• 전기전자학회논문지
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• 제24권4호
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• pp.1104-1108
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• 2020

본 논문에서는 3상 영구자석 동기전동기의 속도리플 저감을 위한 가변형 비례공진 전향보상 알고리즘을 제안한다. 일반적인 토크 맥동의 원인은 전류측정오차 및 데드타임으로 인한 전기적 맥동과 회전자 편심과 편심 부하로 인해 발생될 수 있다. 이러한 토크 맥동은 전동기의 속도 맥동을 야기하고 전동기 구동 시스템의 운전 성능을 저하시킬 수 있다. 이를 위한 본 논문에서는 속도 맥동의 원인을 분석하고 속도 맥동을 저감하기 위한 알고리즘을 제안하였다. 제안한 알고리즘은 속도 맥동에 포함된 특정 운전 주파수를 저감하기 위해 가변형 비례 공진 제어기를 적용하였고, 전향보상 제어기 구조를 이용하여 보상동작이 수행되도록 하였다. 제안한 알고리즘은 다양한 실험을 통하여 타당성과 효용성을 검증하였다.

• 전기학회논문지
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• 제67권9호
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• pp.1165-1173
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• 2018

Recently, owing to environmental problems and instability of rare earth resources market, non-rare earth electric motors are attracting attention. As a non-rare earth motor type, a wound rotor synchronous motor(WRSM) has high power density and wide driving range further it can reduce loss by field current control during field weakening control at high speed. However, since the d-axis flux of the WRSM is coupled with the rotor circuit, the fluctuation in the d-axis flux linkage affects the rotor circuit, which causes ripple of the field current and torque. In this paper, we propose the field current ripple compensation method by injecting the feedforward voltage. the proposed compensating method was demonstrated by simulation and experiments.

• Journal of Power Electronics
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• 제17권3호
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• pp.716-724
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• 2017

The output voltage of an off-grid inverter is influenced by load current, and the voltage harmonics especially the 5th and 7th are increased with nonlinear loads. In this paper, to attenuate the output voltage harmonics of off-grid inverters with nonlinear loads nearby, a load current feedforward is proposed. It is introduced to a voltage control loop based on the Positive and Negative Sequence Harmonic Regulator (PNSHR) compensation to modify the output impedance at selective frequencies. The parameters of the PNSHR are revised with the output impedance of the off-grid inverter, which minimizes the output impedance of the off-grid inverter. Experimental results verify the proposed method, showing that the output voltage harmonics caused by nonlinear loads can be effectively suppressed.

• 한국소음진동공학회논문집
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• 제15권11호
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• pp.1303-1310
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• 2005

Stabilization error of target aiming systems mounted on moving vehicles is an important performance because the error directly affects hit Probability. In a heavy load targetaiming system, the disturbance torque comes from mass unbalance and linear acceleration is a main source of stabilization error. This study suggests an experimental design method of disturbance feedforward compensation control to improve the stabilization performance of heavy load target aiming systems. The filtered_x least square(FxLMS) algorithm is used to estimate the compensator coefficients adaptively. The proposed control is applied to a simple experimental set-up which simulates dynamic characteristics of a real target aiming system. The feasibility of the proposedtechnique is illustrated, along with results of experiments.

• 한국정밀공학회지
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• 제15권8호
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• pp.145-155
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• 1998

An $H{\infty}$ controller with a roll eccentricity filter is proposed to alleviate the effect of entry thickness variation and roll eccentricity occured in rolling stands themselves of tandem cold mills. A robust controller to the disturbances is designed by H$_{\infty}$ control techniques, which can reflect the input direction of disturbances and the knowledge of disturbance spectrum in the frequency domain. First, fundamental problems in tandem cold mills such as process transport delay inherent in the exit thickness measurement and the feedforward loading of roll eccentricity signals on the exit thickness be overcome by the roll eccentricity filtering and the compensation for the error of gaugemeter thickness estimator. And non-satndard $H{\infty}$ control problem caused by the selection of weighting function having poles on the $J{\omega}$-axis is discussed. The resultant controller composed by an $H{\infty}$ controller and an estimator for the roll eccentricity is evaluated through computer simulations. The effectiveness of the proposed control method is compared to that of the conventional LQ controller method and a feedforward controller for the roll eccentricity, which has been already studied.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2003년도 춘계전력전자학술대회 논문집(2)
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• pp.663-666
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• 2003

