S. Kanazawa, T. Ohkubo, T. Adachi, M. Inokuchi, A. Shibuya
Flow field around silicon wafer in a clean room is discussed on the basis of experimental results obtained using smoke visualization and the Schlieren method. Several examples of flow pattern are presented to show the influence of aerodynamic conditions on particle transportation. The characteristic flow phenomena around stagnation point flow and vortices generated behind the wafer are made clear from the observed streamlines by the Schlieren method. The observed flow field for the vertical airflow over a horizontal wafer is compared with the simulation result given in Liu et al. (1987). The dependence of airflow on wafer surface temperature is also discussed. Results show that the fluid flow for a normal condition is an axisymmetric flow, while, for a wafer heated condition, the behavior of fluid flow is changed extremely and the effect of thermal convection is dominant compared with the main downward air flow.<>
基于烟雾可视化和纹影法的实验结果，讨论了洁净室中硅片周围的流场。文中列举了几个流型的例子来说明气动条件对颗粒输运的影响。用纹影法从观察到的流线上清晰地显示了晶圆周围的滞止点流动和晶圆后产生的涡的特征流动现象。将观测到的水平薄片上垂直气流的流场与Liu et al.(1987)给出的模拟结果进行了比较。文中还讨论了气流对晶圆表面温度的影响。结果表明:在正常条件下，流体流动为轴对称流动，而在加热条件下，流体的流动行为发生了极大的变化，与主要的向下气流相比，热对流的作用占主导地位
{"title":"Flow visualization of a particle deposition on silicon wafers in clean rooms","authors":"S. Kanazawa, T. Ohkubo, T. Adachi, M. Inokuchi, A. Shibuya","doi":"10.1109/IAS.1991.178239","DOIUrl":"https://doi.org/10.1109/IAS.1991.178239","url":null,"abstract":"Flow field around silicon wafer in a clean room is discussed on the basis of experimental results obtained using smoke visualization and the Schlieren method. Several examples of flow pattern are presented to show the influence of aerodynamic conditions on particle transportation. The characteristic flow phenomena around stagnation point flow and vortices generated behind the wafer are made clear from the observed streamlines by the Schlieren method. The observed flow field for the vertical airflow over a horizontal wafer is compared with the simulation result given in Liu et al. (1987). The dependence of airflow on wafer surface temperature is also discussed. Results show that the fluid flow for a normal condition is an axisymmetric flow, while, for a wafer heated condition, the behavior of fluid flow is changed extremely and the effect of thermal convection is dominant compared with the main downward air flow.<<ETX>>","PeriodicalId":294244,"journal":{"name":"Conference Record of the 1991 IEEE Industry Applications Society Annual Meeting","volume":"71 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128713508","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}
A procedure for designing variable-reluctance motor (VRM) drives for low torque-ripple applications. The procedure is comprehensive because it begins with the fundamental selection of pole numbers and geometry, and proceeds to final design. It provides a complete, clear and concise path to a successful design for a low torque-ripple drive. There are two important contributions of the work presented. First, the design procedure explicates the issues involved in designing VRMs for torque-ripple sensitive applications. Second, results of the motor design are amenable to simple control methods which offer acceptable performance in many applications. In the procedure outlined the VRM geometry, inverter voltages are tailored to minimize torque ripple.<>
{"title":"A comprehensive design procedure for low torque-ripple variable-reluctance motor drives","authors":"D.P. Tormey, D. Torrey","doi":"10.1109/IAS.1991.178162","DOIUrl":"https://doi.org/10.1109/IAS.1991.178162","url":null,"abstract":"A procedure for designing variable-reluctance motor (VRM) drives for low torque-ripple applications. The procedure is comprehensive because it begins with the fundamental selection of pole numbers and geometry, and proceeds to final design. It provides a complete, clear and concise path to a successful design for a low torque-ripple drive. There are two important contributions of the work presented. First, the design procedure explicates the issues involved in designing VRMs for torque-ripple sensitive applications. Second, results of the motor design are amenable to simple control methods which offer acceptable performance in many applications. In the procedure outlined the VRM geometry, inverter voltages are tailored to minimize torque ripple.<<ETX>>","PeriodicalId":294244,"journal":{"name":"Conference Record of the 1991 IEEE Industry Applications Society Annual Meeting","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132420560","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}
