To that end, the process-conditional, one-sided accessibility of FFCs represents a particular challenge. Motivated by these challenges, the Institute FAPS has developed an automated assembly system of FFCs and a new concept for a flexible electric contacting system enabling direct electrical contacting of installed FFCs. To qualify this new contacting method, time and cost consuming climatic tests according to different specifications of the automotive industry have to be carried out. Here, the use of analytic accelerated test-models can predict the failure of electronic contacts subject to the load case. The scope of this approach is the application and comparison of three different accelerated test-methods (Arrhenius, Coffin-Manson and Norris-Landzberg) to the novel contacting method. Firstly climatic tests were performed at different elevated temperatures and from the test data, a lifetime prognosis was derived. Secondly all three models were validated with further climatic testing to determine the possible field application of accelerated test methods.
{"title":"Application and comparison of analytic accelerated test-models for lifetime prediction of a novel contacting method","authors":"M. Spahr, S. Kreitlein, R. Haas, A. Jaumann, T. Gläßel, S. Spreng, J. Franke","doi":"10.1109/HOLM.2016.7780013","DOIUrl":"https://doi.org/10.1109/HOLM.2016.7780013","url":null,"abstract":"Through customers' desire for an individualization of vehicles, new electronics-supported functions are continuously being added. The automobile wiring harness must meet these requests without any further increase of weight and volume. The basic trend towards a modular vehicular design, the continually growing complexity of production and assembly processes, supports the use of flexible flat cables (FFCs) in a hybrid wiring system architecture. For an integral approach, it is also important to develop corresponding alternatives for electrically contacting FFCs with the components. To that end, the process-conditional, one-sided accessibility of FFCs represents a particular challenge. Motivated by these challenges, the Institute FAPS has developed an automated assembly system of FFCs and a new concept for a flexible electric contacting system enabling direct electrical contacting of installed FFCs. To qualify this new contacting method, time and cost consuming climatic tests according to different specifications of the automotive industry have to be carried out. Here, the use of analytic accelerated test-models can predict the failure of electronic contacts subject to the load case. The scope of this approach is the application and comparison of three different accelerated test-methods (Arrhenius, Coffin-Manson and Norris-Landzberg) to the novel contacting method. Firstly climatic tests were performed at different elevated temperatures and from the test data, a lifetime prognosis was derived. Secondly all three models were validated with further climatic testing to determine the possible field application of accelerated test methods.","PeriodicalId":117231,"journal":{"name":"2016 IEEE 62nd Holm Conference on Electrical Contacts (Holm)","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128271924","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 : 2016-10-01DOI: 10.1109/HOLM.2016.7780000
C. Zhai, D. Hanaor, G. Proust, Y. Gan
Electrical networks of randomly distributed resistors, capacitors, and inductors have been observed to exhibit intrinsic electrical characteristics that show power law behavior with respect to the frequency of the electrical signal applied. To examine these scaling laws, we present an experimental investigation of the stress-dependent electrical properties of randomly packed spheres of stainless steel, subjected to various conditions of compressive force. We considered two types of spheres exhibiting different dimensions, in order to have different inter-particle forces, which govern interfacial electrical properties, at a given stress. The frequency-dependent conductance and impedance of packed beds are found to demonstrate power-law relationships within a certain range of frequency. The absolute value of the exponent of the observed power function varies with the applied stress. The capacitive-to-inductive phase transition was observed as load increased, and was found to depend on the applied stress level and surface-to-volume ratio. The approach of equivalent network circuit was developed to describe the variation of macroscopic impedance at various frequencies. This study provides an insight into the characteristic electrical behaviors of conductive granular materials.
