• Journal of Electrical Engineering and Technology
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• 제10권1호
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• pp.379-387
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• 2015

A custom power device provides an integrated solution to the present problems that are faced by the utilities and power distribution. In this paper, a new controller is designed which is connected to a multiconverter unified power quality conditioner (MC-UPQC) for improving the power quality issues adopted modified synchronous reference frame (MSRF) theory with Fuzzy logic control (FLC) technique. This newly designed controller is connected to a source in order to compensate voltage and current in two feeders. The expanded concept of UPQC is multi converter-UPQC; this system has a two-series voltage source inverter and one shunt voltage source inverter connected back to back. This configuration will helps mitigate any type of voltage / current fluctuations and power factor correction in power distribution network to improve power quality issues. In the proposed system the power can be conveyed from one feeder to another in order to mitigate the voltage sag, swell, interruption and transient response of the system. The control strategies of multi converter- UPQC are designed based on the modified synchronous reference frame theory with fuzzy logic controller. The fast dynamics response of dc link capacitor is achieved with the help of Fuzzy logic controller. Different types of fault conditions are taken and simulated for the analysis and the results are compared with the conventional method. The relevant simulation and compensation performance analysis of the proposed multi converter-UPQC with fuzzy logic controller is performed.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2003년도 춘계전력전자학술대회 논문집(2)
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• pp.503-506
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• 2003

The photovoltaic generators have a nonlinear V-I characteristics and maximum power points which vary with the illumination levels and temperatures. Using maximum power point tracker with the intermediate converter can increase the system efficiency by matching the PV systems to the load. A novel MPPT control for photovoltaic system is proposed. The system input parameters are (dP, dI, and last incremental of duty ratio $L\deltaD$)and the output is the new incremental value (new ${\deltaD}$) according to the maximum power point under various illumination levels. Using fuzzy logic controller allows extracting the maximum power rapidly and without significant oscillations. Also FLC provides excellent features such as fast response, good performance and the ability to change the fuzzy parameters to improve control system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 D
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• pp.2476-2478
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• 2000

Fuzzy Systems which are based on membership functions and rules, can control nonlinear, uncertain, complex systems well. However, Fuzzy logic controller(FLC) has problems: It is some difficult to design the stable FLC for a beginner. Because FLC depends mainly on individual experience. Sliding control is a powerful robust method to control nonlinearities and uncertain parameters systems. But it has a chattering problem by discontinuous control input according to sliding surface. Therfore it needs to be smoothed to achieve an optimal input. In this paper, To solve problems desinged Fuzzy Sliding Control. The effictiveness of result is shown by the simulation and the experimental test for Truck Backer-Upper Control.

• 대한전기학회논문지:시스템및제어부문D
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• 제51권6호
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• pp.252-257
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• 2002

We designed a neuro-fuzzy controller to improve some problems that are happened when the DC servo motor is controlled by a PID controller or a fuzzy logic controller. Our model proposed in this paper has the stable and accurate responses, and shortened settling time. To prove the capability of the neuro-fuzzy controller designed in this paper, the proposed controller is applied to the speed control of DC servo motor. The results showed that the proposed controller did not produce the overshoot, which happens when PID controller is used, and also it did not produce the steady state error when FLC is used. And also, it reduced the settling time about 10%. In addition, we could by aware that our model was only about 60% of the value of current peak of PID controller.

• 한국정보처리학회논문지
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• 제1권3호
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• pp.319-326
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• 1994

자동제어는 그 대상이 근사적 수식화가 가능한 선형시스템에 주로 적용되고 있다. 제어대상에 대한 수학적 모델링이 명확하게 결정되지 않는 경우에는 사람이 직접 제 어하는 수동제어를 하게 된다. 본 논문에서는 수영장과 같이 거의 전적으로 숙력가의 경험에 의존하고 있는 수동제어를 자동제어가 가능하게 FLC(Fuzzy Logic Controller) 를 구축하고, 여기서 사용되는 지식을 가장 최적의 상태로 유지하기 위해 genetic 알고리즘을 사용하여 전문가로부터 얻어온 지식을 개선한다. 또한 규칙부와 소속함수 는 동시에 수정되도록 알고리즘을 설계하여 수동제어보다 제어 성능이 향상됨을 보인 다.

