• 전력전자학회:학술대회논문집
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• 전력전자학회 2007년도 하계학술대회 논문집
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• pp.16-18
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• 2007

In this paper, an advanced DTC(Direct Torque Control) scheme for PMSM(Permanent Magnet Synchronous Motor) is presented. The proposed DTC method uses a conventional torque estimator and torque error. But the switching signal is generated by PWM method according to the switching rules and torque error. A simple calculation of PMW without any complex determination of space vector can assure the constant switching frequency with an excellent control performance. The proposed torque control scheme for PMSM is verified by computer simulation.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 B
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• pp.1208-1210
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• 2003

Most of all, DTC drive is very simple in its implementation because it needs only two hysteresis comparator and switching vector table for both flux and torque control. The amplitude of hysteresis band greatly influences on the drive performance such as flux and torque ripple and inverter switching frequency. In this paper the influence of the amplitudes of flux and torque hysteresis bands and sampling time of control program on the torque and flux ripples are investigated. Simulation results confirm the superiority of the DTC under the proposed method over the conventional DTC.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 추계학술대회 논문집 학회본부 B
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• pp.336-338
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• 2000

Recently many studies have been performed for variable speed control of induction motor. Direct Torque Control(DTC) is emerging technique for variable speed control of PWM inverter driven induction motor. DTC allows the direct control of stator flux and instantaneous torque through simple algorithm. In this paper ASIC design technique using VHDL is applied to DTC based speed control of induction motor. ASIC for DTC based speed control is designed through the description of coordinate transformation, speed controller stator flux and torque estimator, stator flux and torque controller, stator flux position detector. FSM(Finite State Machine) and inverter voltage switching vector. Finally the above system has been implemented on the FPGA (XC4052XL-PG411). Simulation and experiment has been performed to verify the performance of the designed ASTC.

• 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.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2001년도 전력전자학술대회 논문집
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• pp.426-429
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• 2001

This paper describes a control scheme for direct torque and flux control of induction machines. The proposed predictive flux control scheme has directly calculated the reference voltage space vector based on flux errors in order to control the torque and flux. This proposed control scheme has not the requirement of a separate current regulator and proportional-integral (PI) control of the flux, torque, and/or current error, thereby improving transient performance and also has the advantage of less torque ripple in steady state with a fixed switching period. The effect of proposed method has been proven by simulations.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2001년도 전력전자학술대회 논문집
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• pp.25-29
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• 2001

The BLDCM (Brushless DC Motor) characterized by linear torque to current, and speed to voltage has low acoustic noise, and fast dynamic response. Moreover, it has high power density with high proportion of torque to inertia in spite of small size drive. But, it produce torque ripple due to the motor inductance components in stator windings and back-EMF, when armature current is commutated. Therefore, it is difficult to apply the BLDCM to a precision servo drive system. In this paper is proposed to a new current control algorithm with using fourier series coefficients can minimize torque ripple due to the phase current commutation of BLDCM. Simulation and Experimental results prove the effectiveness the proposed algorithm through comparison with the conventional used unipolar PWM method.

• 전기학회논문지
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• 제63권10호
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• pp.1384-1392
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• 2014

This paper presents a torque ripple reduction algorithm for the switched reluctance motor drives using the fuzzy logic and the sliding mode control. A turn-on angle controller based on the fuzzy logic determines the optimal turn-on angle. In addition, a sliding mode torque control (SMTC) methods reduces torque ripples instantaneously in the commutation region. The proposed algorithm does not require complex system models considering nonlinear magnetizing or demagnetizing periods of the phase current. According to the rotor speed and torque, the proposed controller changes the turn-on angle and reference torque instantaneously until the torque ripples are minimized. The simulation and experimental results verify the validity of minimizing the torque ripple performance.

• 조명전기설비학회논문지
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• 제28권7호
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• pp.48-54
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• 2014

This paper discusses study of torque ripple minimization employing an improved TDF(torque distribution function)-based instantaneous torque control to reduce acoustic noise and vibration problem of the SRM. As the flux linkage of the SRM is a nonlinear function of phase current and rotor position, design of optimal controller for the SRM is quite complicated. Hence, an accurate mathematical model considering the nonlinearity of the SRM is required. An improved TDF based torque control has been proposed in order to reduce the toque ripple at high speed operation. Dynamic simulation using Matlab/Simulink as well as Finite Element Analysis is presented. A prototype SRM for electric vehicle traction has been manufactured to validate the experimental results comparing the dynamic simulation results.

• 한국군사과학기술학회지
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• 제2권2호
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• pp.242-250
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• 1999

This paper presents an estimation scheme of the external torque applied on the motor by using measured motor input current when the IPM(Interior Permanent Magnet) rotor type BLDC motor operates with constant speed. In general, the BLDC motor is controlled by vector control method. If it could be operated at over critical speed, the control scheme must be modified to flux-weakening control method. The external torque applied on the motor using flux-weakening control method could not be calculated by conventional torque equation because the demagnetizing current Id exists in the motor input current. In this paper, the commonly used flux-weakening control method is studied and the modified torque estimation scheme is suggested. The estimation scheme has been verified by the simulations and experimental results.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2008년도 추계학술대회 논문집
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• pp.22-24
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• 2008

영구자석 동기전동기(Permanent Magnet Synchronous Motor)를 벡터 제어로 구동 시 정확한 회전자 위치정보가 요구된다. 일반적으로 레졸버(Resolver)를 이용하면 회전자의 절대 위치(absolute position)를 알 수 있다. 하지만 레졸버의 변압비 차이, 불평형 여자신호, 불균일한 인덕턴스 성분, 신호처리 회로상의 왜곡으로 인해 신호의 크기 불평형이 발생하고 이는 위치정보에 주기적인 오차 성분이 나타나게 되며, 이러한 오차 성분들은 토크에 영향을 준다. 본 논문에서는 이러한 오차 성분을 수학적 해석을 바탕으로 확인하고 보상하는 방법을 제안하였다. 제안된 알고리즘의 타당성을 실험을 통해 검증하였다.