{"title":"Stress-dependent frequency response of conductive granular materials","authors":"C. Zhai, D. Hanaor, G. Proust, Y. Gan","doi":"10.1109/HOLM.2016.7780000","DOIUrl":"https://doi.org/10.1109/HOLM.2016.7780000","url":null,"abstract":"Electrical networks of randomly distributed resistors, capacitors, and inductors have been observed to exhibit intrinsic electrical characteristics that show power law behavior with respect to the frequency of the electrical signal applied. To examine these scaling laws, we present an experimental investigation of the stress-dependent electrical properties of randomly packed spheres of stainless steel, subjected to various conditions of compressive force. We considered two types of spheres exhibiting different dimensions, in order to have different inter-particle forces, which govern interfacial electrical properties, at a given stress. The frequency-dependent conductance and impedance of packed beds are found to demonstrate power-law relationships within a certain range of frequency. The absolute value of the exponent of the observed power function varies with the applied stress. The capacitive-to-inductive phase transition was observed as load increased, and was found to depend on the applied stress level and surface-to-volume ratio. The approach of equivalent network circuit was developed to describe the variation of macroscopic impedance at various frequencies. This study provides an insight into the characteristic electrical behaviors of conductive granular materials.","PeriodicalId":117231,"journal":{"name":"2016 IEEE 62nd Holm Conference on Electrical Contacts (Holm)","volume":"98 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133300566","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 : 2016-10-01DOI: 10.1109/HOLM.2016.7780007
J. Rodriguez
The study of the arc interruption in low voltage circuit breakers has been a topic of interest by many researchers. This phenomenon is a consequence of high current flowing into a circuit breaker, the circuit is forced to open and an electrical arc appears between the contacts when they separate from each other. This electrical arc is formed by electromagnetic plasma, consequence of different phenomena interacting to achieve their extinction in a very short time. The phenomena have been studied in the past, leading to the design of different experiments to study the interruption process of the electrical arc. This work will present a method to illustrate the movement of the arc based on experimental results at high current interruptions in a volumetric perspective. This new way to represent the arc will help the engineers to evaluate the behavior of the arc inside of the arc chamber; this will provide a better way to estimate the displacement and expulsion of the arc from the arc chamber.
{"title":"Experimental method to obtain a volumetric representation of the arc splitting process in MCCB","authors":"J. Rodriguez","doi":"10.1109/HOLM.2016.7780007","DOIUrl":"https://doi.org/10.1109/HOLM.2016.7780007","url":null,"abstract":"The study of the arc interruption in low voltage circuit breakers has been a topic of interest by many researchers. This phenomenon is a consequence of high current flowing into a circuit breaker, the circuit is forced to open and an electrical arc appears between the contacts when they separate from each other. This electrical arc is formed by electromagnetic plasma, consequence of different phenomena interacting to achieve their extinction in a very short time. The phenomena have been studied in the past, leading to the design of different experiments to study the interruption process of the electrical arc. This work will present a method to illustrate the movement of the arc based on experimental results at high current interruptions in a volumetric perspective. This new way to represent the arc will help the engineers to evaluate the behavior of the arc inside of the arc chamber; this will provide a better way to estimate the displacement and expulsion of the arc from the arc chamber.","PeriodicalId":117231,"journal":{"name":"2016 IEEE 62nd Holm Conference on Electrical Contacts (Holm)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130990570","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 : 2016-10-01DOI: 10.1109/HOLM.2016.7780002
Silei Chen, Xingwen Li
In recent years, increasing fire accidents in the photovoltaic (PV) system by PV series arc fault cause huge economic losses and pose great threats to its operating safety. However, increasing PV voltage and maximum power point track (MPPT) from the inverter during arc ignition make PV series arc fault complex to be detected. This paper aims at providing a joint detection method to arc fault circuit interrupters (AFCI) serving for smart micro grid. In this paper, two methods to bring PV series arc fault into the PV system have been recorded by intensified charge-coupled device (ICCD). By introducing PV series arc fault into the system in due time, normal and fault electric signals have been acquired under different imitated working conditions. Statistic method from time domain and short time Fourier transformation (STFT) from time-frequency domain are chosen to diagnose this kind of fault. A detection variable from each method has been proposed to recognize it accurately. A relatively satisfying joint algorithm based on two proposed detection variables has been put forward to prevent unwanted nuisance trips from system transient process. To fit constantly varying electric signals in PV system, this detection algorithm also adopts dynamic threshold value.
