Pub Date : 2010-11-01DOI: 10.1109/IAS.2010.5616747
M. Nayel
This paper studies those parameters affecting the shielding angle of the lightning rod (Franklin Rod) above very tall buildings. It is recommended that the shielding angle of the lightning rod is about 45o ~ 60o. The downward lightning leader is modeled by using discrete line charge to consider the exponential distribution of charges through the downward leader. The voltage condition used by Rizk is used to investigate the inception of the upward lightning leader. Different air conditions (relative air density and air humidity) are considered for more practical simulation. The influences of lightning parameters and lightning rod height on the shielding angle are studied. The results shows that, lightning leader parameters, lightning rod height and ground slope have a series effects on the shielding angle of the lightning rod. Based on the results, recommendations are supposed to decrease the lightning stroke to the lightning rod.
{"title":"Investigation of Lightning Rod Shielding Angle","authors":"M. Nayel","doi":"10.1109/IAS.2010.5616747","DOIUrl":"https://doi.org/10.1109/IAS.2010.5616747","url":null,"abstract":"This paper studies those parameters affecting the shielding angle of the lightning rod (Franklin Rod) above very tall buildings. It is recommended that the shielding angle of the lightning rod is about 45o ~ 60o. The downward lightning leader is modeled by using discrete line charge to consider the exponential distribution of charges through the downward leader. The voltage condition used by Rizk is used to investigate the inception of the upward lightning leader. Different air conditions (relative air density and air humidity) are considered for more practical simulation. The influences of lightning parameters and lightning rod height on the shielding angle are studied. The results shows that, lightning leader parameters, lightning rod height and ground slope have a series effects on the shielding angle of the lightning rod. Based on the results, recommendations are supposed to decrease the lightning stroke to the lightning rod.","PeriodicalId":317643,"journal":{"name":"2010 IEEE Industry Applications Society Annual Meeting","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122434581","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 : 2010-11-01DOI: 10.1109/IAS.2010.5616038
H. Fujishima, Y. Yoshioka, T. Kuroki, A. Tanaka, K. Otsuka, M. Okubo
A pilot-scale low emission boiler plant which consists of a multi-fuel boiler and a plasma-chemical hybrid NOx removal system was investigated. This plant can achieve carbon neutrality because the multi-fuel boiler uses waste vegetable oil as one of fuels. The plasma-chemical hybrid NOx removal system has two processes; one is NO oxidation by ozone produced from plasma ozonizers, and the other is NO2 removal using a Na2SO3 chemical scrubber. The operation tests of the plant were carried out for mixed oils (mixture of heavy oil and waste vegetable oil). Stable combustion was achieved for the mixed oil (20%~50% vegetable oil). The flue gas properties, such as O2, CO2 and NOx in firing mixed oils, were nearly the same as those in firing heavy oil when the flue gas flow rate was 1000 Nm3/h on average. NOx concentrations at boiler outlet were 90~95 ppm. Furthermore, it is confirmed that during a 300 min continuous operation in firing 20% mixed oil NOx removal efficiency was attained more than 90%, equivalent to less than 10 ppm at scrubber outlet when the flue gas flow rate was 870 Nm3/h. In addition, the effect of replacing heavy oil by waste vegetable oil on CO2 reduction was estimated.
