• 제목/요약/키워드: torque characteristics

검색결과 1,773건 처리시간 0.037초

Influence of Cogging Torque Reduction Method on Torque Ripple in a Surface-Mounted Permanent Magnet Synchronous Motor

  • Kim, Tae-Woo;Chang, Jung-Hwan
    • Journal of Magnetics
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    • 제17권2호
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    • pp.109-114
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    • 2012
  • The torque characteristics of a surface-mounted permanent magnet synchronous motor (SPMSM) are analyzed in this study. The harmonics of the back electromotive force (EMF) and cogging torque are analyzed by the finite element method to study their effects on the torque ripple. Although low cogging torque can be achieved by varying geometric parameters such as the permanent magnet (PM) offset and notch depth on the stator teeth, the torque ripple is increased in some cases. The analysis results show that the ripple of the generated torque is determined by not only the amplitudes but also the phases of harmonics for the back EMF and cogging torque.

토오크 기울기 및 기준전압제어에 의한 유도전동기의 직접토오크 제어 (Direct Torque Control of Induction Motor by Torque Slope and Reference Voltage Control)

  • 김평호;최연옥;조금배;백형래;이상일
    • 대한전기학회논문지:전기기기및에너지변환시스템부문B
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    • 제55권1호
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    • pp.9-15
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    • 2006
  • The conventional hysterysis band DTC(Direct Torque Control) strategy have relatively high torque ripple at low speed and variable switching frequency according to motor speed even though it provides a fast torque response with very simple scheme consisted with only two hysteresis band comparators and a switching table for torque and flux control. In this paper, author proposed a new DTC scheme based on the torque slope and reference voltage control. The new scheme can maintain the minimized torque ripple and constant switching frequency. Experimental tests carried out with an 1.5kW induction motor drive system show improved dynamic characteristics and prove the feasibility of proposed strategy.

Modified Direct Torque Control System of Five Phase Induction Motor

  • Kim, Nam-Hun;Kim, Min-Huei
    • Journal of Electrical Engineering and Technology
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    • 제4권2호
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    • pp.266-271
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    • 2009
  • In this paper, improved direct torque control(DTC) of five-phase induction motor(IM) is proposed. Due to the additional degrees of freedom, five-phase IM drives present unique characteristics. One of them is the ability of enhancing the torque producing capability of the motor. Also five-phase motor drives possess many others advantage compared with the traditional three-phase motor drives. Such as, reducing the amplitude and increasing of frequency of torque pulsation, reducing amplitude of current per phase without increasing the voltage per phase and increasing the reliability. The direct torque control method is advantageous when it is applied to the five-phase IM. Because the five-phase inverter provides 32 space vectors in comparison to 8 space voltage vectors by the three-phase inverter. The 32 space voltage vectors are divided into three groups according to their magnitudes. The characteristics and dynamic performance of traditional five-phase DTC are analyzed and new DTC for five-phase IM is proposed. Therefore, a more precise flux and torque control algorithm for the five-phase IM drives can be suggested and explained. For presenting the superior performance of the pro-posed direct torque control, experimental results is presented using a 32 bit fixed point TMS320F2812 digital signal processor

자기기동 및 토크리플 저감을 위한 12/14 베어링리스 SRM의 설계 및 특성해석 (Analysis and Design of 12/14 Bearingless Switched Reluctance Motor for Self-Starting and Torque Ripple Reduction)

  • 서진요;이동희;안영주;안진우
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2015년도 제46회 하계학술대회
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    • pp.682-684
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    • 2015
  • A 12/14 bearingless switched reluctance motor (BLSRM) with hybrid stator poles has been proposed due to the outstanding decoupling characteristics between the torque and suspending force. However, the motor is a two-phase motor. The output torque of the motor has torque dead zone and high torque ripple. Hence, the motor cannot self-start at some rotor positions. To solve the self-starting problems and reduce the torque ripple, a stepped rotor is proposed in this paper. Then, the motor with the stepped rotor is optimally designed. In the new designed motor, the majority parameters are kept the same with those of original motor; only the torque pole arc and rotor pole shape are optimally designed. The characteristics of the redesigned motor, such as inductance, torque and suspending force, are analyzed and compared with those in the original motor. Finally, the effectiveness of the proposed method is verified by the simulation results.

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Loss of Torque on Magnetic Fluid Seals with Rotating-shafts

  • Hu, Jianhui;Zhao, Meng;Wang, Lu;Zou, Jibin;Li, Yong
    • Journal of Magnetics
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    • 제22권2호
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    • pp.286-290
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    • 2017
  • The effects of loss of torque on magnetic fluid seals with rotating-shafts and the general difficulty of studying magnetic fluid seals are the focus of this work. The mechanism underlying loss of torque on such seals is analyzed using theoretical methods that show that loss of torque can be affected by several factors, including the velocity of the rotating-shaft, the structure of the sealing device, the characteristics of the magnetic field, and the characteristics of the magnetic fluid. In this paper, a model of the loss of torque is established, and the results of finite element analysis and testing and simulations are analyzed. It is concluded that (i) the viscosity of the magnetic fluid increased with the intensity of the magnetic field within a certain range; (ii) when the magnetic fluid was saturated, the increase in loss of torque tended to gradually slow down; and (iii) although the axial active length of the magnetic fluid may decrease with increasing speed of the rotating-shaft, the loss of torque increased because of increasing friction.