{"title":"PV series arc fault recognition under different working conditions with joint detection method","authors":"Silei Chen, Xingwen Li","doi":"10.1109/HOLM.2016.7780002","DOIUrl":"https://doi.org/10.1109/HOLM.2016.7780002","url":null,"abstract":"In recent years, increasing fire accidents in the photovoltaic (PV) system by PV series arc fault cause huge economic losses and pose great threats to its operating safety. However, increasing PV voltage and maximum power point track (MPPT) from the inverter during arc ignition make PV series arc fault complex to be detected. This paper aims at providing a joint detection method to arc fault circuit interrupters (AFCI) serving for smart micro grid. In this paper, two methods to bring PV series arc fault into the PV system have been recorded by intensified charge-coupled device (ICCD). By introducing PV series arc fault into the system in due time, normal and fault electric signals have been acquired under different imitated working conditions. Statistic method from time domain and short time Fourier transformation (STFT) from time-frequency domain are chosen to diagnose this kind of fault. A detection variable from each method has been proposed to recognize it accurately. A relatively satisfying joint algorithm based on two proposed detection variables has been put forward to prevent unwanted nuisance trips from system transient process. To fit constantly varying electric signals in PV system, this detection algorithm also adopts dynamic threshold value.","PeriodicalId":117231,"journal":{"name":"2016 IEEE 62nd Holm Conference on Electrical Contacts (Holm)","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117072851","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 : 2016-10-01DOI: 10.1109/HOLM.2016.7780030
M. Muñoz, Hai-Ching Chen, J. Hernández
This paper reports the investigation of tin plating as a potential alternate to silver plating on plug in line terminal connections for low voltage low amp miniature circuit breakers. The plug in line terminals are typically connected on the enclosure interior bus bars and clamped with a spring clip. The substrate material of the line terminal was a copper alloy. The line terminals with both, tin and silver plating, were investigated on tin plated aluminum and bare copper bus bars. The connections were examined by cycling 50 Amps ac, one hour on and one hour off for 2,100 cycles in an ambient temperature of 25°C. The examined parameters were bulk temperature and voltage drop. SEM observations have been made for both, tin and silver plating, after the current cycling. Additionally, the plating deterioration on the contact spots was measured for oxygen and copper contents by EDX analysis. The analysis results indicated much higher contents of oxygen and copper on the tin plated connectors than the silver plated connectors which is consistent with the connector plating deterioration and fretting that was observed with the SEM.
{"title":"Tin plating investigation as a potential alternate to silver plating in plug in connection for low voltage low amp miniature circuit breakers","authors":"M. Muñoz, Hai-Ching Chen, J. Hernández","doi":"10.1109/HOLM.2016.7780030","DOIUrl":"https://doi.org/10.1109/HOLM.2016.7780030","url":null,"abstract":"This paper reports the investigation of tin plating as a potential alternate to silver plating on plug in line terminal connections for low voltage low amp miniature circuit breakers. The plug in line terminals are typically connected on the enclosure interior bus bars and clamped with a spring clip. The substrate material of the line terminal was a copper alloy. The line terminals with both, tin and silver plating, were investigated on tin plated aluminum and bare copper bus bars. The connections were examined by cycling 50 Amps ac, one hour on and one hour off for 2,100 cycles in an ambient temperature of 25°C. The examined parameters were bulk temperature and voltage drop. SEM observations have been made for both, tin and silver plating, after the current cycling. Additionally, the plating deterioration on the contact spots was measured for oxygen and copper contents by EDX analysis. The analysis results indicated much higher contents of oxygen and copper on the tin plated connectors than the silver plated connectors which is consistent with the connector plating deterioration and fretting that was observed with the SEM.","PeriodicalId":117231,"journal":{"name":"2016 IEEE 62nd Holm Conference on Electrical Contacts (Holm)","volume":"91 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126960279","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 : 2016-10-01DOI: 10.1109/HOLM.2016.7780003
Haomiao Yuan, Jian Song, Vitali Schinow
Coating thickness, normal force and the geometry of sample configuration are important design parameters for contacts. The influence of these parameters on the fretting behavior of the tin coated electrical contacts has been recently studied. It was concluded by some researchers that the tin coating thickness and load have a larger effect on contact resistance, while the other parameters, namely temperature, humidity, amplitude, frequency, geometry of sample configuration and aged/brand-new samples, are less critical [1]. However, according to our experiments, the geometry of sample configuration, namely the radius of the sphere part at the sphere/plane configuration, also has great influence on the fretting behavior reflected by the change of contact resistance. In this paper, a further investigation was conducted on some of the parameters in [1]. It was found that the radius of the sphere parts at the sphere/plane configuration is also a critical parameter with regard to the fretting corrosion. The fretting behavior is complicated under a lower level force, since increasing force on the one hand assists the penetration of the oxide layer, and on the other hand increases the wear. At the high level force of 4 N, a longer lifetime can be obtained.