Some principles of machine learning and some links with knowledge base system are described. A domain-independent inductive learning system (ILS) has been developed and implemented. ILS can be attached to any expert system, and will work as a knowledge acquisition module for the expert system. This gives the expert system the ability to update and expand its knowledge base according to the circumstances. ILS is a logic-based, data-driven learning system, focusing on the problem of learning structural descriptions. ILS is tailored to design electrical system components. In the present work, ILS is used for specifying the major components of an electrical substation. The learning system will learn design rules and concepts from positive and negative examples in the form of existing substations. This system will take examples and generate rules and concepts for specifying the major components of an electric substation.<>
{"title":"Learning design rules and concepts for examples-a case study to design an electric power substation design","authors":"Y.B. Mahdy, E. Stanek, M. Abdel-Salam, M. Zaki","doi":"10.1109/IAS.1991.178016","DOIUrl":"https://doi.org/10.1109/IAS.1991.178016","url":null,"abstract":"Some principles of machine learning and some links with knowledge base system are described. A domain-independent inductive learning system (ILS) has been developed and implemented. ILS can be attached to any expert system, and will work as a knowledge acquisition module for the expert system. This gives the expert system the ability to update and expand its knowledge base according to the circumstances. ILS is a logic-based, data-driven learning system, focusing on the problem of learning structural descriptions. ILS is tailored to design electrical system components. In the present work, ILS is used for specifying the major components of an electrical substation. The learning system will learn design rules and concepts from positive and negative examples in the form of existing substations. This system will take examples and generate rules and concepts for specifying the major components of an electric substation.<<ETX>>","PeriodicalId":294244,"journal":{"name":"Conference Record of the 1991 IEEE Industry Applications Society Annual Meeting","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132328680","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The authors present theoretical considerations and laboratory experimental results of an electrostatic system designed to suppress tank emissions at their source, i.e. at the surface of the tanks. It is found that tank emissions in the form of a mist are substantially reduced by being repelled back into the tank. The reductions measured in terms of copper, nickel, cobalt, iron, sulphuric acid, and arsenic were all on the order of 50%, except for the iron and sulphuric acid data which show approximately a 20% reduction for the sulphuric acid, 60% for the iron when spraying charged water.<>
{"title":"Suppression of emissions from large electrolytic tanks by means of fine, charged water droplets (phase I)","authors":"I. Inculet, J.F. Eggleston, G. Castle, K. Bech","doi":"10.1109/IAS.1991.178323","DOIUrl":"https://doi.org/10.1109/IAS.1991.178323","url":null,"abstract":"The authors present theoretical considerations and laboratory experimental results of an electrostatic system designed to suppress tank emissions at their source, i.e. at the surface of the tanks. It is found that tank emissions in the form of a mist are substantially reduced by being repelled back into the tank. The reductions measured in terms of copper, nickel, cobalt, iron, sulphuric acid, and arsenic were all on the order of 50%, except for the iron and sulphuric acid data which show approximately a 20% reduction for the sulphuric acid, 60% for the iron when spraying charged water.<<ETX>>","PeriodicalId":294244,"journal":{"name":"Conference Record of the 1991 IEEE Industry Applications Society Annual Meeting","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130900880","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}
Fluorescent lamps can lose 10-20% in light output and 5-10% in efficacy enclosed and thermally constricted multilamp fixtures. The authors present two thermal bridge concepts that increase the performance of a T12 lamp/fixture under typical operating conditions. The first bridge utilizes the conformable and convective properties of a liquid heat sink. The second bridge utilizes the semiridged and conductive properties of aluminum and copper. The results indicate that a potential 10-20% increase in light output can be maintained by applying a thermal bridge system to cool a small section of the lamp's surface. This corresponds to a recovery of 300-600 lumens per lamp. Additional advantages of using the thermal bridge systems are small size, minimal optical losses, no dust factor that is associated with vented fixture designs, and potentially low integration cost.<>