토크와 전류 평면에서 최대토크 운전을 위한 IPMSM의 순시 토크제어 (Instantaneous Torque Control of IPMSM for maximum Torque Drive in Torque and Current Plane)

  • 이홍균;이정철;정동화
    • 전기학회논문지P
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    • 제52권1호
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    • pp.1-8
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    • 2003
  • The paper proposes instantaneous torque control of IPMSM for maximum torque drive of torque and current plane. The control scheme is based on the mathematical model of the motor and is applicable to the constant torque and field weakening operations. The scheme allows the motor to be driven with maximum torque per ampere(MTPA) characteristic below base speed and it maintains the maximum voltage limit of the motor wide field weakening and the motor current limit under all conditions of operation accurately. For each control mode, a condition that determines the optimal d-axis current $^id$ for maximum torque operation is derived. The proposed control algorithm is applied to IPMSM drive system for drive of wide speed range, the operating characteristics controlled that maximum torque control are examined in detail by simulation.

더블 베인 회전형 유압 구동시스템의 임피던스 제어를 위한 토크 서보 설계 (Design of Torque Servo for Impedance Control of Double Vane Rotary Hydraulic Actuator System)

  • 김선민;최영진;정완균
    • 로봇학회논문지
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    • 제5권2호
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    • pp.160-168
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    • 2010
  • In order to achieve a force controller with high performance, an accurate torque servo is required. However, the precise torque servo for a double vane rotary actuator system has not been developed till now, due to many nonlinear characteristics and system parameter variations. In this paper, the torque servo structure for the double vane rotary actuator system is proposed based on the torque model. Nonlinear equations are set up using dynamics of the double vane rotary hydraulic actuator system. Then, to derive the torque model, the nonlinear equations are linearized using a taylor series expansion. Both effectiveness and performance of the design of torque servo are verified by torque servo experiments and applying the suggested torque model to an impedance controller.

자동차용 토크 컨버터의 수치해석적 연구(Part II) -날개각과 성능- (A Numerical Study on the Automotive Torque Converter(Part II) -Blade Angles and Performances-)

  • 박재인;조강래
    • 한국자동차공학회논문집
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    • 제6권6호
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    • pp.174-184
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    • 1998
  • The situation frequently occurs in which the input torque capacity of the torque converter should be changed. It is known that the modification of the outlet blade angles of the torque converter elements is suitable for such situation with the outer diameter of flow path of the converter maintained. But so far it has been difficult to predict correctly the converter characteristics as well as the effect of outlet angles on torque capacity in the past numerical methods. In the present numerical method introducing the interrow mixing planes, the torque capacity was satisfactorily estimated and it was shown that the torque capacity could be effectively changed by modifying the outlet blade angles of pump and stator.

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기동 방법에 따른 단상 SRM의 토크 특성 해석 (The Torque Characteristics Analysis of the Single-Phase Switched Reluctance Motor According to the Starting Method)

  • 김준호;김일중
    • 조명전기설비학회논문지
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    • 제26권9호
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    • pp.40-46
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    • 2012
  • The single-phase switched reluctance motor(SRM) has only one inductance variation and the positive torque is generated in the restricted section. So, it cannot be started by itself. To solve this problem, many researchers have addressed the several starting method for the single-phase SRM. This paper is focused on the torque characteristics of the single-phase SRM according to starting method. The four major starting method - permanent magnet, saturable stator pole, to grade the rotor, stepped rotor pole - is selected to analyze the torque characteristics. The analysis model of each starting method is designed to changed the pole shape or inserting other material in the basic model. The torque characteristics of each analysis model is obtained by using FEM analysis. The FEM analysis is performed at incremental rotor positions over half inductance cycle in any one pole with 250AT, 500AT, 750AT. The distortion factor of each analysis model is analyzed through the FFT to compare the distortion between basic model and four analysis model.

볼스크류로 구동되는 유정압테이블의 미소이송특성 향상 (Improvement of Microstep Characteristics in Hydrostatic Table with Ballscrew)

  • 황주호;박천홍;이찬홍;이후상
    • 한국정밀공학회지
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    • 제15권1호
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    • pp.94-100
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    • 1998
  • Microstep characteristics largely depends on the variation of friction force induced by the geometric accuracy of ballscrew, guide rail and the control characteristics of servo unit. In this paper, for improving the microstep characteristics of hydrostatic table with ballscrew, microstep resolution according to the control mode of servo amplifier and response characteristic by the variation of integral gain are tested and compared. Relationship between micro motion behavior of hydrostatic table and the output torque is also tested for acquiring the effective variables on control characteristics. From the results. it is confirmed that the torque control mode has a advantage in microstep resolution, and more stable than velocity control mode in low feed rate, and by the increase of integral gain in the elastic motion realm, response characteristics can be improved.

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