The authors present a fast and approximate method for calculation of frequency and duration of voltage drops in plants which have a large number of intermittent loads such as welders and robots. The intermittent nature of welder and robot loads is approximated by the Markov model for computing the frequency and duration. A novel approach combining the Markov model with voltage drop calculations by aggregating states is presented to compute the magnitude, probability, frequency, and duration of voltage drops. In addition, this method is used to analyze flicker problems due to intermittent loads and evaluate the effectiveness of mitigation methods.<>
{"title":"Frequency and duration of voltage drop in plants with intermittent loads","authors":"F. S. Prabhakara, J. J. Miller, W. E. Kazibwe","doi":"10.1109/IAS.1991.178072","DOIUrl":"https://doi.org/10.1109/IAS.1991.178072","url":null,"abstract":"The authors present a fast and approximate method for calculation of frequency and duration of voltage drops in plants which have a large number of intermittent loads such as welders and robots. The intermittent nature of welder and robot loads is approximated by the Markov model for computing the frequency and duration. A novel approach combining the Markov model with voltage drop calculations by aggregating states is presented to compute the magnitude, probability, frequency, and duration of voltage drops. In addition, this method is used to analyze flicker problems due to intermittent loads and evaluate the effectiveness of mitigation methods.<<ETX>>","PeriodicalId":294244,"journal":{"name":"Conference Record of the 1991 IEEE Industry Applications Society Annual Meeting","volume":"129 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":"132511035","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 characteristics and effects of nonlinear loads in the commercial office environment are discussed. The interaction of distorted currents drawn by these loads with the power system are described. An approximate approach for evaluating potential problems within a given facility is discussed, which, while not rigorous, can be used as a screening tool by building designers and engineers to make assessments of the potential for harmonic problems. Effects of high relative levels of harmonic current generation in commercial buildings include harmonic voltage distortion, transformer and motor overheating, and neutral conductor overloading. Reasonable estimates of the impacts of nonlinear loads can be made from generalized harmonic current source characteristics of three basic nonlinear types. Interactions with the electric power system can be predicted with simplified representations of the building electrical system.<>
{"title":"Assessing the impacts of nonlinear loads on power quality in commercial buildings-An overview","authors":"K. Johnson, R. Zavadil","doi":"10.1109/IAS.1991.178115","DOIUrl":"https://doi.org/10.1109/IAS.1991.178115","url":null,"abstract":"The characteristics and effects of nonlinear loads in the commercial office environment are discussed. The interaction of distorted currents drawn by these loads with the power system are described. An approximate approach for evaluating potential problems within a given facility is discussed, which, while not rigorous, can be used as a screening tool by building designers and engineers to make assessments of the potential for harmonic problems. Effects of high relative levels of harmonic current generation in commercial buildings include harmonic voltage distortion, transformer and motor overheating, and neutral conductor overloading. Reasonable estimates of the impacts of nonlinear loads can be made from generalized harmonic current source characteristics of three basic nonlinear types. Interactions with the electric power system can be predicted with simplified representations of the building electrical system.<<ETX>>","PeriodicalId":294244,"journal":{"name":"Conference Record of the 1991 IEEE Industry Applications Society Annual Meeting","volume":"54 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":"133690786","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}
In order to produce a comfortable luminous environment, 1/f fluctuation control of illuminance is proposed. It is shown that natural light which is comfortable to humans, such as sunlight streaming through leaves toward the ground, has 1/f fluctuation characteristics. On the other hand, artificial lights such as fluorescent lamps have near white-noise characteristics at frequencies below 10 Hz. It is also shown that the same fluctuation of natural light can be easily reproduced artificially by fluctuating the pulse width of the inverter output voltage. It is expected that 1/f fluctuation control of light can be applied to relaxation rooms in offices, hospitals, or schools to produce comfortable and relaxing environments for humans.<>