{"title":"Fretting corrosion of tin coated electrical contacts: The influence of normal force, coating thickness and geometry of sample configuration","authors":"Haomiao Yuan, Jian Song, Vitali Schinow","doi":"10.1109/HOLM.2016.7780003","DOIUrl":"https://doi.org/10.1109/HOLM.2016.7780003","url":null,"abstract":"Coating thickness, normal force and the geometry of sample configuration are important design parameters for contacts. The influence of these parameters on the fretting behavior of the tin coated electrical contacts has been recently studied. It was concluded by some researchers that the tin coating thickness and load have a larger effect on contact resistance, while the other parameters, namely temperature, humidity, amplitude, frequency, geometry of sample configuration and aged/brand-new samples, are less critical [1]. However, according to our experiments, the geometry of sample configuration, namely the radius of the sphere part at the sphere/plane configuration, also has great influence on the fretting behavior reflected by the change of contact resistance. In this paper, a further investigation was conducted on some of the parameters in [1]. It was found that the radius of the sphere parts at the sphere/plane configuration is also a critical parameter with regard to the fretting corrosion. The fretting behavior is complicated under a lower level force, since increasing force on the one hand assists the penetration of the oxide layer, and on the other hand increases the wear. At the high level force of 4 N, a longer lifetime can be obtained.","PeriodicalId":117231,"journal":{"name":"2016 IEEE 62nd Holm Conference on Electrical Contacts (Holm)","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127881906","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 : 2016-10-01DOI: 10.1109/HOLM.2016.7779999
Qiuyan Jin, Jinchun Gao, G. Xie, G. Flowers, Rui Ji
Radio frequency (RF) connectors may exhibit nonlinear characteristics in the higher levels of transmission power, which causes passive intermodulation (PIM) to seriously degrade the performance of the communication system, even when the connectors are pristine. Accordingly, it is important to investigate the PIM induced by nonlinear effects of RF connectors. In the present work, an equivalent circuit model for a contact surface of coaxial connector was analyzed and a nonlinear physical mechanism was investigated to explain the sources of the nonlinearities. Simulations were developed and evaluated to demonstrate that surface parameters such as roughness, contact pressure and film thickness affects the change of the PIM. Moreover, a traditional nonlinear current-voltage (I-V) model was developed to describe the characteristics of third-order harmonics with input power and power ratios. Based on the two-tone testing procedure, a series of experiments were also conducted to evaluate third-order IM products. The power dependence and the effect of two input power ratios were studied experimentally and the influence of connector degradation on nonlinear effects was also investigated. A prediction of third-order IM powers by the nonlinear mathematical I-V models was verified, with the testing results showing good consistency with the behavior predicted by the models.
{"title":"A study of the passive intermodulation induced by nonlinear characteristics of RF connectors","authors":"Qiuyan Jin, Jinchun Gao, G. Xie, G. Flowers, Rui Ji","doi":"10.1109/HOLM.2016.7779999","DOIUrl":"https://doi.org/10.1109/HOLM.2016.7779999","url":null,"abstract":"Radio frequency (RF) connectors may exhibit nonlinear characteristics in the higher levels of transmission power, which causes passive intermodulation (PIM) to seriously degrade the performance of the communication system, even when the connectors are pristine. Accordingly, it is important to investigate the PIM induced by nonlinear effects of RF connectors. In the present work, an equivalent circuit model for a contact surface of coaxial connector was analyzed and a nonlinear physical mechanism was investigated to explain the sources of the nonlinearities. Simulations were developed and evaluated to demonstrate that surface parameters such as roughness, contact pressure and film thickness affects the change of the PIM. Moreover, a traditional nonlinear current-voltage (I-V) model was developed to describe the characteristics of third-order harmonics with input power and power ratios. Based on the two-tone testing procedure, a series of experiments were also conducted to evaluate third-order IM products. The power dependence and the effect of two input power ratios were studied experimentally and the influence of connector degradation on nonlinear effects was also investigated. A prediction of third-order IM powers by the nonlinear mathematical I-V models was verified, with the testing results showing good consistency with the behavior predicted by the models.","PeriodicalId":117231,"journal":{"name":"2016 IEEE 62nd Holm Conference on Electrical Contacts (Holm)","volume":"136 8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134266141","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 : 2016-10-01DOI: 10.1109/HOLM.2016.7780016
You Jiaxin, Wang Ruichao, Liang Huimin, Bao Longqing, W. Hongjian
The enclosed isolated phase bus-bar (EIPB), which is the first power transmission part of synchronous generator output, plays an important role in the stability of the system in short circuit conditions. The section shape of bus-bar has very big relation with the dynamic stability of EIPB. In this paper, an analytical calculation model of EIPB is analyzed firstly. Based on the analytical model, the finite element method (FEM) and its model is established. The traditional rectangle bus-bar and circle bus-bar are calculated using this model. The performances under different conditions are discussed: with enclosures and without enclosures, AC. Taking the circle section EIPB for example, the relationship between the ratio of transfer current and the electrodynamic force safety are also discussed.