{"title":"Operation Test of Pilot-Scale Low-Emission Multi-Fuel Boiler with Plasma-Chemical Hybrid NOx Reduction System","authors":"H. Fujishima, Y. Yoshioka, T. Kuroki, A. Tanaka, K. Otsuka, M. Okubo","doi":"10.1109/IAS.2010.5616038","DOIUrl":"https://doi.org/10.1109/IAS.2010.5616038","url":null,"abstract":"A pilot-scale low emission boiler plant which consists of a multi-fuel boiler and a plasma-chemical hybrid NOx removal system was investigated. This plant can achieve carbon neutrality because the multi-fuel boiler uses waste vegetable oil as one of fuels. The plasma-chemical hybrid NOx removal system has two processes; one is NO oxidation by ozone produced from plasma ozonizers, and the other is NO2 removal using a Na2SO3 chemical scrubber. The operation tests of the plant were carried out for mixed oils (mixture of heavy oil and waste vegetable oil). Stable combustion was achieved for the mixed oil (20%~50% vegetable oil). The flue gas properties, such as O2, CO2 and NOx in firing mixed oils, were nearly the same as those in firing heavy oil when the flue gas flow rate was 1000 Nm3/h on average. NOx concentrations at boiler outlet were 90~95 ppm. Furthermore, it is confirmed that during a 300 min continuous operation in firing 20% mixed oil NOx removal efficiency was attained more than 90%, equivalent to less than 10 ppm at scrubber outlet when the flue gas flow rate was 870 Nm3/h. In addition, the effect of replacing heavy oil by waste vegetable oil on CO2 reduction was estimated.","PeriodicalId":317643,"journal":{"name":"2010 IEEE Industry Applications Society Annual Meeting","volume":"11628 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114165453","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 : 2010-11-01DOI: 10.1109/IAS.2010.5615500
Cheng-Tsung Liu, Li-Yang Liu, Sheng-Yang Lin
To provide detailed information of electromagnetic steels to potential customers, comprehensive test results that can properly indicate the iron losses of those laminated products at different operational specifications are desired from the steel manufacturers. However, with limited experimental measurements, the available datasheets can only cover some typical information that were determined from common Epstein Frame tests, and additional data regarding possible iron losses beyond the conducted measurement setups will thus be estimated by numerical approximations. Accuracies of applying these data for related machine performance evaluations at those operational conditions are always uncertain, and more convincing datasheet that can adequately characterize the electromagnetic steel properties is certainly expected. Based on Preisach model and measured information, a systematic scheme that can establish the generalized hysteresis characteristics of the electromagnetic steel will be proposed. Supported by experimental measurements and devised analytical models, confident and comprehensive iron losses of those energy conversion mechanisms constructed by laminated steels can be adequately evaluated at all feasible operational specifications.
{"title":"A Systematic Iron Loss Evaluating Scheme for Electromagnetic Steel Products","authors":"Cheng-Tsung Liu, Li-Yang Liu, Sheng-Yang Lin","doi":"10.1109/IAS.2010.5615500","DOIUrl":"https://doi.org/10.1109/IAS.2010.5615500","url":null,"abstract":"To provide detailed information of electromagnetic steels to potential customers, comprehensive test results that can properly indicate the iron losses of those laminated products at different operational specifications are desired from the steel manufacturers. However, with limited experimental measurements, the available datasheets can only cover some typical information that were determined from common Epstein Frame tests, and additional data regarding possible iron losses beyond the conducted measurement setups will thus be estimated by numerical approximations. Accuracies of applying these data for related machine performance evaluations at those operational conditions are always uncertain, and more convincing datasheet that can adequately characterize the electromagnetic steel properties is certainly expected. Based on Preisach model and measured information, a systematic scheme that can establish the generalized hysteresis characteristics of the electromagnetic steel will be proposed. Supported by experimental measurements and devised analytical models, confident and comprehensive iron losses of those energy conversion mechanisms constructed by laminated steels can be adequately evaluated at all feasible operational specifications.","PeriodicalId":317643,"journal":{"name":"2010 IEEE Industry Applications Society Annual Meeting","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114713127","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 : 2010-11-01DOI: 10.1109/IAS.2010.5615257
Rajesh Sharma, H. Ishihara, A. Biris, M. Mazumder
A number of metal oxide semiconductors based photoelectrochemical processes have been utilized in environmental and energy related application. With increased urgency in the search for alternative sources of energy, photoelectrolysis of water for generation of hydrogen using solar radiation has attracted great attention. Several metal oxide semiconductors have been considered as promising materials for photoelectrochemical generation of hydrogen. They are photostable, chemically inert, and cost effective. However, most stable semiconducting electrodes have large band gaps and hence low efficiency for photo-conversion for the entire spectrum of solar radiation. Reduction of band gap by doping the bulk of the semiconductor has not been found successful since such a process introduces charge carrier traps and compromises electron conduction and material durability. Vertical and ordered nanotubular titania (TiO2) arrays were synthesized by electrochemical anodization of Ti thin foils. Plasma surface doping of TiO2 nanotubular photoanodes resulted in a significantly enhanced photocurrent density.
