Pub Date : 2012-10-01DOI: 10.11142/JICEMS.2013.2.2.141
K. Imamura, M. Sanada, S. Morimoto, Y. Inoue
Permanent magnet (PM) motors that employ rare-earth magnets containing dysprosium (Dy) are used in electric and hybrid electric vehicles. However, it is desirable to reduce the amount of Dy used since it is expensive. This study investigates the rotor structure of a PM synchronous motor with a Dy-free rare-earth magnet. Flux barrier shapes and PM thicknesses that enhance the irreversible demagnetization are investigated. In addition, a rotor structure that improves the irreversible demagnetization is proposed. We demonstrate that the proposed rotor structure without Dy improves the irreversible demagnetization.
{"title":"Improvement of demagnetization by rotor structure of IPMSM with Dy-free rare-earth magnet","authors":"K. Imamura, M. Sanada, S. Morimoto, Y. Inoue","doi":"10.11142/JICEMS.2013.2.2.141","DOIUrl":"https://doi.org/10.11142/JICEMS.2013.2.2.141","url":null,"abstract":"Permanent magnet (PM) motors that employ rare-earth magnets containing dysprosium (Dy) are used in electric and hybrid electric vehicles. However, it is desirable to reduce the amount of Dy used since it is expensive. This study investigates the rotor structure of a PM synchronous motor with a Dy-free rare-earth magnet. Flux barrier shapes and PM thicknesses that enhance the irreversible demagnetization are investigated. In addition, a rotor structure that improves the irreversible demagnetization is proposed. We demonstrate that the proposed rotor structure without Dy improves the irreversible demagnetization.","PeriodicalId":6398,"journal":{"name":"2012 15th International Conference on Electrical Machines and Systems (ICEMS)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78014512","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 : 2012-10-01DOI: 10.5370/JEET.2013.8.6.1415
J. Ro, K. Yi, Hyun-Kyo Jung
The traveling wave ultra-sonic motor (TWUSM) is operated through the frictional force between the rotor and the stator. Hence, the contact mechanism must be analyzed to estimate the performance of the motor. However, the nonlinearity of the contact mechanism of the TWUSM makes it difficult to suggest a proper contact model and a characteristic analysis method. To address these problems, a novel contact model is proposed here. It is termed the cylindrical dynamic contact model (CDCM) in this research. A motor performance estimation method is suggested using the CDCM, an analytical method, and a numerical method. The feasibility and usefulness of the suggested characteristic analysis are verified through experimental data.
{"title":"Characteristic analysis of an traveling wave ultrasonic motor using the cylindrical dynamic contact model","authors":"J. Ro, K. Yi, Hyun-Kyo Jung","doi":"10.5370/JEET.2013.8.6.1415","DOIUrl":"https://doi.org/10.5370/JEET.2013.8.6.1415","url":null,"abstract":"The traveling wave ultra-sonic motor (TWUSM) is operated through the frictional force between the rotor and the stator. Hence, the contact mechanism must be analyzed to estimate the performance of the motor. However, the nonlinearity of the contact mechanism of the TWUSM makes it difficult to suggest a proper contact model and a characteristic analysis method. To address these problems, a novel contact model is proposed here. It is termed the cylindrical dynamic contact model (CDCM) in this research. A motor performance estimation method is suggested using the CDCM, an analytical method, and a numerical method. The feasibility and usefulness of the suggested characteristic analysis are verified through experimental data.","PeriodicalId":6398,"journal":{"name":"2012 15th International Conference on Electrical Machines and Systems (ICEMS)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76849357","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 : 2012-10-01DOI: 10.1299/jsmeenv.2012.22.374
M. Okuda, S. Obara, R. Shimizu
Focused on the differential pressure at the time of generation of gas hydrate dissociation, we develop a power generator by the high-pressure gas. CO2 hydrate generates from fluid mixture of pure water and CO2. Furthermore, heating of CO2 hydrate will generate the high pressure gas by dissociation. Filling 3 MPa CO2 gas poured into 50ml water as an initial condition, repeating the cooling and heating between -5 °C and 30 °C it, can be obtained continuously a pressure differential of about 0.7 MPa.
