• Title, Summary, Keyword: Motor Point

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Vector Control of Induction Motors using Optimal Efficiency Control

  • Kim, Sang-uk;Chi, Jin-ho;Kim, Young-seok
    • Journal of Power Electronics
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    • v.2 no.1
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    • pp.67-75
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    • 2002
  • This paper presents the control algorithm for maximum efficiency drives of an induction motor system with the high dynamic performance. This system uses a simple model of the induction motor that includes equations of the iron losses. The model, which only requires the parameters of the induction motor, is referred to a field-oriented frame. The minimum point of the input power can be obtained at the steady state condition. The proposed optimal efficiency control algorithm calculates the reference torque and flux currents for the vector control of the induction motors. A 32 bit floating point TMS320C32 DSP chip implements the drive system with the efficiency optimization controller. The results show the effectiveness of the control strategy Proposed for the induction motor drive.

Precision Control X-Y Table Using Dual Modulus Technique

  • Choi, Gi-Sang;Unhavanich, SumaLee
    • 제어로봇시스템학회:학술대회논문집
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    • pp.82.6-82
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    • 2001
  • This paper presents the control X-Y table being the precise movement by point-to-point in the x-y plane. The dual modulus technique is used for our system to control the frequency of pulse supplied to the motors. Such technique is used to stop motor of both axes accurately as the desired target point in the same period. Both motors are stepping motor. To Improve steps per revolution, we employ ministep form to drive motors. In system, personal computer, using parallel port, is used for computing algorithm in open-loop form to control motors. In experiment, our system applies on the X-Y table for drawing to test system performance.

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A Clinical Application with the Principle of Hanging Point In the Sling Exercise Therapy (슬링운동치료에서 Hanging Point의 원리와 임상적 적용)

  • Kim, Suhn-Yeop;Kim, Taek-Yean;Park, Sung-Jin
    • The Journal of Korean of Orthopedic Manual Physical Therapy
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    • v.9 no.2
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    • pp.25-45
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    • 2003
  • Sling exercise treatment(S-E-T) is a therapeutic exercise based on scientific studies for the purpose of treating musculoskeletal or neurological disorders thereby improving strength, endurance, and skills for sensory-motor integration. Exercise resistance and intensity can be modified in various ways by changing the length of rope, patient position, therapist's manual resistance, and using elastic rope. The therapist can also progress to successively higher levels of exercise resistance and intensity by changing the position of the hanging point: the subject of this article. In brief, there are three axial components in S-E-T; hanging point, motor axis, and suspension point. The hanging point can be changed in several ways in relation to the joint; axial, superior, inferior, medial, and posterior hanging points. The position of the hanging point affects the amount of load on agonist and antagonist muscles as well as on the range of motion. To create an advanced exercise program, selection of hanging point can be two-dimensional such as superior-lateral or anterior-medial. Therapists, therefore, can freely but carefully select the best hanging point based on the purpose of the exercise and their level of knowledge in S-E-T.

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System-level Analysis of a Fan-motor Assembly for Vacuum Cleaner (진공청소기용 팬-모터 어셈블리의 시스템-레벨 분석)

  • Park, Chang-Hwan;Park, Kyung-Hyun;Chang, Kyung-Sik
    • The KSFM Journal of Fluid Machinery
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    • v.20 no.1
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    • pp.5-14
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    • 2017
  • A fan-motor assembly in a vacuum cleaner is analyzed through system-level analysis method. This system consisted of three components, a fan, motor, and the flow resistance of the motor, or of the vacuum cleaner. System-level analysis method is characterized by the combination of torque matching at a constant throttling condition between the fan and the motor and the pressure drop at a constant flow rate due to the flow resistance of the motor, or of the vacuum cleaner. The performance characteristics of the fan-motor assembly and the vacuum cleaner system could be predicted over the whole range of operation, based on the characteristics of each component. The predicted performance of the vacuum cleaner system through system-level analysis agreed well with the experimental results within 4.5% difference of pressure and 6% difference of the efficiency. The effect of flow resistance of a motor is investigated and it is found that the efficiency decrease of fan-motor assembly at the constant flow rate due to the flow resistance of a motor is determined by the flow resistance ratio(FRR), which is defined as a ratio of flow resistance of motor and the flow resistance of a constant throttling condition of a given point. The fan-motor assembly(S2 model) was modified to reduce the FRR from 9.0% to 2.4% and the experimental result shows that the efficiency of S2 model was improved by about 3% at best efficiency point.

High Resolution Position Control of Linear Permanent Magnet Synchronous Motor for SMD Placement System (SMD Mounter용 선형 영구자석 동기기의 고정밀 위치제어)

  • Kim, Jang-Hwan;Sul, Seung-Ki;Jeon, Jeong-Yul;Choi, Yun-Kyu
    • Proceedings of the KIEE Conference
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    • pp.314-316
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    • 2001
  • This paper present the position control method for the application of permanent magnet linear synchronous motor. Controller is designed as a conventional P-PI controller, but the extra information is used such as velocity and acceleration from motion profiles. The profiles comes from S-Curve which is an optimized point-to-point motion profiles to achieve fast motions with minimum vibration[2]. In this application, the targets of the position control are maximum 10um position error within 10msec after respective ending point of position profiles. The implementation of the controller has been done in full digital way. All the controller is designed on the DSP TMS320VC33 control board. To prove performance of the controller, the experiment was performed with a servo linear motor.