{"title":"Development of Surface Engineered Nanostructured Photoanodes for Enhanced Photo Electrochemical Processes","authors":"Rajesh Sharma, H. Ishihara, A. Biris, M. Mazumder","doi":"10.1109/IAS.2010.5615257","DOIUrl":"https://doi.org/10.1109/IAS.2010.5615257","url":null,"abstract":"A number of metal oxide semiconductors based photoelectrochemical processes have been utilized in environmental and energy related application. With increased urgency in the search for alternative sources of energy, photoelectrolysis of water for generation of hydrogen using solar radiation has attracted great attention. Several metal oxide semiconductors have been considered as promising materials for photoelectrochemical generation of hydrogen. They are photostable, chemically inert, and cost effective. However, most stable semiconducting electrodes have large band gaps and hence low efficiency for photo-conversion for the entire spectrum of solar radiation. Reduction of band gap by doping the bulk of the semiconductor has not been found successful since such a process introduces charge carrier traps and compromises electron conduction and material durability. Vertical and ordered nanotubular titania (TiO2) arrays were synthesized by electrochemical anodization of Ti thin foils. Plasma surface doping of TiO2 nanotubular photoanodes resulted in a significantly enhanced photocurrent density.","PeriodicalId":317643,"journal":{"name":"2010 IEEE Industry Applications Society Annual Meeting","volume":"207 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115185060","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 : 2010-11-01DOI: 10.1109/IAS.2010.5616840
K. Adamiak, J. M. Floryan
Distortion of a free droplet in a uniform electric field is studied numerically using the Boundary Element Method. It is assumed that the droplet is made of an ideally conducting liquid. There exists a critical magnitude of the electric field intensity. The droplet oscillates for weaker electric fields and elongates until a thin jet emanating from the droplet tip is formed for stronger electric fields. Numerical predictions agree reasonably well with the available experimental data.
{"title":"Dynamics of Water Droplet Distortion and Break-Up in a Uniform Electric Field","authors":"K. Adamiak, J. M. Floryan","doi":"10.1109/IAS.2010.5616840","DOIUrl":"https://doi.org/10.1109/IAS.2010.5616840","url":null,"abstract":"Distortion of a free droplet in a uniform electric field is studied numerically using the Boundary Element Method. It is assumed that the droplet is made of an ideally conducting liquid. There exists a critical magnitude of the electric field intensity. The droplet oscillates for weaker electric fields and elongates until a thin jet emanating from the droplet tip is formed for stronger electric fields. Numerical predictions agree reasonably well with the available experimental data.","PeriodicalId":317643,"journal":{"name":"2010 IEEE Industry Applications Society Annual Meeting","volume":"64 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123469206","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 : 2010-11-01DOI: 10.1109/IAS.2010.5615297
K. P. Bhat, K. Oh, D. Hopkins
Abstract - This paper addresses protection of oil insulated power equipment, e.g. transformers, using a MEMS sensor system to augment or replace existing protection techniques. Traditional technologies used for protection and analysis involve pressure and temperature sensing, gas chromatography and/or a Buchholz relay. A MEMS sensor is described to augment or replace such sensors. The proposed device is immersed within the insulating fluid, e.g. oil, and primarily consists of multiple micro scale turbines centrally shafted to a MEMS generator. The device utilizes relative differences in velocity, pressure and flow rate, of gas emanating from stressed or degrading insulation. A differential electrical output is produced which can be RF or photon coupled to a user interface.
{"title":"A MEMS Sensor for Gas Detection in High Voltage Oil Filled Equipment","authors":"K. P. Bhat, K. Oh, D. Hopkins","doi":"10.1109/IAS.2010.5615297","DOIUrl":"https://doi.org/10.1109/IAS.2010.5615297","url":null,"abstract":"Abstract - This paper addresses protection of oil insulated power equipment, e.g. transformers, using a MEMS sensor system to augment or replace existing protection techniques. Traditional technologies used for protection and analysis involve pressure and temperature sensing, gas chromatography and/or a Buchholz relay. A MEMS sensor is described to augment or replace such sensors. The proposed device is immersed within the insulating fluid, e.g. oil, and primarily consists of multiple micro scale turbines centrally shafted to a MEMS generator. The device utilizes relative differences in velocity, pressure and flow rate, of gas emanating from stressed or degrading insulation. A differential electrical output is produced which can be RF or photon coupled to a user interface.","PeriodicalId":317643,"journal":{"name":"2010 IEEE Industry Applications Society Annual Meeting","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131061501","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 : 2010-11-01DOI: 10.1109/IAS.2010.5615424
T. Kuroki, K. Hirai, S. Matsuoka, Jong Youl Kim, M. Okubo
The bench-scale test of toluene decomposition is carried out using adsorption and surface discharge with gas circulation. The liquid toluene is vaporized in the circulation line, and the toluene gas is adsorbed by the adsorbent. The hydrophobic zeolite pellet is used as an adsorbent. After the toluene adsorption, ozone generated by surface discharge is supplied to the adsorbent and adsorbed toluene is decomposed. Because the gas is circulated during toluene decomposition, ozone is used to decompose toluene effectively without waste. As a result, adsorbed toluene is converted to COx efficiently using surface discharge with gas circulation; 88% and 43% of conversion ratio of toluene to COx are achieved when 1 and 6 ml of toluene are decomposed for 90 and 150 min, respectively. In addition, the more than 89% of CO2 selectivity is obtained when 1 and 6 ml of toluene are decomposed. The conversion rate of toluene to COx and the energy efficiency of toluene conversion to COx increase with the amount of adsorbed toluene.
