• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.327-330
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• 1996

It is well known that the controller output limits have a signifiant effect on the closed loop system performance. Considering the input constraints in GPCF, an effective selection method of the control weighting(.gamma.) is proposed to reduce the amplitude and the rate of control signals so that control signals lie within the limits. It is based on the relation between control weighting(.gamma.) and optimal solution of the unconstrained GPCF. The GPCFIC algorithm chooses an .gamma. at each sampling time so that all unconstrained GPCF output over the control horizon satisfy the rate and the amplitude constraints. In order to evaluate the performance of the GPCFIC, the computer simulations have been done for level control of PWR steam generator in low power operation and shown satisfactory results.

• Proceedings of the KIPE Conference
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• 2001.12a
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• pp.15-18
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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 and experiments.

• Proceedings of the KIPE Conference
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• 2001.07a
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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.

• Proceedings of the KIPE Conference
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• 2002.07a
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• pp.555-558
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• 2002

The general ways of the anti-islanding can be classified into the active method and passive method. The passive method which use only the voltage information when power failure occurs has much possibility of the wrong detection. And the active method detects the change of the voltage frequency as instantaneously changing the frequency of the inverter output current. Therefore, in this paper, the method to inject arbitrary order harmonics into controlled current is proposed. In this method islanding can be detected by measuring the amount of load voltage of injected harmonics order. And as a current control method predictive control method is used, which make actual current accurately to track reference current by Instantaneously computing converter output voltage and has fast response in transient state. This parer proposed method was verified by simulation.

• Korean Chemical Engineering Research
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• v.52 no.5
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• pp.592-602
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• 2014

In the Integrated Gasification Combined Cycle (IGCC), the stability of the gasifier has strong influences on the rest of the plant as it supplies the feed to the rest of the power generation system. In order to ensure a safe and stable operation of the entrained-flow gasifier and for protection of the gasifier wall from the high internal temperature, the solid slag layer thickness should be regulated tightly but its control is hampered by the lack of on-line measurement for it. In this study, a previously published dynamic simulation model of a Shell-type gasifier is reproduced and two different linear model predictive control strategies are simulated and compared for multivariable control of the entrained-flow gasifier. The first approach is to control a measured secondary variable as a surrogate to the unmeasured slag thickness. The control results of this approach depended strongly on the unmeasured disturbance type. In other words, the slag thickness could not be controlled tightly for a certain type of unmeasured disturbance. The second approach is to estimate the unmeasured slag thickness through the Kalman filter and to use the estimate to predict and control the slag thickness directly. Using the second approach, the slag thickness could be controlled well regardless of the type of unmeasured disturbances.

• Journal of the Korean Society for Precision Engineering
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• v.33 no.5
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• pp.401-407
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• 2016

This paper describes the derivation methodology of the working torque predictive model that can be used in the initial design stages of the impact hammer tool. The working torque control mechanism is designed, taking into account various factors, such as the force of the spring and friction. Firstly, the analysis dynamic model for working environments was modeled as an additional bush and spring, and verified by comparing the test results of the working torque. Secondly, the main performance parameters of the working torque were theoretically defined by analyzing the operating mechanism. The equation to predict the working torque was derived using the dynamic analysis results according to the value changes of the parameters. The prediction equation of the working torque was validated by comparing the predicted results with the experimental data. The error difference between the experimental data and the predictive model results was found to be 8.62%.

• Proceedings of the KIPE Conference
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• 2018.07a
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• pp.296-297
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• 2018

본 논문은 3상 T-type 3-레벨 인버터의 모델예측제어에 관한 연구이다. 모델예측제어는 시스템의 모델링을 통한 최적의 성능을 제공하는 제어기법으로 PI 제어보다 빠른 동특성을 갖지만, 정확한 파라미터 값이 요구된다. 본 논문에서는 시스템 파라미터 오차가 3상 T-type 3-레벨 인버터의 예측제어에서 어떤 영향을 주는지 알아보고 출력 파형을 분석한다.

• Proceedings of the KIPE Conference
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• 2015.07a
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• pp.520-521
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• 2015

본 논문은 벡터제어 기반의 IPMSM 구동 시스템에서 순시 토크 제어 시 전류제어기법에 따른 스위치의 온도특성에 관하여 기술하였다. 전류제어 기법으로는 예측전류제어기법과 기존의 PI(Proportional Integral) 제어기 기반의 SVPWM을 각각 적용하였고, 순시 토크 제어에 따른 스위치 발열량을 비교 분석하였다.

• Proceedings of the KIEE Conference
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• 1993.07b
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• pp.818-820
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• 1993

In the three phase full-wave thyristor rectifier, heat radiation concentrated at a few thyristor(s), while equipment's output is normal. That is very important on the predictive maintenance or checking including replacement of parts(or modules). Therefore, this report explains the method of effective diagnosis and the reason that firing control modules have to be adjusted accuratly on each phase.

• Proceedings of the KIPE Conference
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• 2015.11a
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• pp.145-146
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• 2015

본 논문은 3상 T-type 3-레벨 인버터의 중성점 전압 제어를 위한 예측제어에 관한 연구이다. 최근 인버터의 효율 향상 등의 장점으로 멀티레벨 인버터가 주목받고 있다. 모델예측제어 방식은 물리적 입력 상태를 반영하여 최적의 성능을 제공할 수 있는 제어기법이다. 3-레벨 인버터에서는 전압벡터의 개수가 많아 예측제어기법을 적용하기에는 계산시간이 오래걸리는 단점이 있다. 본 논문에서는 SPWM 방식에 예측저어를 통해 offset 을 주는 방식으로 DC-link단 중성점 전압제어를 하였다.