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A Study on the Influence of Commutation Time on Torque Pulsating in BLDCM (BLDC 모터에서 전류시간이 토크맥동에 미치는 영향에 관한 연구)

  • Kim, Cheol-Ju;Gang, Byeong-Hui;Mok, Hyeong-Su;Choe, Gyu-Ha
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.50 no.1
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    • pp.23-29
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    • 2001
  • A BLDC motor has a serious drawback that torque pulsation is generated in every commutation period though it has many advatages compared to the conventional DC Motor. In this paper, the influence of commutation time on torque pulsation is studied. Generally in calculating the torque of BLDC motor, it is assumed that the decaying phase back EMF is constant, but the torque model considering decaying phase back EMF is introduced here. Through it, the torque in commutation period has torque pulsation component caused by commutation itself and it cannot be removed perfectly even if there is no current pulsation. To reduce the torque pulsation, a new method is proposed, which controls a point of commutation and the optimal point of commutation is found. Simulation shows that proposed method reduces the torque pulsation considerately.

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A Study on Optimal Current Control Method for Small BLDC Motor Drive (소형 BLDCM 드라이브의 최적 전류제어에 관한 연구)

  • Park, Chang-Seok;Jung, Tae-Uk
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.29 no.4
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    • pp.108-115
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    • 2015
  • This paper proposed a optimal current control method to improve efficiency of BLDC motors. The aim of the proposed method is to use the maximum torque operating method by increasing the effective voltage at the maximum torque point unlike existing SPM operating method. The proposed method is based on existing IPM maximum torque operating method grafting onto a square wave operating of SPM motors. As the method of increasing the effective output voltage from inverter using the maximum torque point, the proposed method is to improve efficiency of BLDC motors using the same amount of the existing current effectively. For this method, the maximum torque point is carried out by FEA and analysis of magnetic flux vector. In this paper, the prototype of general-purpose BLDC drive is manufactured and the performance characteristic and validity are verified.

Analysis About How Human Foot Move During Driving Condition (중형승용차 운전 중 발거동 분석)

  • Park, Bo-Hyun;Jung, Hee-Seok;Lee, Sung-Hwan
    • Journal of Korean Institute of Industrial Engineers
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    • v.38 no.1
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    • pp.41-45
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    • 2012
  • Until now, most studies of foot moving or driving posture have been performed under laboratory driving conditions. But there are many different things between actual driving conditions and laboratory driving conditions because, in laboratory conditions, it is hard to consider vehicle's noise, vibration and people's psychology state while driving. Thus this study is performed through actual driving conditions. And while driving test, we recorded driver's foots with 2 cameras to investigate foots(left and right) heel point and how human foots move to control the three pedals : accel, brake and footrest.. Through driving test, the results of this study show that the position of driver's heel point isn't related to stature and tends to be generalized.

Torque Ripple Reduction in Three-Level Inverter-Fed Permanent Magnet Synchronous Motor Drives by Duty-Cycle Direct Torque Control Using an Evaluation Table

  • Chen, Wei;Zhao, Ying-Ying;Zhou, Zhan-Qing;Yan, Yan;Xia, Chang-Liang
    • Journal of Power Electronics
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    • v.17 no.2
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    • pp.368-379
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    • 2017
  • In this paper, a direct torque control algorithm with novel duty cycle-based modulation is proposed for permanent magnet synchronous motor drives fed by neutral-point clamped three-level inverters. Compared with the standard DTC, the proposed algorithm can suppress steady-state torque ripples as well as ensure neutral-point potential balance and smooth vector switching. A unified torque/flux evaluation table with multiple voltage vectors and precise control levels is established and used in this method. This table can be used to evaluate the effects of duty-cycle vectors on torque and flux directly, and the elements of the table are independent of the motor parameters. Consequently, a high number of appropriate voltage vectors and their corresponding duty cycles can be selected as candidate vectors to reduce torque ripples by looking up the table. Furthermore, small vectors are incorporated into the table to ensure the neutral-point potential balance with the numerous candidate vectors. The feasibility and effectiveness of the proposed algorithm are verified by both simulations and experiments.

Experimental Test for the Optimum Design of a Rotor Slot in Three Phase Inverter-fed Induction Motor (3상 인버터 구동 유도전동기의 회전자 1 슬롯 최적설계에 관한 실험)

  • Kim, J.W.;Kwon, B.I.;Kim, B.T.;Jo, Y.
    • Proceedings of the KIEE Conference
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    • pp.131-134
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    • 2002
  • The optimum design technology using combind F.E.M and eauivalent circuit is so fast and accurate that it can be applied to the optimum rotor design of an inverter-fed induction motor in high efficiency motor making industry. The optimum characteristics fer a rotor slot model of a 3 phase inverter-134 nduction motor was previously verified by a time-step F.E.M. In this paper, four verification models with the design variables near the optimum point are designed to chech whether the characteristics of a slot model presented is not less than those of the near models. The outputs of whole models are analyzed in a time-step Finite Element Method and compared in the experimental test. The economical and efficient selecting method of design variables fur the computer simulation and experimental test is presented in order to assure the optimum point.

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