• Title, Summary, Keyword: Torque

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Comparison of the torque stability of Implant Torque Controllers

  • Kim, Dae-Gon;Cho, Lee-Ra;Park, Chan-Jin
    • Journal of Korean Dental Science
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    • v.2 no.1
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    • pp.19-27
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    • 2009
  • Tightening of the screws in implant restorations should be accurate and precise. If applied torque is too low, screw loosening would be occurred. With too high torque, the screw fracture might take place. Various torque generating devices are developed and employed to apply a proper torque. The purpose of this investigation was to determine and compare the accuracy of the torque controllers. In this study, 4 types of torque controllers were used; electronic torque controller, torque limiting device, torque indicating device and contra angle torque driver. Digital torque gauge was employed to measure the de-torque value. Thirty cycles of tightening and loosening were done with each torque controller. All implant torque controllers have shown slight errors and deviations. The torque liming device exhibited the most accurate data. No significant difference was found among the mean de-torque values of the electronic torque controller, torque indicating device and contra angle torque driver. In the limitation of this study, it would be recommended that the implant torque controllers should be checked whether uniformed and precise torque can be generated and a measuring error should be corrected.

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Load Control Device for VVVF Inverter Testing (인버터 시험을 위한 부하제어 장치)

  • Kim, Gil-Dong;Lee, Han-Min
    • Proceedings of the KSR Conference
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    • pp.675-679
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    • 2007
  • The control method of programmable dynamometer for overall test of machine is to load reference torque which is computed from torque transducer into motor under test. But the torque information detected from torque transducer have a lot of noise when the load torque of moter is a small quantity or changing. Thus, torque transducer must have a low pass filter to detect a definite torque information. But The torque delay generated by filter with torque transducer occur a torque trouble for moter torque of programmable dynamometer. Therefore, this kind of system could not perform dynamic and nonlinear load. In this paper, the control method using the load torque observer without a measure for torque transducer is proposed. The proposed system improved the problem of the torque measuring delay with torque transducer, and the load torque is estimated by the minimal order state observer based on the torque component of the vector control induction moter. Therefore, the torque controller is not affected by a load torque disturbance.

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Improved Programmable-Dynamometer Control For Traction Drive System Testing (견인구동시스템 시험을 위한 개선된 프로그램어블 다이나모메터 제어)

  • Kim G.D;Hong J.S;Shin J.R;Lee W.D;Han S.Y
    • Proceedings of the KSR Conference
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    • pp.427-432
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    • 2003
  • The control method of programmable dynamometer for overall test of machine is to load the reference torque which is computed from torque transducer into motor under test. But the torque information detected from torque transducer have a lot of noise when the load torque of moter is a small quantity or changing. Thus, torque transducer must have a low pass filter to detect a definite torque information. But The torque delay generated by filter with torque transducer occur a torque trouble for meter torque of programmable dynamometer. The proposed system improved the problem of the torque measuring delay with torque transducer, and the load torque is estimated by the minimal order state observer based on the torque component of the vector control induction meter. Therefore, the torque controller is not affected by a load torque disturbance.

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Programmable-Dynamometer Control For Traction Motor Testing (전동기 시험을 위한 프로그램어블 다이나오메터 제어)

  • Kim, G.D.;Hong, J.S.;Ahn, T.K.;Lee, H.Y.;Shin, J.R.;Han, S.Y.
    • Proceedings of the KIEE Conference
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    • pp.1108-1110
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    • 2003
  • The control method of programmable dynamometer for overall test of machine is to load the reference torque which is computed from torque transducer into motor under test. But the torque information detected from torque transducer have a lot of noise when the load torque of meter is a small quantity or changing. Thus, torque transducer must have a low pass filter to detect a definite torque information. But The torque delay generated by filter with torque transducer occur a torque trouble for meter torque of programmable dynamometer. The proposed system improved the problem of the torque measuring delay with torque transducer, and the load torque is estimated by the minimal order state observer based on the torque component of the vector control induction moter. Therefore, the torque controller is not affected by a load torque disturbance.

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A Improved Programmable-Dynamometer Control For Motor Drive Systems Testing (모터 구동시스템 시험을 위한 개선된 프로그램어블 다이나모메터 제어)

  • 김길동;박현준;조정민;전기영;오봉환;이훈구;한경희
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.52 no.5
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    • pp.211-220
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    • 2003
  • The control method of programmable dynamometer for overall test of machine is to load the reference torque which is computed from torque transducer into motor under test. But the torque information detected from torque transducer have a lot of noise when the load torque of meter is a small quantity or changing. Thus, torque transducer must have a low pass filter to detect a definite torque information. But The torque delay generated by filter with torque transducer occur a torque trouble for meter torque of programmable dynamometer. Therefore, this kind of system could not perform dynamic and nonlinear load. In this paper, the control method using the load torque observer without a measure for torque transducer is Proposed. The proposed system improved the problem of the torque measuring delay with torque transducer, and the load torque is estimated by the minimal order state observer based on the torque component of the vector control induction meter. Therefore, the torque controller is not affected by a load torque disturbance. To verify a superiority of the proposed control algorithm, the analysis for a root locus of a conventional control method and the proposed one, and simulation and experiment is performed. Therefore we hope to be extended in industrial application.