{"title":"1/f fluctuation control of illuminance for comfortable luminous environments","authors":"K. Oguchi, H. Tsukamoto, H. Seki, M. Agu","doi":"10.1109/IAS.1991.178116","DOIUrl":"https://doi.org/10.1109/IAS.1991.178116","url":null,"abstract":"In order to produce a comfortable luminous environment, 1/f fluctuation control of illuminance is proposed. It is shown that natural light which is comfortable to humans, such as sunlight streaming through leaves toward the ground, has 1/f fluctuation characteristics. On the other hand, artificial lights such as fluorescent lamps have near white-noise characteristics at frequencies below 10 Hz. It is also shown that the same fluctuation of natural light can be easily reproduced artificially by fluctuating the pulse width of the inverter output voltage. It is expected that 1/f fluctuation control of light can be applied to relaxation rooms in offices, hospitals, or schools to produce comfortable and relaxing environments for humans.<<ETX>>","PeriodicalId":294244,"journal":{"name":"Conference Record of the 1991 IEEE Industry Applications Society Annual Meeting","volume":"15 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":"133570489","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 propose the robust force and control of a DD motor based on a novel model following acceleration control. The model following acceleration control system has the ability to suppress the state error caused by not only force disturbance but also system structure variations. The DD motor controlled by the proposed acceleration control system is treated as a structure of two integral elements, which has no mechanical system parameter. Therefore, each joint of a DD robot manipulator is regulated by an acceleration command. The proposed acceleration control system is designed using H/sup infinity / control theory, and it is realized by a DSP (digital signal processor) software algorithm. Experimental results show that the proposed method is valid for the robust force and compliance control system of a DD robot manipulator.<>
{"title":"DSP-based robust force and compliance control of DD motor","authors":"K. Ohishi, S. Matsuda","doi":"10.1109/IAS.1991.178093","DOIUrl":"https://doi.org/10.1109/IAS.1991.178093","url":null,"abstract":"The authors propose the robust force and control of a DD motor based on a novel model following acceleration control. The model following acceleration control system has the ability to suppress the state error caused by not only force disturbance but also system structure variations. The DD motor controlled by the proposed acceleration control system is treated as a structure of two integral elements, which has no mechanical system parameter. Therefore, each joint of a DD robot manipulator is regulated by an acceleration command. The proposed acceleration control system is designed using H/sup infinity / control theory, and it is realized by a DSP (digital signal processor) software algorithm. Experimental results show that the proposed method is valid for the robust force and compliance control system of a DD robot manipulator.<<ETX>>","PeriodicalId":294244,"journal":{"name":"Conference Record of the 1991 IEEE Industry Applications Society Annual Meeting","volume":"310 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":"133771205","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 electric curtain consisting of a parallel cylindrical electrodes was constructed. An electric field of standing wave type was produced with superposition of both single-phase AC and DC voltage. Although each particle showed a stationary up-and-down motion within a confined region, as a whole fan-like pattern of particle motion was observed over electrodes. The shape of the pattern was changed with the applied voltage of either AC or DC, or both. The measurement of the amount of charge of suspended particles showed that the particles over grounded electrodes have a positive polarity and the particles over high voltage electrodes have a negative one.<>
{"title":"Fundamental study of the motion of charged powder particles by using electric curtain","authors":"K. Asano, Y. Banno, K. Yatsuzuka, Y. Higashiyama","doi":"10.1109/IAS.1991.178203","DOIUrl":"https://doi.org/10.1109/IAS.1991.178203","url":null,"abstract":"The electric curtain consisting of a parallel cylindrical electrodes was constructed. An electric field of standing wave type was produced with superposition of both single-phase AC and DC voltage. Although each particle showed a stationary up-and-down motion within a confined region, as a whole fan-like pattern of particle motion was observed over electrodes. The shape of the pattern was changed with the applied voltage of either AC or DC, or both. The measurement of the amount of charge of suspended particles showed that the particles over grounded electrodes have a positive polarity and the particles over high voltage electrodes have a negative one.<<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":"116553337","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 high voltage source generating the fast rising square wave voltage has been developed for a high efficiency ozone generator. The voltage source incorporated a rotating spark gap switch. Lifetime of the voltage source is determined by erosion of the spark gap switch. In order to obtain a long life time, various electrode materials have been experimentally tested. Sintered tungsten with thorium dioxide has the smallest erosion rate among the materials tested in the experiment. Using this material as the switch, the high voltage source was constructed to operate an ozone generator with an ozone generating rate of 20 g/h.<>