{"title":"Fundamental examination on the dissociation and expansion characteristics of CO2 hydrate using the gas-hydrate generator","authors":"M. Okuda, S. Obara, R. Shimizu","doi":"10.1299/jsmeenv.2012.22.374","DOIUrl":"https://doi.org/10.1299/jsmeenv.2012.22.374","url":null,"abstract":"Focused on the differential pressure at the time of generation of gas hydrate dissociation, we develop a power generator by the high-pressure gas. CO<sub>2</sub> hydrate generates from fluid mixture of pure water and CO<sub>2</sub>. Furthermore, heating of CO<sub>2</sub> hydrate will generate the high pressure gas by dissociation. Filling 3 MPa CO<sub>2</sub> gas poured into 50ml water as an initial condition, repeating the cooling and heating between -5 °C and 30 °C it, can be obtained continuously a pressure differential of about 0.7 MPa.","PeriodicalId":6398,"journal":{"name":"2012 15th International Conference on Electrical Machines and Systems (ICEMS)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84275796","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 : 2012-10-01DOI: 10.11142/JICEMS.2014.3.3.331
Y. Yoshida, H. Suzuki, K. Fujiwara, Y. Ishihara
When large penetration of the distributed generators (DGs) such as photovoltaic (PV) systems is growing up in grid system, it is important to quickly prevent islanding caused by power system fault in order to ensure electrical safety. We propose a novel active method for islanding prevention by harmonic injection synchronized with exciting current harmonics of the pole transformer in order to avoid mutual interference between active signals. We confirm the validity of the proposed method by performing the basic tests of islanding by using a current source superimposed the harmonic active signal. Further, we carry out the simulation using PSCAD/EMTDC, and verify the fast detection of islanding.
{"title":"Islanding prevention method for photovoltaic system by harmonic injection synchronized to exciting current harmonics of pole transformer","authors":"Y. Yoshida, H. Suzuki, K. Fujiwara, Y. Ishihara","doi":"10.11142/JICEMS.2014.3.3.331","DOIUrl":"https://doi.org/10.11142/JICEMS.2014.3.3.331","url":null,"abstract":"When large penetration of the distributed generators (DGs) such as photovoltaic (PV) systems is growing up in grid system, it is important to quickly prevent islanding caused by power system fault in order to ensure electrical safety. We propose a novel active method for islanding prevention by harmonic injection synchronized with exciting current harmonics of the pole transformer in order to avoid mutual interference between active signals. We confirm the validity of the proposed method by performing the basic tests of islanding by using a current source superimposed the harmonic active signal. Further, we carry out the simulation using PSCAD/EMTDC, and verify the fast detection of islanding.","PeriodicalId":6398,"journal":{"name":"2012 15th International Conference on Electrical Machines and Systems (ICEMS)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89619257","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 : 2012-10-01DOI: 10.11142/JICEMS.2013.2.1.69
Shouhua Zhao, Lin Cui, Guiying Liu, Yangsheng Chen
This paper is concerned with speed tracking control problem for permanent-magnet synchronous drives (PMSM) in the presence of an variable load torque and unknown model parameters. The disturbance of speed control caused by inaccuracy of model parameters has been investigated. A load torque observer has been proposed to observe the load torque and estimate the disturbance caused by inaccuracy of model parameters. Both inertia and friction coefficient are identified in gradient descent approach. The stability condition of the observer has also been studied. Furthermore an improved feed-forward control has been introduced to reduce the speed track error. The proposed control strategy has been verified by both simulation and experimental results.
{"title":"An improved torque feed-forward control with observer-based inertia identification in PMSM drives","authors":"Shouhua Zhao, Lin Cui, Guiying Liu, Yangsheng Chen","doi":"10.11142/JICEMS.2013.2.1.69","DOIUrl":"https://doi.org/10.11142/JICEMS.2013.2.1.69","url":null,"abstract":"This paper is concerned with speed tracking control problem for permanent-magnet synchronous drives (PMSM) in the presence of an variable load torque and unknown model parameters. The disturbance of speed control caused by inaccuracy of model parameters has been investigated. A load torque observer has been proposed to observe the load torque and estimate the disturbance caused by inaccuracy of model parameters. Both inertia and friction coefficient are identified in gradient descent approach. The stability condition of the observer has also been studied. Furthermore an improved feed-forward control has been introduced to reduce the speed track error. The proposed control strategy has been verified by both simulation and experimental results.","PeriodicalId":6398,"journal":{"name":"2012 15th International Conference on Electrical Machines and Systems (ICEMS)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80984254","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 : 2012-10-01DOI: 10.11142/JICEMS.2013.2.2.184
T. Iwata, S. Morimoto, Y. Inoue, M. Sanada
This paper proposes a method for improving the performance of a position sensorless control system for a slotless surface permanent magnet synchronous motor (SPMSM) in a very low-speed region. In position sensorless control based on a motor model, accurate motor parameters are required because parameter errors would affect position estimation accuracy. Therefore, online parameter identification is used. The error between the reference voltage and the voltage applied to the motor is compensated to ensure accuracy and stability of the sensorless control system. In this study, two voltage error compensation methods are used: compensation method 1, which is the conventional method and compensation method 2, which is the proposed method. In the proposed method, online parameter identification and compensation method 2 are used. The proposed method is evaluated by experimental results.
