A Study on the Miniaturization of a Protective Device for the Micro Smart Grid Simulator

Yun‑Seok Ko,Kyung Ryu,Min‑Soo Oh,Hyuk‑Sik Yoon 대한전기학회 2020 Journal of Electrical Engineering & Technology Vol.15 No.1

In this paper, a miniaturization methodology of protective devices (PDs) was proposed which plays a key role in evaluating the efectiveness of the developed protection and control algorithms in the micro smart grid simulator. The micro PD was designed to have the rated voltage of 19 V and the breaking current of 20 A, and was designed in a multi-layered hardware structure to satisfy the size of 13×13 cm2 . Also, the micro PD was designed in a multifunctional structure to allow one micro PD to perform all the functions of the circuit breaker, recloser and switches on the micro smart grid simulator to enhance the efciency of development. Finally, it was verifed that the developed micro PD can be applied as protective devices of the micro smart grid simulator by showing that it operates correctly according to the predetermined operation sequence for the test scenarios on the built test system.

DC서보 모터를 이용한 속도 제어계 설계 방법론에 대한 연구

고윤석 남서울대학교 2004 남서울대학교 논문집 Vol.10 No.-

DC servo control system is utilized in the fields ranging from automatic machining tools such as NC machine and industrial robotics to computer periphery device such as disk driver, word processor because that its analysis and design is simple due to the low time-constant nature and the linearity of speed-torque control system. Accordingly, This paper studies on the design methodologies of speed control system using DC servo motor which is utilized widely in industrial area. First, DC servo configurations are analyzed. Especially, the design methodologies of the driving circuit are proposed by discussing the driving principal and design methodologies for the linear amplifier and PWM amplifier. Next, the design methodologies for DC servo control system are discussed by introducing the configurations and applications for diversity the analog speed control system and digital speed control system. It is expected that this study results play an important role in designing and implementing DC servo control system.

너비제한 탐색법에 근거한 주변압기 과부하 해소 전략 설계 및 구현

고윤석 남서울대학교 2005 남서울대학교 논문집 Vol.11 No.2

Most of the existing expert system applications to the main transformer overload problem events adopts the best-first search method guided by heuristic as problem-solving strategy. This search method has an advantage which can determine in real-time the control strategy satisfying the operating constraints by minimizing the search space, but has a disadvantage which can not guarantee the optimal solution. Accordingly, this paper proposes the releasing strategy of the main transformer overload based on the breadth-limitation search, which makes it possible to obtain the solution of more improved performance by limiting the search space within the extent of real-time constraints. Finally, the effectiveness and the accuracy of the proposed control strategy are verified by simulation work for the given test distribution system.

매트랩을 활용한 차수 줄임형 관측기 설계에 대한 연구

고윤석 남서울대학교 공학연구센터 2001 공학연구 Vol.2 No.-

This paper designs the state vector feedback control system to obtain arbitrary poles using the canonical form when the states of plant is unobservable The functional observer is adopted in order to estimate the unobservable states as the observer of minimum order. The state vector feedback system and the reduced order observer for the linear single input, multiple output are simulated using MATLAB under the 586 PC. Also, it is expected that this design methodology can be applied to linear time-invariant system as well as time-variant, nonlinear system.

이산 프리에 변환(DFT)기법의 배전계통 HIF 해석 적용을 위한 기초기술 연구

고윤석 남서울대학교 2007 남서울대학교 논문집 Vol.13 No.3

ABSTRACT : It is very difficulty to detect the HIF(High Impedance Fault) ofdistribution system is very difficulty because that the current variation isvery little by high impedancefault circuit. And, the spread effect of thefault is very severe including a loss of human lives. Accordingly, in thispaper, the HIF analysis methodology of distribution is studied on thebased on DFT(Discrete Fourier Transformation). At first, the main topicsare analyzed such as the typical distribution configuration, diversityevents and DFT. The basic technology for the detection of HIF ofdistribution system basedon DFT method is analyzed by applying theDFT method to the real measured HIF waveform. Here, the waveform isobtained bygenerating the artificial HIF using an artificial faultequipment.