{"title":"Pulsed high voltage source for ozone generator","authors":"Y. Kamase, M. Shimizu, T. Nagahama, A. Mizuno","doi":"10.1109/IAS.1991.178312","DOIUrl":"https://doi.org/10.1109/IAS.1991.178312","url":null,"abstract":"A high voltage source generating the fast rising square wave voltage has been developed for a high efficiency ozone generator. The voltage source incorporated a rotating spark gap switch. Lifetime of the voltage source is determined by erosion of the spark gap switch. In order to obtain a long life time, various electrode materials have been experimentally tested. Sintered tungsten with thorium dioxide has the smallest erosion rate among the materials tested in the experiment. Using this material as the switch, the high voltage source was constructed to operate an ozone generator with an ozone generating rate of 20 g/h.<<ETX>>","PeriodicalId":294244,"journal":{"name":"Conference Record of the 1991 IEEE Industry Applications Society Annual Meeting","volume":"86 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":"116742533","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 family of nonintrusive methods is presented for estimating the shaft angle of a switched reluctance machine. Such methods can be utilized for commutation control of the SRM (switched reluctance machine) thereby eliminating the requirement for a shaft position sensor. These methods rely on the machine's inherent flux/current magnetic characteristics to infer rotor position from measurements of stator flux-linkage and current during normal phase excitation. Position estimation schemes are presented for SRMs in which both single and multiple simultaneous phases are excited. Also presented is a simulated sensing performance using measured SRM data processed according to the proposed position lumped-parameter estimation scheme.<>
{"title":"Flux-current methods for SRM rotor position estimation","authors":"J. Lyons, S. R. Macminn, M. A. Preston","doi":"10.1109/IAS.1991.178199","DOIUrl":"https://doi.org/10.1109/IAS.1991.178199","url":null,"abstract":"A family of nonintrusive methods is presented for estimating the shaft angle of a switched reluctance machine. Such methods can be utilized for commutation control of the SRM (switched reluctance machine) thereby eliminating the requirement for a shaft position sensor. These methods rely on the machine's inherent flux/current magnetic characteristics to infer rotor position from measurements of stator flux-linkage and current during normal phase excitation. Position estimation schemes are presented for SRMs in which both single and multiple simultaneous phases are excited. Also presented is a simulated sensing performance using measured SRM data processed according to the proposed position lumped-parameter estimation scheme.<<ETX>>","PeriodicalId":294244,"journal":{"name":"Conference Record of the 1991 IEEE Industry Applications Society Annual Meeting","volume":"18 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":"114646448","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 analysis presented shows that a variable frequency power supply can be used for speed control of single-phase induction motors which are equipped with auxiliary windings and capacitors. Using the standard scalar control technique for three-phase induction motors on the capacitor motor works best at relatively high frequencies, but the torque must be derated below about 50% of base frequency to yield a sufficient margin from breakdown torque and to prevent overheating the machine. The torque performance of the capacitor motors can be enhanced by altering the voltage-frequency control law. One method that provides good results is to control the voltage such that the internal power dissipation in the motor is held constant.<>
