2015 IEEE 61st Holm Conference on Electrical Contacts (Holm)最新文献

{"title":"Deterioration mechanism of connectors used in long driven vehicles","authors":"S. Sawada, Y. Saitoh, K. Iida","doi":"10.1109/HOLM.2015.7355087","DOIUrl":"https://doi.org/10.1109/HOLM.2015.7355087","url":null,"abstract":"It is an important issue to investigate the deterioration state of connectors used in long driven vehicles in order to develop vehicle connectors. There are a few reports that investigated the deterioration state of connectors used in long driven vehicles in detail. Therefore, the deterioration state of a connector collected from a vehicle (driven for 8 years, 100,000km mileage) was investigated through the terminal resistance, the observation of connector surface, and oxidized abrasion powder in this study. Moreover, we investigated temperature environment and vibration status in the actual vehicle environment to identify the main factor of the connector deterioration. From these results, the deterioration of connectors used in long driven vehicles was estimated to be mainly fretting wear caused by vibration. In addition, the fretting cycle of fretting corrosion test in laboratory equivalent to fretting in 8 years 100,000km mileage driven was figured out by comparing the radius of the oxidized abrasion powder in fretting corrosion test with in corrected terminals.","PeriodicalId":448541,"journal":{"name":"2015 IEEE 61st Holm Conference on Electrical Contacts (Holm)","volume":"55 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125246749","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}

{"title":"Influence of opening velocity on various characteristics in DC high voltage Ag break arc","authors":"Kiyoshi Yoshida, K. Sawa, Kenji Suzuki, K. Takaya","doi":"10.1109/HOLM.2015.7355083","DOIUrl":"https://doi.org/10.1109/HOLM.2015.7355083","url":null,"abstract":"Recently, the demand to interrupt high DC voltage and current with electrical contacts has risen because of photovoltaic and electric vehicles (EV) applications. We produced the separating device that is able to open electrical contacts by the constant speed (1~200mm/s). The experiments had set the closed contact current to 10A constant under the source voltage DC200, 300, and 500V respectively. The arc voltage and current waveforms were observed. In addition, the video of the arc discharge light was recorded. To evaluate various characteristics of Ag break arc, arc duration time, contacts gap length, arc length and arc energy etc. were measured. As a result, it has been understood that the arc duration is in inverse proportion to opening velocity. This was similar to past research results. Further, arc energy is inversely proportional to opening velocity.","PeriodicalId":448541,"journal":{"name":"2015 IEEE 61st Holm Conference on Electrical Contacts (Holm)","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132962129","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}

{"title":"Validity of the voltage-temperature relation for contact elements in high power applications","authors":"M. Gatzsche, Nils Lucke, S. Grossmann, Tom Kufner, G. Freudiger","doi":"10.1109/HOLM.2015.7354951","DOIUrl":"https://doi.org/10.1109/HOLM.2015.7354951","url":null,"abstract":"With the voltage-temperature (V-T) relation, established by Kohlrausch in 1900, the electric potential distribution in an arbitrarily shaped, thermally insulated, current carrying conductor can be used to calculate the associated temperature distribution. An important application is the determination of the maximum temperature in electric contacts. However, researchers found deviations from the V-T relation for large contact systems when heat dissipation to the environment via radiation and convection becomes significant. The present investigation aims to verify the applicability of the V-T relation to typical spring-loaded contact elements for high power applications as for instance plug-in connections in highvoltage switchgear. A connector with a variable cooling system was continuously loaded with currents up to 6.7 kA to create a multitude of thermally symmetric and asymmetric steady-state operating points. Contact element temperatures were measured and compared to calculations with the V-T relation. When the load current varies over time, the spatially distributed heat capacity of the contact element and the adjacent conductors is charged or discharged to reach the electric-thermal steady-state for which the V-T relation applies. The transient temperature distribution may differ significantly, which is demonstrated by numerical calculations.","PeriodicalId":448541,"journal":{"name":"2015 IEEE 61st Holm Conference on Electrical Contacts (Holm)","volume":"124 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117011596","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}