{"title":"Bench-Scale Test of Toluene Decomposition Using Adsorption and Surface Discharge with Gas Circulation","authors":"T. Kuroki, K. Hirai, S. Matsuoka, Jong Youl Kim, M. Okubo","doi":"10.1109/IAS.2010.5615424","DOIUrl":"https://doi.org/10.1109/IAS.2010.5615424","url":null,"abstract":"The bench-scale test of toluene decomposition is carried out using adsorption and surface discharge with gas circulation. The liquid toluene is vaporized in the circulation line, and the toluene gas is adsorbed by the adsorbent. The hydrophobic zeolite pellet is used as an adsorbent. After the toluene adsorption, ozone generated by surface discharge is supplied to the adsorbent and adsorbed toluene is decomposed. Because the gas is circulated during toluene decomposition, ozone is used to decompose toluene effectively without waste. As a result, adsorbed toluene is converted to COx efficiently using surface discharge with gas circulation; 88% and 43% of conversion ratio of toluene to COx are achieved when 1 and 6 ml of toluene are decomposed for 90 and 150 min, respectively. In addition, the more than 89% of CO2 selectivity is obtained when 1 and 6 ml of toluene are decomposed. The conversion rate of toluene to COx and the energy efficiency of toluene conversion to COx increase with the amount of adsorbed toluene.","PeriodicalId":317643,"journal":{"name":"2010 IEEE Industry Applications Society Annual Meeting","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129635370","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 : 2010-11-01DOI: 10.1109/IAS.2010.5615666
Meurig W. Williams
Experimental results of the triboelectric charging of insulators have variously been interpreted in terms of either electron or ion exchange, but the field is fraught with contradictions and it remains one of the least understood areas of solid state physics. We approached this contentious issue from the point of view of charge penetration depth (CPD) into the surfaces of insulators. Hitherto, it appears that the questions of charging mechanisms of insulators and charge penetration depth into insulators have been treated separately. We show how these are related in the form a coherent model for metal-insulator and insulator-insulator charging. Using a polymer chemistry approach, combined with XPS surface analysis, we designed a series of polymer films such that their surface compositions were different from those of the bulk. We found that charging against these films fell into two distinct patterns depending on whether the charging was with metals or other insulators. Charging with insulators related to the topmost surface layers of the films, but charging with metals related to the deeper levels of the bulk compositions, clearly indicating that different mechanisms MUST be involved. We propose that charging against insulators involves ion adsorption to the topmost atomic layers of the films; and charging against metals involves electron tunneling deeper into the bulk of the films. Others have proposed electron and ion exchange mechanisms using different systems for each but, as far as we know, this work is the first to invoke both electron AND ion exchange mechanisms for the same insulating films; and it is for this reason we believe that the approach described here, together with advanced surface analysis techniques, provides the scope and flexibility for precise quantification of charge penetration depths, which could lead to totally definitive evidence for electron versus ion involvement. Integrating our work with that of others has resulted in modification of the above model such that both electron and ion exchange mechanisms exist simultaneously for metal-insulator charging. A specific experimental approach is identified to verify this updated model. Part of this work was conducted at Xerox Corporation and presented at the 1975 IEEE meeting in Atlanta, GA (1). Here it is expanded and interpreted in the light of recent developments.
