• Journal of Power Electronics
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• 제12권5호
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• pp.787-799
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• 2012

Real and reactive power flows on a transmission line interact inherently. This situation degrades power flow controller performance when independent real and reactive power flow regulation is required. In this study, a quasi multi-pulse interline power flow controller (IPFC), consisting of eight six-pulse voltage source converters (VSC) switched at the fundamental frequency is proposed to control real and reactive power flows dynamically on a transmission line in response to a sequence of set-point changes formed by unit-step reference values. It is shown that the proposed hybrid fuzzy-PI commanded IPFC shows better decoupling performance than the parameter optimized PI controllers with analytically calculated feed-forward gains for decoupling. Comparative simulation studies are carried out on a 4-machine 4-bus test power system through a number of case studies. While only the fuzzy inference of the proposed control scheme has been modeled in MATLAB, the power system, converter power circuit, control and calculation blocks have been simulated in PSCAD/EMTDC by interfacing these two packages on-line.

• 융합신호처리학회논문지
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• 제3권4호
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• pp.49-56
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• 2002

본 논문에서는 기존의 PDFF 제어기에 비선형 보상기를 적용한 위치제어에 대하여 기술한다. 이 방법은 기존의 방법보다 주어진 사양을 쉽게 만족시킬 수 있다 제어기 설계에 있어서 위상 여유와 대역폭을 동시에 조절할 수 있는 개선된 PDFF 제어기를 제시한다. PDFF 제어기의 전향 보상항을 비선형 보상기(CDIDF 제어기)로 치환함으로서 폐루프시스템의 대역폭을 감소시키지 않으면서 원하는 위상여유를 얻는 것이다. 제시된 방법은 시뮬레이션과 실험을 통하여 확인된다 시뮬레이션 및 실험결과에 따라 CDIDF 제어기를 사용한 개선된 PDFF 시스템에서는 제어기의 파라미터를 적절히 설정함으로서 전반적인 설계사양을 만족시키는 것이 확인된다.

• 조명전기설비학회논문지
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• 제12권4호
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• pp.6-13
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• 1998

본 연구에서는 증기유량, 중기온도 주 급수 온도 및 유량둥과 같은 외란에 의해 증기발생기의 웅축 및 팽창효 과가 발생하여 수위조절에 어려웅이 발생하는 문제를 신경망-PI제어기를 이용해 효과적으로 제어하는 연구를 하였다. 종래의 PI제어기는 저 출력에서 효과적으로 제어 할 수 없어 기동시는 숙련자의 노련한 기술이 필요한데 반해 본 연구에서 적용한 신경망 PI제어기는 Kp,Ti 파라매터를 외란에 영향을 줄 수 있는 파라메터를 고려하여 신경망을 이용해 튜닝함으로서 웅축 및 팽창효과를 줄이고 외란 및 설정치 변경에 대해 효과적으로 제어 될 수 있음을 실험과 시뮬레이션을 통해 확인 할 수 있었다.

• Journal of Power Electronics
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• 제15권4호
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• pp.1066-1073
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• 2015

This paper proposes a control strategy based on the frequency detection method, comprising a current control and a feed-forward voltage control loop, is proposed for grid-interactive power conditioning systems (PCS). For continuous provision of power to critical loads, PCS should be able to check grid outages instantaneously. Hence, proposed in the present paper are a frequency detection method for detecting abnormal grid conditions and a controller, which consists of a current controller and a feedforward voltage controller, for different operation modes. The frequency detection method can detect abnormal grid conditions accurately and quickly. The controller which has current and voltage control loops rapidly helps in load voltage regulation when grid fault occurs by changing reference and control modes. The proposed seamless transfer control strategy is confirmed by experimental results.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2012년도 전력전자학술대회 논문집
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• pp.359-360
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• 2012

This paper proposes a scheme of auto-tuning fuzzy PI controller and input voltage feed forward to control the output voltage of a three-phase Z-source inverter (ZSI). The proposed scheme adjusts the ts (Kp and Ki) in real time in order to find the most suitable Kp and Ki for PI controller and to simplify the controller design. The proposed scheme is verified the validity by experiment and co-simulation in PSIM and MATLAB/SIMULINK both load step change and input DC voltage variation in Z-source inverter, and has compared with the conventional PID control scheme. The experiment results involve of three-phase output voltage, Z-network capacitor voltage and dc-link peak voltage value. By those analysis and comparison, the availability of the proposed method in output voltage transient response quality improving has been verified. Compared with conventional PID method, the proposed method showed a more effective and robust control performance for coping with the severe disturbance conditions.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 추계학술대회논문집
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• pp.387-392
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• 2007

The paper presents control performance of a magnetorheological (MR) fluid-based haptic knob which is applicable to invehicle comfort functions. As a first step, MR fluid-based haptic knob is devised to be capable of both rotary and push motions with a single device. Under consideration of spatial limitation, design parameters are optimally determined to minimize a reciprocal of control torque using finite element analysis. The proposed haptic knob is then manufactured and its fielddependent torque is experimentally evaluated. Subsequently, in-vehicle comfort functions are constructed in virtual environment and make them communicate with the haptic knob. Control performances such as reflection force are experimentally evaluated via simple feed-forward control strategy.

• 한국소음진동공학회논문집
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• 제18권3호
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• pp.307-314
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• 2008

The paper presents control performance of a magnetorheological(MR) fluid-based haptic knob which is applicable to in-vehicle comfort functions. As a first step, MR fluid-based haptic knob is devised to be capable of both rotary and push motions with a single device. Under consideration of spatial limitation, design parameters are optimally determined to minimize a reciprocal of control torque using finite element analysis. The proposed haptic knob is then manufactured and its field-dependent torque is experimentally evaluated. Subsequently, in-vehicle comfort functions are constructed in virtual environment and make them communicate with the haptic knob. Control performances such as reflection force are experimentally evaluated via simple feed-forward control strategy.

• Journal of Electrical Engineering and Technology
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• 제11권2호
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• pp.265-273
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• 2016

A water wall system is one of the most important components of a boiler in a thermal power plant, and it is a nonlinear Multi-Input and Multi-Output (MIMO) system, with 6 inputs and 3 outputs. Three models are developed and comp for the controller design, including a linear model, a multilayer feed-forward neural network (MFNN) model and an Echo State Network (ESN) model. First, the linear model is developed by linearizing a given nonlinear model and is analyzed as a function of the operating point. Second, the MFNN and the ESN are developed by using training data from the nonlinear model. The three models are validated using Matlab with nonlinear input-output data that was not used during training.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 D
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• pp.1941-1942
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• 2006

In this paper new, inverter control system for TG feedback a formula Control was developed. The motor control system with TG feedback controller as an effect of load disturbance, it is very difficult to guarantee the robustness of control system. The function of the implementation are TG feedback type, and temperature scheme. The Inverter Control System approach is based on master-slave control concept. To show validity of the developed new inverter control system, severial experiments are illustrated.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.74.3-74
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• 2001

This paper proposes a nonlinear adaptive controller based on back-stepping method for tracking reference substrate concentration by manipulating dilution rate in a continuous baker´s yeast cultivating process in stirred tank bioreactor. Control law is obtained from Lyapunov control function to ensure asymptotical stability of the system. The Haldane model for the specific growth rate depending on only substrate concentration is used in this paper. Due to the uncertainty of specific growth rate, it has been modified as a function including the unknown parameter with known bounded values. The substrate concentration in the bioreactor and feed line are measured. The deviation from the reference is observed when the external disturbance such as the change of the feed is introduced to the system ...