{"title":"The application of a thermal bridge to increase light output of a T12 fluorescent fixture system","authors":"M. Packer, M. Siminovitch","doi":"10.1109/IAS.1991.178121","DOIUrl":"https://doi.org/10.1109/IAS.1991.178121","url":null,"abstract":"Fluorescent lamps can lose 10-20% in light output and 5-10% in efficacy enclosed and thermally constricted multilamp fixtures. The authors present two thermal bridge concepts that increase the performance of a T12 lamp/fixture under typical operating conditions. The first bridge utilizes the conformable and convective properties of a liquid heat sink. The second bridge utilizes the semiridged and conductive properties of aluminum and copper. The results indicate that a potential 10-20% increase in light output can be maintained by applying a thermal bridge system to cool a small section of the lamp's surface. This corresponds to a recovery of 300-600 lumens per lamp. Additional advantages of using the thermal bridge systems are small size, minimal optical losses, no dust factor that is associated with vented fixture designs, and potentially low integration cost.<<ETX>>","PeriodicalId":294244,"journal":{"name":"Conference Record of the 1991 IEEE Industry Applications Society Annual Meeting","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131316886","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}
A three-phase quasi-resonant DC link inverter (QRI), which adopts the resonant circuit with one additional switch, is proposed. The circuit states for given switching and load current states in the inverter are analyzed, and then an equivalent circuit seen from the inverter input side is derived. By using this equivalent circuit the QRI is analyzed, and two control techniques, which are the initial current control technique of resonant inductor and the initial voltage control technique of resonant capacitor, are presented in order to obtain the desirable oscillation of resonant link irrespective of inverter operation. The operating characteristics of QRI are verified through both simulations and experiments.<>
{"title":"A novel three-phase quasi-resonant DC link inverter","authors":"J.-W. Lee, S. Sul, M. Park","doi":"10.1109/IAS.1991.178331","DOIUrl":"https://doi.org/10.1109/IAS.1991.178331","url":null,"abstract":"A three-phase quasi-resonant DC link inverter (QRI), which adopts the resonant circuit with one additional switch, is proposed. The circuit states for given switching and load current states in the inverter are analyzed, and then an equivalent circuit seen from the inverter input side is derived. By using this equivalent circuit the QRI is analyzed, and two control techniques, which are the initial current control technique of resonant inductor and the initial voltage control technique of resonant capacitor, are presented in order to obtain the desirable oscillation of resonant link irrespective of inverter operation. The operating characteristics of QRI are verified through both simulations and experiments.<<ETX>>","PeriodicalId":294244,"journal":{"name":"Conference Record of the 1991 IEEE Industry Applications Society Annual Meeting","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128769259","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}
Nondestructive evaluations of IGBTs (insulated-gate bipolar transistors) and MCTs (MOS-controller thyristors) are discussed and their corresponding RBSOAs established. Test results are presented for a variety of commercial devices at different temperatures. It was observed that, compared to BJTs (bipolar junction transistors), IGBTs and MCTs exhibit very different turn-off breakdown characteristics. Avalanche breakdown of the parasitic transistor accounts for the loss of dynamic voltage blocking capability of both IGBTs and MCTs.<>
{"title":"Nondestructive RBSOA characterization of IGBTs and MCTs","authors":"D. Chen, F. Lee, G. Carpenter","doi":"10.1109/IAS.1991.178066","DOIUrl":"https://doi.org/10.1109/IAS.1991.178066","url":null,"abstract":"Nondestructive evaluations of IGBTs (insulated-gate bipolar transistors) and MCTs (MOS-controller thyristors) are discussed and their corresponding RBSOAs established. Test results are presented for a variety of commercial devices at different temperatures. It was observed that, compared to BJTs (bipolar junction transistors), IGBTs and MCTs exhibit very different turn-off breakdown characteristics. Avalanche breakdown of the parasitic transistor accounts for the loss of dynamic voltage blocking capability of both IGBTs and MCTs.<<ETX>>","PeriodicalId":294244,"journal":{"name":"Conference Record of the 1991 IEEE Industry Applications Society Annual Meeting","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126794386","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}