{"title":"Study of performance improvement of slotless SPMSM position sensorless control in very low-speed region","authors":"T. Iwata, S. Morimoto, Y. Inoue, M. Sanada","doi":"10.11142/JICEMS.2013.2.2.184","DOIUrl":"https://doi.org/10.11142/JICEMS.2013.2.2.184","url":null,"abstract":"This paper proposes a method for improving the performance of a position sensorless control system for a slotless surface permanent magnet synchronous motor (SPMSM) in a very low-speed region. In position sensorless control based on a motor model, accurate motor parameters are required because parameter errors would affect position estimation accuracy. Therefore, online parameter identification is used. The error between the reference voltage and the voltage applied to the motor is compensated to ensure accuracy and stability of the sensorless control system. In this study, two voltage error compensation methods are used: compensation method 1, which is the conventional method and compensation method 2, which is the proposed method. In the proposed method, online parameter identification and compensation method 2 are used. The proposed method is evaluated by experimental results.","PeriodicalId":6398,"journal":{"name":"2012 15th International Conference on Electrical Machines and Systems (ICEMS)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73597587","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 : 2012-10-01DOI: 10.11142/JICEMS.2013.2.2.225
M. N. Ambia, A. Al‐Durra, Cedric Caruana, S. Muyeen
Low voltage ride through capability augmentation of a hybrid micro-grid system is presented in this paper which reflects enhanced reliability in the system. The control scheme involves parallel connected multiple ac-dc bidirectional converters. When the micro-grid system is subjected to a severe voltage dip by any transient fault single power converter may not be able to provide necessary reactive power to overcome the severe voltage dip. This paper discusses the control strategy of additional power converter connected in parallel with main converter to support extra reactive power to withstand the severe voltage dip. During transient fault, when the terminal voltage crosses 90% of its pre-fault value, additional converter comes into operation. With the help of additional power converter, the micro-grid system withstands the severe voltage fulfilling the grid code requirements. This multiple converter scheme provides the micro-grid system the capability of low voltage ride through which makes the system more reliable and stable.
{"title":"Stability enhancement of a hybrid micro-grid system in grid fault condition","authors":"M. N. Ambia, A. Al‐Durra, Cedric Caruana, S. Muyeen","doi":"10.11142/JICEMS.2013.2.2.225","DOIUrl":"https://doi.org/10.11142/JICEMS.2013.2.2.225","url":null,"abstract":"Low voltage ride through capability augmentation of a hybrid micro-grid system is presented in this paper which reflects enhanced reliability in the system. The control scheme involves parallel connected multiple ac-dc bidirectional converters. When the micro-grid system is subjected to a severe voltage dip by any transient fault single power converter may not be able to provide necessary reactive power to overcome the severe voltage dip. This paper discusses the control strategy of additional power converter connected in parallel with main converter to support extra reactive power to withstand the severe voltage dip. During transient fault, when the terminal voltage crosses 90% of its pre-fault value, additional converter comes into operation. With the help of additional power converter, the micro-grid system withstands the severe voltage fulfilling the grid code requirements. This multiple converter scheme provides the micro-grid system the capability of low voltage ride through which makes the system more reliable and stable.","PeriodicalId":6398,"journal":{"name":"2012 15th International Conference on Electrical Machines and Systems (ICEMS)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79693917","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 : 2012-10-01DOI: 10.11142/JICEMS.2013.2.2.127
H. Kakihata, Y. Kataoka, M. Takayama, Y. Matsushima, Y. Anazawa
In this paper, the authors designed a surface permanent magnet (SPM)-type vernier motor whose maximum output is more than 5.2 kW, whose power factor at 4 kW is more than 90%, and whose efficiency at 4 kW is 85% under the conditions that the operating voltage, frequency, and synchronous speed are 400 V, 50 Hz, and 100 min-1, respectively.