{"title":"Triboelectric Charging of Insulators - Evidence for Electrons versus Ions","authors":"Meurig W. Williams","doi":"10.1109/IAS.2010.5615666","DOIUrl":"https://doi.org/10.1109/IAS.2010.5615666","url":null,"abstract":"Experimental results of the triboelectric charging of insulators have variously been interpreted in terms of either electron or ion exchange, but the field is fraught with contradictions and it remains one of the least understood areas of solid state physics. We approached this contentious issue from the point of view of charge penetration depth (CPD) into the surfaces of insulators. Hitherto, it appears that the questions of charging mechanisms of insulators and charge penetration depth into insulators have been treated separately. We show how these are related in the form a coherent model for metal-insulator and insulator-insulator charging. Using a polymer chemistry approach, combined with XPS surface analysis, we designed a series of polymer films such that their surface compositions were different from those of the bulk. We found that charging against these films fell into two distinct patterns depending on whether the charging was with metals or other insulators. Charging with insulators related to the topmost surface layers of the films, but charging with metals related to the deeper levels of the bulk compositions, clearly indicating that different mechanisms MUST be involved. We propose that charging against insulators involves ion adsorption to the topmost atomic layers of the films; and charging against metals involves electron tunneling deeper into the bulk of the films. Others have proposed electron and ion exchange mechanisms using different systems for each but, as far as we know, this work is the first to invoke both electron AND ion exchange mechanisms for the same insulating films; and it is for this reason we believe that the approach described here, together with advanced surface analysis techniques, provides the scope and flexibility for precise quantification of charge penetration depths, which could lead to totally definitive evidence for electron versus ion involvement. Integrating our work with that of others has resulted in modification of the above model such that both electron and ion exchange mechanisms exist simultaneously for metal-insulator charging. A specific experimental approach is identified to verify this updated model. Part of this work was conducted at Xerox Corporation and presented at the 1975 IEEE meeting in Atlanta, GA (1). Here it is expanded and interpreted in the light of recent developments.","PeriodicalId":317643,"journal":{"name":"2010 IEEE Industry Applications Society Annual Meeting","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128868917","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 : 2010-11-01DOI: 10.1109/IAS.2010.5616035
J. Pontt, R. Vargas
For grinding aplications cycloconverter-fed gearless mill drives are being applied with increasing powers and new risks emerge with the systems scaling-up. Traditional parasitic second order effects may be not neglected, like thermal expansions, electromagnetic effects and EMC emissions. In this frame, harmonics and partial discharges of windings in medium voltage converter-fed machines build additional leakage current background that masks eventual phase insulation failures or produce nuissance trips in the protective system. Despite these perturbations, for reliable operation, the electrical protection system must detect properly a phase-to-ground fault of the motor in the 100% length of stator winding with the trade-off between sensititvity ad insensitivity. This work presents a study and discussion based on modeling and simulation for assessing the limitations and range of application of a 100% earth fault protection configuration, considering the operation of this protection acting also as earth leakage protection.
{"title":"Analysis of a Stator Earth Fault Protection System of a Medium Voltage Converter-Fed Synchronous Motor","authors":"J. Pontt, R. Vargas","doi":"10.1109/IAS.2010.5616035","DOIUrl":"https://doi.org/10.1109/IAS.2010.5616035","url":null,"abstract":"For grinding aplications cycloconverter-fed gearless mill drives are being applied with increasing powers and new risks emerge with the systems scaling-up. Traditional parasitic second order effects may be not neglected, like thermal expansions, electromagnetic effects and EMC emissions. In this frame, harmonics and partial discharges of windings in medium voltage converter-fed machines build additional leakage current background that masks eventual phase insulation failures or produce nuissance trips in the protective system. Despite these perturbations, for reliable operation, the electrical protection system must detect properly a phase-to-ground fault of the motor in the 100% length of stator winding with the trade-off between sensititvity ad insensitivity. This work presents a study and discussion based on modeling and simulation for assessing the limitations and range of application of a 100% earth fault protection configuration, considering the operation of this protection acting also as earth leakage protection.","PeriodicalId":317643,"journal":{"name":"2010 IEEE Industry Applications Society Annual Meeting","volume":"73 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127321218","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 : 2010-11-01DOI: 10.1109/IAS.2010.5616771
L. Kojovic, T. R. Day, D. Sharma
This companion paper to that presented at the 2009 IEEE IAS Annual Meeting describes new differential protection solutions for electric arc furnace (EAF) power systems that use Rogowski Coils as current sensors. These novel solutions provide multiple protection zones, covering the entire EAF electric supply system. The protection philosophy includes multiple differential zones of protection such as cables serving the EAF vault, series reactors, EAF transformers (including all power apparatus in the protection zones), and busbars.
{"title":"Innovative Differential Protection of EAF Electrical Systems Using Low Energy Current Sensors","authors":"L. Kojovic, T. R. Day, D. Sharma","doi":"10.1109/IAS.2010.5616771","DOIUrl":"https://doi.org/10.1109/IAS.2010.5616771","url":null,"abstract":"This companion paper to that presented at the 2009 IEEE IAS Annual Meeting describes new differential protection solutions for electric arc furnace (EAF) power systems that use Rogowski Coils as current sensors. These novel solutions provide multiple protection zones, covering the entire EAF electric supply system. The protection philosophy includes multiple differential zones of protection such as cables serving the EAF vault, series reactors, EAF transformers (including all power apparatus in the protection zones), and busbars.","PeriodicalId":317643,"journal":{"name":"2010 IEEE Industry Applications Society Annual Meeting","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121672581","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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