• 한국정보처리학회논문지
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• 제4권1호
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• pp.167-176
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• 1997

교차로에서 통행 패턴의 계속적인 변화와 교통량의 증가 때문에, 매시간 변화에 따라 교차로를 유연성있게 관리할 수 있는 효율적인 교통제어 시스템이 필요하다. 본 논문에서는 교차로를 구성하는 각 도로로 복합성을 자율적으로 분석하여 그 결과에 따라 교차로를 통과할 수 있는 시간을 결정하는 제어 시스템에 관해 연구하였다. 교 통신호 제어를 위해 퍼지 논리 제어기에 퍼지 개념을 적용하였으며, 퍼지 논리 제어 기의 최적 수행을 증명하기 위해서 규칙 신호 시스템을 비교하고 시뮬레이션을 통해 타당성을 증명하였다. 시뮬레이션 결과 교통 제어의 효율성이 6% 정도 향상되었다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 B
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• pp.1079-1082
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• 1996

To automate an excavator the control issues resulting from environmental uncertainties must be solved. In particular the interactions between the excavation tool and the excavation environment are dynamic, unstructured and complex. In addition, operating modes of an excavator depend on working conditions, which makes it difficult to derive the exact mathematical model of excavator. Even after the exact mathematical model is established, it is difficult to design of a controller because the system equations are highly nonlinear and the state variable are coupled. The objective of this study is to design a fuzzy logic controller(FLC) which controls the position of excavator's attachment. This approach enables the transfer of human heuristics and expert knowledge to the controller. Excavation experiments are carried out to check the performance of the FLC.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2003년도 학술대회논문집
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• pp.69-76
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• 2003

In this paper, a novel speed control system that implements the fuzzy logic controller(FLC) is proposed. Fuzzy controller is shown more excellent efficency than a conventional controllers in the strength aspect and non-linear controller using IF-THEN rule which can control without process the accurate mathematical modeling about induction motor. But we cannot expect that conventional fuzzy controller divide equally the space of input and output parameter and use the certain shape of triangle membership function. Therefore to develop the efficiency of conventional fuzzy controller, We need to scale the range of membership functions. In this study, proposed fuzzy controller has the ability controlling scale of membership functions using by output scaling factor.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1992년도 하계학술대회 논문집 A
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• pp.404-407
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• 1992

In this thesis, the algorithm of Fuzzy Logic Control(FLC) is applied to the Nonlinear system to implement a system response. Proportional-Integral-Derivative(PID) controller is also used to control the various systems. Look-up table is applied to decide the control input, and the other look-up table is added for saving memories and inference time. Generally, FLC input variables are error(E) and error derivative($\Delta$E). In this algorithm. another Input variable error's second derivative($\Delta^2$E) is added for Robust Fine control.

• 한국멀티미디어학회논문지
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• 제18권11호
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• pp.1400-1407
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• 2015

In the paper, we suggest bettered EHMECS(Enhanced Hybrid Multi Electrical Cupping System) to regulate automatically vacuum pressure using many cupping cup at once. We controlled accurately the pressure using S-PI control technique in pump motor to input the air inside cupping cup. S-PI control compared constant velocity, load and velocity variance between existing PI and FLC(Fuzzy Logic Control). The stabilization time of suggested S-PI control improve 20% of existing PI and 8% of FLC. The error constant of normal condition improved 71% of existing PI and 62% of FLC in steady speed and 80% of existing PI and 67% of FLC in load change. Also the error constant about velocity variance improve 45% of PI control. It is prove the suggested S-PI control technique. When use long time vacuum pressure of cupping cup regulated the suggested S-PI control technique, can loosen knotted muscles.