{"title":"Design of surface permanent magnet-type vernier motor","authors":"H. Kakihata, Y. Kataoka, M. Takayama, Y. Matsushima, Y. Anazawa","doi":"10.11142/JICEMS.2013.2.2.127","DOIUrl":"https://doi.org/10.11142/JICEMS.2013.2.2.127","url":null,"abstract":"In this paper, the authors designed a surface permanent magnet (SPM)-type vernier motor whose maximum output is more than 5.2 kW, whose power factor at 4 kW is more than 90%, and whose efficiency at 4 kW is 85% under the conditions that the operating voltage, frequency, and synchronous speed are 400 V, 50 Hz, and 100 min-1, respectively.","PeriodicalId":6398,"journal":{"name":"2012 15th International Conference on Electrical Machines and Systems (ICEMS)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89415474","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 : 2012-10-01DOI: 10.11142/JICEMS.2013.2.1.104
Liu Junqiao, M. Rosyadi, R. Takahashi, J. Tamura, T. Fukushima, A. Sakahara, K. Shinya, K. Yosioka
In this paper a centralized pitch angle controller for fixed speed wind turbines based wind farm is proposed to mitigate load frequency fluctuation. Reference signal for the pitch angle of each wind turbine is calculated based on the proposed centralized control system using wind speed information. The multi machine power system model composed of 4 synchronous generators and a load, to which a wind farm is connected, is used in the analysis. Simulation analyses have been carried out to investigate the performance of the controller using real wind speed data. It is concluded that the load frequency of the system can be controlled smoothly.
{"title":"Mitigation of load frequency fluctuation using a centralized pitch angle control of wind turbines","authors":"Liu Junqiao, M. Rosyadi, R. Takahashi, J. Tamura, T. Fukushima, A. Sakahara, K. Shinya, K. Yosioka","doi":"10.11142/JICEMS.2013.2.1.104","DOIUrl":"https://doi.org/10.11142/JICEMS.2013.2.1.104","url":null,"abstract":"In this paper a centralized pitch angle controller for fixed speed wind turbines based wind farm is proposed to mitigate load frequency fluctuation. Reference signal for the pitch angle of each wind turbine is calculated based on the proposed centralized control system using wind speed information. The multi machine power system model composed of 4 synchronous generators and a load, to which a wind farm is connected, is used in the analysis. Simulation analyses have been carried out to investigate the performance of the controller using real wind speed data. It is concluded that the load frequency of the system can be controlled smoothly.","PeriodicalId":6398,"journal":{"name":"2012 15th International Conference on Electrical Machines and Systems (ICEMS)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74962579","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 : 2012-10-01DOI: 10.11142/JICEMS.2014.3.1.98
G. Islam, A. Al‐Durra, C. Caruna, S. Muyeen, J. Tamura
This paper presents the performance of a sliding mode based hybrid controller for three phase voltage source inverter. The main objective of this analysis is to observe the effectiveness of the controller for fault ride through (FRT) capability improvement of the DC based distributed generations (DG). The performance of the conventional PI based cascaded controller is also presented for comparison purpose.
{"title":"Performance analysis of a sliding mode control for distributed generations","authors":"G. Islam, A. Al‐Durra, C. Caruna, S. Muyeen, J. Tamura","doi":"10.11142/JICEMS.2014.3.1.98","DOIUrl":"https://doi.org/10.11142/JICEMS.2014.3.1.98","url":null,"abstract":"This paper presents the performance of a sliding mode based hybrid controller for three phase voltage source inverter. The main objective of this analysis is to observe the effectiveness of the controller for fault ride through (FRT) capability improvement of the DC based distributed generations (DG). The performance of the conventional PI based cascaded controller is also presented for comparison purpose.","PeriodicalId":6398,"journal":{"name":"2012 15th International Conference on Electrical Machines and Systems (ICEMS)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76462061","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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