{"title":"Electromechanical investigation into the influence of MWCNT height on the performance of Au/MWCNT composites for electrical contacts","authors":"A. Lewis, M. Down, Hong Liu, Liudi Jiang, J. McBride","doi":"10.1109/HOLM.2015.7355124","DOIUrl":"https://doi.org/10.1109/HOLM.2015.7355124","url":null,"abstract":"Au/MWCNT composites have been shown to be a useful contact material for electrical contacts. In this work we have investigated the influence of the MWCNT forest height on both the electrical and mechanical properties. Three heights of MWCNT forest have been investigated (30, 50 and 80 μm, all a sputtered 500 nm Au layer). It is shown that the electrical and mechanical behavior of the 30 and 50 μm composites is quite comparable, whereas there is a large change in the performance where the height is increased to 80 μm. As the MWCNT height is increased the effective hardness of the composite reduces which means that for a given contact pressure, the resultant contact area will be larger for taller MWCNT forests. A larger area combined with a higher resilience to impact is expected to result in larger lifetimes. A consequence of the softer composite with larger contact area is that the molten-metal bridge phenomenon has been shown to increase with MWCNT height. Experimental data is discussed to identify the optimum MWCNT height where the sputtered Au thickness is 500 nm. By analyzing the Au:MWCNT thickness ratio, it is possible to infer the optimum value for other thickness of Au. Combining this data with our model, it is also possible to estimate optimum thicknesses with other contact materials.","PeriodicalId":448541,"journal":{"name":"2015 IEEE 61st Holm Conference on Electrical Contacts (Holm)","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126082847","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}

{"title":"The contact force to prevent large area, closed, vacuum interrupter contacts from welding when passing high fault currents of up to 4 seconds duration","authors":"P. Slade","doi":"10.1109/HOLM.2015.7355080","DOIUrl":"https://doi.org/10.1109/HOLM.2015.7355080","url":null,"abstract":"An analysis is performed on data from an experiment to determine the closed contact force required to prevent the welding of closed, Cu-Cr contacts inside a vacuum interrupter passing 20kA (r.m.s) from 0.5s to 4s. It will be shown that the data can be explained if these closed contacts have more than one region of contact together with the heating of the contact's body during the passage of the current. The implication of this analysis for vacuum interrupters used in vacuum circuit breakers when required to stay closed during the passage of short circuit currents is discussed.","PeriodicalId":448541,"journal":{"name":"2015 IEEE 61st Holm Conference on Electrical Contacts (Holm)","volume":"58 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127305828","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}

{"title":"Experimental investigation of the electrical contact characteristics in Rolling Contact Connector","authors":"Junxing Chen, Fei Yang, K. Luo, Yi Wu, M. Rong","doi":"10.1109/HOLM.2015.7355103","DOIUrl":"https://doi.org/10.1109/HOLM.2015.7355103","url":null,"abstract":"Rolling Contact Connector (RCC) is a new technology utilized in high performance electric power transfer systems with one or more rotating interfaces, such as radars, satellites, wind generators, medical CT machines, etc. Rolling contacts components are used in the RCC instead of traditional sliding contact to transfer electrical power and/or signal. Since the requirement of the power transmission increasing in these years, the rolling electrical contact characteristics become more and more important for the long-life design of RCC. In this paper, a typical form of RCC is presented. A series of experimental work are carried out to investigate the rolling electrical contact characteristics during its life-time. The influence of a variety of factors on the electrical contact degradation behavior of RCC is analyzed under both vacuum and air environment. Based on the surface morphology and elemental composition changes in the contact zone, which is assessed by field emission scanning electron microscope (FE-SEM) and energy dispersive X-ray (EDX), the mechanism of rolling electrical contact degradation is discussed.","PeriodicalId":448541,"journal":{"name":"2015 IEEE 61st Holm Conference on Electrical Contacts (Holm)","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128290645","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}

{"title":"Novel materials solutions and simulations for nanoelectromechanical switches","authors":"F. Streller, G. E. Wabiszewski, D. Durham, Fan Yang, Jing Yang, Y. Qi, D. Srolovitz, A. Rappe, R. Carpick","doi":"10.1109/HOLM.2015.7355122","DOIUrl":"https://doi.org/10.1109/HOLM.2015.7355122","url":null,"abstract":"Nanoelectromechanical (NEM) switches are a candidate to replace solid-state transistors due to their low power consumption. However, the reliability of the contact interface limits the commercialization of NEM switches, since for practical purposes, the electrical contact should be able to physically open and close up to a quadrillion (1015) times without failing due to adhesion (by sticking shut) or contamination (reducing switch conductivity). These failure mechanisms are not well understood, and materials that exhibit the needed performance have not yet been demonstrated. This study presents the development of platinum silicide (PtxSi) as a promising NEM switch contact material. Using controlled solid-state diffusion of thin films of amorphous silicon and platinum, PtxSi was formed over a range of stoichiometries (1≤x≤3). The platinum-rich silicide phase (Pt3Si) may be a particularly ideal contact material for NEM switches due to its combination of mechanical robustness with metal-like conductivity. We then present a novel, high-throughput contact material screening method for NEM contact materials based on atomic force microscopy (AFM) that enables billions of contact cycles in laboratory timeframes for arbitrary material pairs. Self-mated Pt contacts showed more than three orders-of-magnitude increase in contact resistance after 2·109 cycles due to the growth of insulating tribopolymer. Finally, we present density functional theory (DFT) and molecular dynamics (MD) based studies to understand tribopolymer formation and growth. These calculations show that irreversible stress-induced polymerization processes are strongly affected by the ability of the molecule to displace laterally. Additionally, lower interaction energies between the model organic molecules and the PtxSi surface compared to Pt are found. This combination of experimental and theoretical methods in the framework of a materials genome effort aims to ultimately lead to accelerated discovery of suitable contact materials for NEM switches and to their commercialization.","PeriodicalId":448541,"journal":{"name":"2015 IEEE 61st Holm Conference on Electrical Contacts (Holm)","volume":"252 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128479651","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}