This paper presents a speed controller method based on the disturbance torque observer of high performance brushless DC (BLDC) motor drives. In case of the speed control of robot arms and tracking applications with lower stiffness, we cannot design the speed controller gain to be very large from tile viewpoint of the system stability. Thus, the feedforward compensator using disturbance torque observer was proposed. This method can improve the speed characteristic without increasing the speed controller gain. The enhanced speed control performance can be achieved and the speed response against the disturbance torque can be Improved for high-performance BLDC motor drive systems in which the bandwidth of tile speed controller cannot be made large enough. Consequently, speed control for high-performance BLDC motor drives become improved. The simulation results for BLDC motor drive systems confirm the validity of the proposed method.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.2582-2587
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• 2003

This paper proposes an application of sliding mode observer to the problem of fault detection and reconstruction for descriptor systems with both actuator and sensor faults. In detecting and reconstructing the faults simultaneously, first, we will consider the fault detection problem for sensor fault. The detection of sensor fault is achieved from the design of the matrix which eliminates the influence of actuator fault. Secondly, the sliding mode observer which adds the general full-order observer for descriptor system to feedforward injection map and feedforward compensation signal is designed, and through which the sensor fault is reconstructed. Finally, with the reconstructed sensor fault, and by eliminating differential term of the sensor fault, the actuator fault is detected and reconstructed.

• 한국항행학회논문지
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• 제13권5호
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• pp.756-762
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• 2009

비선형 마찰인 유압 작동기의 스틱-슬립 마찰은 정확성과 응답성에 문제가 된다. 그러므로 마찰보상은 다양한 제어알고리즘을 통하여 연구되어 왔다. 적응이산시간 슬라이딩 추종제어기는 유압작동기 내의 비선형 마찰 특성을 보상하기 위하여 적용하였다. 다오판틴 방정식을 기초로 하여 새로운 이산시간 슬라이딩 함수는 마찰과 모델링 오차를 포함하여 제어법칙을 정의하였다. 비선형 파라미터의 추종성을 기초로 슬라이딩 함수와 프로젝션 항수를 이용하여 강인성을 높였다. 시뮬레이션과 실험결과는 좋은 추종성능을 얻었다.

• 전기전자학회논문지
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• 제4권2호
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• pp.225-232
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• 2000

전압원 인버터의 PWM 신호에 삽입되는 데드 타임은 인버터 출력 파형을 왜곡시키고, 토크 리플을 발생시켜 유도 전동기의 제어 성능을 떨어뜨린다. 본 논문에서 벡터 제어 유도 전동기의 데드 타임 보상 방법이 제안된다. 제안된 방법은 2상 정지 좌표계에서 인버터 출력 기준전압에 보상 전압을 더하는 전향 보상에 근거한다. 제안된 방법은 부가적인 하드웨어 없이 소프트웨어적으로 실현 가능하다. 실험 결과를 통하여 제안된 방법의 타당성과 유용성을 확인한다.

• 한국자동차공학회논문집
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• 제4권6호
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• pp.196-204
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• 1996

The simplified dynamic models of the timer assembly in the diesel engine fuel injection system were developed. The first order system with time delay was assumed and the various parameters in this model were obtained by experimental data. These simplified dynamic models were used for the development of control algorithm of the injection timing control system. The PI control algorithm was modified to include the anti-windup property and disturbance compensation. This modified PI control algorithm was used for the control of the injection timing. Improved control accuracy and reduced control efforts were observed.