{"title":"Operating characteristics of single-phase capacitor motors driven from variable frequency supplies","authors":"E. R. Collins, R. Ashley","doi":"10.1109/IAS.1991.178132","DOIUrl":"https://doi.org/10.1109/IAS.1991.178132","url":null,"abstract":"The analysis presented shows that a variable frequency power supply can be used for speed control of single-phase induction motors which are equipped with auxiliary windings and capacitors. Using the standard scalar control technique for three-phase induction motors on the capacitor motor works best at relatively high frequencies, but the torque must be derated below about 50% of base frequency to yield a sufficient margin from breakdown torque and to prevent overheating the machine. The torque performance of the capacitor motors can be enhanced by altering the voltage-frequency control law. One method that provides good results is to control the voltage such that the internal power dissipation in the motor is held constant.<<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":"114740840","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}
An IGBT (insulated-gate bipolar transistor)-bipolar discrete Darlington power switch is presented. The main high-current bipolar power switch is driven by a lower current IGBT, yielding a switch with low drive requirements and high current handling capacity. The power dissipation is lower than that of a MOS-bipolar Darlington. The behavior of such a switch is investigated using discrete device models and an important parasitic network. Some of the important design parameters of the switch and drive circuit are discussed together with possible ways of improving circuit performance. Some aspects of protection and paralleling are also presented. The analysis and discussions are supported by oscillograms from laboratory experiments.<>
{"title":"IGBT-bipolar discrete Darlington power switches: performance and design","authors":"S. Biswas, B. Basak, K. Rajashekara","doi":"10.1109/IAS.1991.178056","DOIUrl":"https://doi.org/10.1109/IAS.1991.178056","url":null,"abstract":"An IGBT (insulated-gate bipolar transistor)-bipolar discrete Darlington power switch is presented. The main high-current bipolar power switch is driven by a lower current IGBT, yielding a switch with low drive requirements and high current handling capacity. The power dissipation is lower than that of a MOS-bipolar Darlington. The behavior of such a switch is investigated using discrete device models and an important parasitic network. Some of the important design parameters of the switch and drive circuit are discussed together with possible ways of improving circuit performance. Some aspects of protection and paralleling are also presented. The analysis and discussions are supported by oscillograms from laboratory experiments.<<ETX>>","PeriodicalId":294244,"journal":{"name":"Conference Record of the 1991 IEEE Industry Applications Society Annual Meeting","volume":"31 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":"116559881","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}
In addition to high reliability, coverage, error latency, and retry time are important factors in the design of fault tolerant computer systems. In the proposed architecture, an error-reporting circuit and a faulty address latch are designed to detect the failure and to minimize the retry time, respectively. The MIL-HDBK-217E model is used to predict the failure rates of system module, processor module, memory module, and hard core. It is shown that the mission time improvement factor of the proposed system is almost independent of a given reliability. A Markov process model is used to evaluate the reliability and analyze the coverage, the error latency, and the retry time of the proposed system. The proposed architecture possesses short retry time, high reliability, high coverage, low error latency, and is well suited for real-time industry applications.<>
{"title":"On designing and evaluating a high reliability microcomputer system for real-time industry applications","authors":"Yen-Tseng Hsu, Chen-Fa Hsu","doi":"10.1109/IAS.1991.178096","DOIUrl":"https://doi.org/10.1109/IAS.1991.178096","url":null,"abstract":"In addition to high reliability, coverage, error latency, and retry time are important factors in the design of fault tolerant computer systems. In the proposed architecture, an error-reporting circuit and a faulty address latch are designed to detect the failure and to minimize the retry time, respectively. The MIL-HDBK-217E model is used to predict the failure rates of system module, processor module, memory module, and hard core. It is shown that the mission time improvement factor of the proposed system is almost independent of a given reliability. A Markov process model is used to evaluate the reliability and analyze the coverage, the error latency, and the retry time of the proposed system. The proposed architecture possesses short retry time, high reliability, high coverage, low error latency, and is well suited for real-time industry applications.<<ETX>>","PeriodicalId":294244,"journal":{"name":"Conference Record of the 1991 IEEE Industry Applications Society Annual Meeting","volume":"79 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":"123710657","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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