{"title":"Research on the calculation methods of enclosed isolated phase bus-bar in short-circuit condition","authors":"You Jiaxin, Wang Ruichao, Liang Huimin, Bao Longqing, W. Hongjian","doi":"10.1109/HOLM.2016.7780016","DOIUrl":"https://doi.org/10.1109/HOLM.2016.7780016","url":null,"abstract":"The enclosed isolated phase bus-bar (EIPB), which is the first power transmission part of synchronous generator output, plays an important role in the stability of the system in short circuit conditions. The section shape of bus-bar has very big relation with the dynamic stability of EIPB. In this paper, an analytical calculation model of EIPB is analyzed firstly. Based on the analytical model, the finite element method (FEM) and its model is established. The traditional rectangle bus-bar and circle bus-bar are calculated using this model. The performances under different conditions are discussed: with enclosures and without enclosures, AC. Taking the circle section EIPB for example, the relationship between the ratio of transfer current and the electrodynamic force safety are also discussed.","PeriodicalId":117231,"journal":{"name":"2016 IEEE 62nd Holm Conference on Electrical Contacts (Holm)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115630421","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 : 2016-10-01DOI: 10.1109/HOLM.2016.7780036
Xue Zhou, Qingnan Li, G. Zhai, Liwen Chen
Latched-type relays used in smart Watt-hour meters need to carry a current some ten times higher than its rated value when a short circuit happens in its testing region. The Holm's repelling force and the static welding are two major challenges faced to the contact system leading by the short circuit current. Movable springs of those relays are usually metal stacks in “V” shape for providing not only additional force to overcome the Holm's repelling force but also tangential motion to break the static welding. Transient electro-thermal coupling analysis was carried out to a typical contact system under a variety of short currents with different lasting time to evaluate the highest temperature rise for the metal stack. Then, thermo-structural model was used to predict, firstly the expansion and elongation degree of the metal stack when the contacting point was set to be free (without welding) and secondly the tangential force exerted on the contacting point when it was set to be fixed (with welding).
{"title":"Over-current performance of movable springs of a latched-type relay used in Watt-hour meters","authors":"Xue Zhou, Qingnan Li, G. Zhai, Liwen Chen","doi":"10.1109/HOLM.2016.7780036","DOIUrl":"https://doi.org/10.1109/HOLM.2016.7780036","url":null,"abstract":"Latched-type relays used in smart Watt-hour meters need to carry a current some ten times higher than its rated value when a short circuit happens in its testing region. The Holm's repelling force and the static welding are two major challenges faced to the contact system leading by the short circuit current. Movable springs of those relays are usually metal stacks in “V” shape for providing not only additional force to overcome the Holm's repelling force but also tangential motion to break the static welding. Transient electro-thermal coupling analysis was carried out to a typical contact system under a variety of short currents with different lasting time to evaluate the highest temperature rise for the metal stack. Then, thermo-structural model was used to predict, firstly the expansion and elongation degree of the metal stack when the contacting point was set to be free (without welding) and secondly the tangential force exerted on the contacting point when it was set to be fixed (with welding).","PeriodicalId":117231,"journal":{"name":"2016 IEEE 62nd Holm Conference on Electrical Contacts (Holm)","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130188389","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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