A Highly Efficient Dynamometer Control For Motor Drive Systems Testing (구동 시스템 시험을 위한 고성능 다이나모메터 제어)

  • Kim Gil-Dong;Shin Jeong-Ryol;Lee Han-Min;Lee Woo-Dong
    • Proceedings of the KIEE Conference
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    • pp.1291-1293
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    • 2004
  • The control method of programmable dynamometer for overall test of machine is to load the reference torque which is computed from torque transducer into motor under test. But the torque information detected from torque transducer have a lot of noise when the load torque of meter is a small quantity or changing. Thus, torque transducer must have a low pass filter to detect a definite torque information. But The torque delay generated by filter with torque transducer occur a torque trouble for moter torque of programmable dynamometer. Therefore, this kind of system could not perform dynamic and nonlinear load. In this paper, the control method using the load torque observer without a measure for torque transducer is proposed. The proposed system improved the problem of the torque measuring delay with torque transducer, and the load torque is estimated by the minimal order state observer based on the torque component of the vector control induction meter. Therefore, the torque controller is not affected by a load torque disturbance.

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Comparison of Accuracy of Implant Torque Controllers (수종의 임플란트 토크 조절기의 정확성 비교)

  • Kim, Dae-Gon;Cho, Lee-Ra;Park, Chan-Jin
    • Journal of Dental Rehabilitation and Applied Science
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    • v.24 no.2
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    • pp.157-168
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    • 2008
  • Tightening of the screws in implant restorations should be accurate and precise. If applied torque is too low, screw loosening would be occurred. With too high torque, the screw fracture might take place. Various torque generating devices are developed and employed to apply a proper torque. The purpose of this investigation was to determine and compare the accuracy of the torque controllers. In this study, 4 types of torque controllers were used; electronic torque controller, torque limiting device, torque indicating device and contra angle torque driver. Digital torque gauge was employed to measure the de-torque value. Thirty cycles of tightening and loosening were done with each torque controller. All implant torque controllers have shown slight errors and deviations. The torque liming device exhibited the most accurate data. No significant difference was found among the mean de-torque values of the electronic torque controller, torque indicating device and contra angle torque driver. In the limitation of this study, it would be recommended that the implant torque controllers should be checked whether uniformed and precise torque can be generated and a measuring error should be corrected.

Direct Torque Control Scheme of Switched Reluctance Motor using Novel Torque Sharing Function (토크분배함수를 이용한 SRM의 적접토크제어기법)

  • Ahn, Jin-Woo;Lee, Dong-Hee;Kim, Tae-Hyoung;Liang, Jianing
    • Proceedings of the KIEE Conference
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    • pp.138-140
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    • 2007
  • A novel non-linear logical torque sharing function (TSF) is presented. To improve efficiency and to reduce torque ripple in commutation region, only a phase torque under commutation is regulated to produce a uniform torque. And the torque developed by the other phase remains with the previous state under a current limit of the motor and drive. If the minimum change of a phase torque reference can not satisfy the total reference torque, two-phase changing mode is used. Since a phase torque is constant and the other phase torque is changed at each rotor position, total torque error can be reduced within a phase torque error limit. And the total torque error is dependent on the change of phase torque. To consider non-linear torque characteristics and to suppress a tail current at the end of commutation region, the incoming phase current is changed to torque increasing direction, but the outgoing phase current is changed to torque decreasing direction. So, the torque sharing of the outgoing phase and incoming phase can be smoothly changed with a minimum current cross over. The proposed control scheme is verified by some computer simulations and experimental results.

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Torque Sharing Function of SRM for Torque Ripple Reduction in Commutation Region (커뮤테이션 구간의 토크리플 저감을 위한 SRM의 토크 분배 함수 기법)

  • Kim, Tae-Hyoung;Wang, Huijun;Lee, Dong-Hee;Ahn, Jin-Woo
    • Proceedings of the KIPE Conference
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    • pp.148-150
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    • 2007
  • A novel torque sharing function (TSF) is presented. To improve efficiency and to reduce torque ripple in commutation region, only a phase torque under commutation is regulated to produce a uniform torque. And the torque developed by the other phase remains with the previous state under a current limit of the motor and drive. If the minimum change of a phase torque reference can not satisfy the total reference torque, two-phase changing mode is used. Since a phase torque is constant and the other phase torque is changed at each rotor position, total torque error can be reduced within a phase torque error limit. And the total torque error is dependent on the change of phase torque. To consider non-linear torque characteristics and to suppress a tail current at the end of commutation region, the incoming phase current is changed to torque increasing direction, but the outgoing phase current is changed to torque decreasing direction. So, the torque sharing of the outgoing phase and incoming phase can be smoothly changed with a minimum current cross over. The proposed control scheme is verified by some computer simulations and experimental results.

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Dynamic Response of a 2.75MW Wind Turbine Applying Torque Control Method Based on Torque-Mode (토크모드 기반의 토크 제어 방법을 적용한 2.75MW 풍력터빈의 동적 응답)

  • Lim, Chae-Wook
    • The KSFM Journal of Fluid Machinery
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    • v.16 no.6
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    • pp.5-11
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    • 2013
  • Torque control methods of wind turbine are mainly classified into two methods: torque-mode and speed-mode methods. The traditional torque-mode method, in which generator torque proportional to square of generator speed is determined, has been chosen in many wind turbines but its response is slower as they are larger in multi-MW size. Torque control methods based on both speed-mode and torque-mode can be used to make response of wind turbine faster. In this paper, two torque control methods based on the traditional torque-mode method are applied to a 2.75 MW wind turbine. It is shown through some simulation results for real turbulence wind speeds that torque control method based on torque-mode has the merit of reducing fluctuations of generated power than PI controller based on speed-mode.