배전자동화 시스템의 구성 및 기능분석에 대한 연구

고윤석 남서울대학교 2002 남서울대학교 논문집 Vol.8 No.-

This paper surveys and analyses the configuration and function of distribution automation system which is able to correspond effectively to requirements of high quality power. it analyses the configuration relationship between distribution system and distribution automation system in overall distribution automation system composition. Also it surveys hardware composition of distribution automation system, intelligent alarm processor, and feeder automation software, database. Expecially methodology searching the connectivity of distribution system is proposed through relationship among databases in distribution database. Also relationship between distribution SCADA and power SCADA is surveyed. It is expected that this study results can be utilized as basic data for automation of distribution system.

Lifting을 이용한 고저항 고장 검출에 관한 연구

고윤석,홍대승 남서울대학교 2004 남서울대학교 논문집 Vol.10 No.2

The research presented in this paper focuses on a method for the detection of High Impedance Fault(HIF). The method will use the Lifting and neural network system. HIF on the multi-grounded three-phase four-wires primary distribution power system cannot be detected effectively by existing over current sensing devices. These paper describes the application of lifting scheme to the various HIF data. These data were measured in actual 22.9kV distribution system. Wavelet transform analysis gives the frequency and time-scale information. The neural network system as a fault detector was trained to discriminate HIF from the normal status by a gradient descent method. The proposed method performed very well by proving the right state when it was applied staged fault data and normal load mimics HIF, such as arc-welder.

전문가 시스템의 전력계통 적용 현황 및 개발환경에 대한 고찰

고윤석 남서울대학교 공학연구센터 2002 공학연구 Vol.3 No.-

This paper surveys and analyzes the applications and its fields of expert system to the power system. The development tools and languages of expert system is surveyed, which is required in the process of design and implementation of expert system in the field of electric power system. Basic conditions required to apply development tools of expert system to power system is analyzed and described. It is expected that this study results can be utilized as effective methodology for expert system application.

저압 아크 고장 차단 기술에 대한 기초 조사 연구

고윤석 남서울대학교 2008 남서울대학교 논문집 Vol.14 No.-

The ELCB(Earth Leakage Circuit Breaker) determines whether the earth leakage is or not by comparing the sensitive current furnished from ZCT(Zero Current Transformer) with the predefined threshold value. However, it can not recognize the arc fault in which the magnitude of fault current is very small and so, the arc fault is expanded into very severe electrical fire. The America has propelled making the laws for the arc fault protection from 1999, and NEC(National Electrical Code) defines and mandates the installation of the AFCI(Arc Fault Current Interrupter)s in diverse places such as bedroom, living room, dinner room, sunroom and closets in 2008. GE and Siemens developed the determination technology of arc fault by making R&D effort for AFCI practicalization, and to mitigate the electrical fire, the developed AFCIs are applied widely to home. However, the effort of us about this field is insufficient, and the level also is very low. Accordingly, this paper surveys and analyzes systematically the basic technology needed in developing the arc fault determination technology. Key Words : AFCI, Electrical Panel, ELCB, ZCT, NEC

시각장애인을 위한 RFID 기반 실내 내비게이션 알고리즘

고훈,윤석중,권호열 강원대학교 정보통신연구소 2008 정보통신논문지 Vol.12 No.-

In this paper, we propose an RFID based indoor navigation system for visually impaired person using RFID tags, a RFID reader and a compass sensor. In our system, the RFE tags regularly installed like a grid pattern on the floor in a building and they provide directions to reach the destination. The navigation system recognizes the RFID tags by an RFID) reader, calculates the next direction using RFID data and a compass sensor, and finally guides user to the destination. We presented the proposed system with its performance evaluations.