{"title":"Influences of Contact opening speeds in the range of 0.5 to 200 mm/s on break arc behaviors of AgSnO2 contacts in DC conditions","authors":"M. Hasegawa, Hiroya Sonobe, Nanami Ohkawa","doi":"10.1109/HOLM.2015.7355091","DOIUrl":"https://doi.org/10.1109/HOLM.2015.7355091","url":null,"abstract":"Break operations of DC inductive (L=20mH) currents in the range from about 1 to 10A at 14V were conducted with AgSnO2 contact pairs under different contact opening speeds from 0.5 to 200mm/s in air. Break arc voltage waveforms were observed, and total break arc durations and metallic phase arc durations were measured. After the experiments, averages for the total arc duration and the metallic phase arc duration were calculated at each condition. With load current of about 3A or more, the average total break arc durations showed shortening tendencies with increases in the contact opening speeds, but only in the middle range of the tested speed levels. With slower and faster speed levels, the arc shortening tendencies became less significant. Even in the middle speed range, the average total break arc durations were not in inverse proportion to the contact opening speeds. However, the metallic phase arc duration characteristics were found to show inversely proportional relationships with the contact opening speeds under certain operating conditions. Thus, the contact opening speeds exhibit clear influences mainly on metallic phases of break arc discharges. It seems the inductive component in the load circuit provided a contact gap with sufficient energy to prevent quick arc extinctions. Further experiments were also done in a DC resistive load circuit for comparison.","PeriodicalId":448541,"journal":{"name":"2015 IEEE 61st Holm Conference on Electrical Contacts (Holm)","volume":"157 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116362806","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}

{"title":"If holm had used a Scanning Tunneling Microscope: What the nanoscientists are teaching us about electrical contacts","authors":"G. Dorsey","doi":"10.1109/HOLM.2015.7355076","DOIUrl":"https://doi.org/10.1109/HOLM.2015.7355076","url":null,"abstract":"The invention in the 1980s of the Atomic Force and the Scanning Tunneling Microscopes and widespread use of these and other tools since then has led to an explosion in research into the characterization of contact interfaces at the atomic and molecular level, i.e., on the nanoscale. This paper reviews this research and points to areas where this nanoscale research has a significant impact of our understanding of electrical contacts. Areas of consideration include lubrication, surface films, contact resistance, adhesion, and friction.","PeriodicalId":448541,"journal":{"name":"2015 IEEE 61st Holm Conference on Electrical Contacts (Holm)","volume":"86 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121369746","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}

{"title":"Electric characteristics and contact area features of melting when making and breaking contacts","authors":"N. Wakatsuki, Tomohiro Watanabe","doi":"10.1109/HOLM.2015.7355077","DOIUrl":"https://doi.org/10.1109/HOLM.2015.7355077","url":null,"abstract":"We studied the contact current after Vc=Um of electric contacts during `initial arc'. Using the transient current switch circuit (diodes, resistor and capacitor parallel to the contacts), the melting phenomena of cross-rod electrodes of 0.5mm in diameter were separately observed from arc discharge. Measurement of electric characteristics and observation of the contact area features by laser microscope were able to confirm the existence of conduction current due to the remaining metal contact. This would means that conductive currents flow just after Vc=Um, arcing currents join them one by one, and only the arcing current flows at the last.","PeriodicalId":448541,"journal":{"name":"2015 IEEE 61st Holm Conference on Electrical Contacts (Holm)","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128499075","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}