A zero voltage switched active network which can be used in conjunction with single-phase or three-phase AC to DC diode rectifiers is presented. It is shown that application of the proposed switching network in a three-phase AC to DC boost converter yields zero switching losses while maintaining a unity input power factor. Active network capacitor, C/sub s/, diodes D/sub 7/ and D/sub 8/ maintain a zero voltage during turn-off of Q/sub 1/ and Q/sub 2/. Capacitor discharges through the boost inductors of the circuit, thus limiting the rate of rise of current during turn-on. Moreover, the advantage of the proposed active network is that it can maintain a zero voltage switching over the entire range of the duty cycle of the operation. Consequently, boost stage can be used directly to control the DC bus voltage by varying the duty cycle at constant switching frequency.<>
{"title":"Active input current waveshaping method for three-phase diode rectifiers with zero switching losses","authors":"A. Prasad, P. Ziogas","doi":"10.1109/IAS.1991.178349","DOIUrl":"https://doi.org/10.1109/IAS.1991.178349","url":null,"abstract":"A zero voltage switched active network which can be used in conjunction with single-phase or three-phase AC to DC diode rectifiers is presented. It is shown that application of the proposed switching network in a three-phase AC to DC boost converter yields zero switching losses while maintaining a unity input power factor. Active network capacitor, C/sub s/, diodes D/sub 7/ and D/sub 8/ maintain a zero voltage during turn-off of Q/sub 1/ and Q/sub 2/. Capacitor discharges through the boost inductors of the circuit, thus limiting the rate of rise of current during turn-on. Moreover, the advantage of the proposed active network is that it can maintain a zero voltage switching over the entire range of the duty cycle of the operation. Consequently, boost stage can be used directly to control the DC bus voltage by varying the duty cycle at constant switching frequency.<<ETX>>","PeriodicalId":294244,"journal":{"name":"Conference Record of the 1991 IEEE Industry Applications Society Annual Meeting","volume":"84 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126251488","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}
A simple method is presented to find a circuit model for a given ESD (electrostatic discharge) waveform. The proposed technique is considerably simpler than previously described methods. A measured ESD current waveform is expressed as a linear combination of a set of basis functions. Each basis function is modeled by a first-order or a second-order RLC circuit. Many ESD waveforms can be adequately modeled with three or less basis functions.<>
{"title":"Simplified circuit modeling of ESD waveforms","authors":"Y. Chang, M. Rudko, C. Wu","doi":"10.1109/IAS.1991.178232","DOIUrl":"https://doi.org/10.1109/IAS.1991.178232","url":null,"abstract":"A simple method is presented to find a circuit model for a given ESD (electrostatic discharge) waveform. The proposed technique is considerably simpler than previously described methods. A measured ESD current waveform is expressed as a linear combination of a set of basis functions. Each basis function is modeled by a first-order or a second-order RLC circuit. Many ESD waveforms can be adequately modeled with three or less basis functions.<<ETX>>","PeriodicalId":294244,"journal":{"name":"Conference Record of the 1991 IEEE Industry Applications Society Annual Meeting","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121304067","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The minimization of the torque ripple in permanent magnets synchronous motors is achieved either by a special motor design or by an adequate control of the driver. In both cases, the driver or the motor choice is made so that both elements are complementary. The presented approach yields either appropriate current shapes to drive a given motor without torque ripple or appropriate back EMF shapes for a given current or voltage supply. The torque components due to the interaction between the magnets and the stator slots are taken into account.<>
{"title":"Permanent magnets synchronous motors: a general approach for cogging torque suppression","authors":"E. Favre, L. Cardoletti, M. Jufer","doi":"10.1109/IAS.1991.178156","DOIUrl":"https://doi.org/10.1109/IAS.1991.178156","url":null,"abstract":"The minimization of the torque ripple in permanent magnets synchronous motors is achieved either by a special motor design or by an adequate control of the driver. In both cases, the driver or the motor choice is made so that both elements are complementary. The presented approach yields either appropriate current shapes to drive a given motor without torque ripple or appropriate back EMF shapes for a given current or voltage supply. The torque components due to the interaction between the magnets and the stator slots are taken into account.<<ETX>>","PeriodicalId":294244,"journal":{"name":"Conference Record of the 1991 IEEE Industry Applications Society Annual Meeting","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115251946","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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