DSP를 이용한 변압기용 디지털 보호계전기 설계에 관한 연구

서희석,권기백 한국조명전기설비학회 2003 조명·전기설비학회논문지 Vol.17 No.6

In this papers, We studied system requirement specification, hardware design and implementation, protective algorithm and software design method to implement digital protective relay which has high trust and high function of protection as well as control and metering for power transformers. Protective relay for transformer is implemented on real time using DSP, which is the specific processor for digital signal processing, as a result, it is completed by the wide improvement of arithmetic capability of protective relay. Reliability is proved testing operating value and operating time, reset value and reset time of an relaying element using protective relay tester made in NF Corporation of Japan. 본 논문에서는 디지털화 경향에 맞추어 변압기를 보호함과 아울러 감시 및 계측 등의 기능을 갖춘 변압기용 디지털 보호계전기를 개발하기 위한 하드웨어 및 실시간 처리가 가능한 소프트웨어의 구현 방법 등을 제시하였다. 특히 보호계전기의 모든 알고리즘 및 보조 프로그램들이 단일 프로세서에 의해 실시간으로 수행될 수 있도록 DSP의 DMA 제어기를 이용하여 아날로그 입력 데이터를 처리하였다. 아울러 비휘발성 메모리 (EEPROM, flash memory)에 보호계전 알고리즘의 수행에 필요한 각종 설정치, 이벤트 및 고장데이터를 저장하고 UART를 이용하여 데이터를 분석할 수 있도록 하였다. 그리고 시험용 변압기용 디지털 보호계전기를 제작하여 일본 NF 사의 보호계전기 시험기를 이용하여 변압기 보호기능 및 동작특성을 시험하여 그 성능을 입증하였다.

열 모델을 이용한 전동기 보호성능 개선

장중구(Choong-koo Chang) 대한전기학회 2015 전기학회논문지 Vol.64 No.3

Thermal relays are sometimes used instead of long time overcurrent relays for motor protection. But, it is difficult for any relay design engineer to adequately approximate motor heating curves which represent the average of a difficult-to-define thermal zone. Thermal relays frequently may not provide sufficient protection on heavy overloads. Digital multifunction relays are microprocessor-based devices. These relays offer highly reliable and advanced protection of motors. If a situation can be mathematically described, the microprocessor in a digital relay can be programmed to tackle that problem. Today’s motor protection is accomplished with digital protective relays. Digital relays offer additional, highly important features to complement protection. The best way to prevent short in motor is to not overheat and degrade the insulation.

IMT-A 시스템에서의 시분할 Duplex 무선 디지털 중계기 특유의 2가지 동작방식

댜오신시,쉬링,마쯔펑,후짼 에스케이텔레콤 (주) 2009 Telecommunications Review Vol.19 No.3

본 논문에서는 TDD Digital Wireless Relay(DWR)의 2가지 특유의 동작 모드를 소개하는데 Concurrent Transmission and Reception(CTR) 작동 모드와 듀얼 안테나 세트 및 TDD Digital Wireless Relay의 RF 채널이 다. CTR을 구현하는 원리를 소개한 후 CTR에 의해 향상된 효율성을 분석한다. 그리고 셀 내부와 셀간의 간섭요소 를 논의한다. Inverse Transmission and Reception(ITR)의 2개 TDD 대역 작동 모드는 주파수 집합에 의한 듀얼 대역 TDD 시스템 CTR 작동 모드의 확장방식이다. ITR 작동 모드에서 피드백 속도를 향상할 수 있고 릴레이 지연을 감소할 수 있다. 이로 하여 DWR의 전송 효율을 향상시킬 수 있다. CTR 및 ITR 작동 모드는 IMT-Advanced TDD 시스템의 퍼포먼스를 향상하는데 사용될 수 있다.

Performance Analysis of the Threshold Digital Relaying M2M System

보안공학연구지원센터(IJSIP) 보안공학연구지원센터 2015 International Journal of Signal Processing, Image Vol.8 No.3

Exact closed-form outage probability (OP) expressions are presented for multiple-mobile relay-based mobile-to-mobile (M2M) systems with threshold digital relaying (TDR) and relay selection over N-Nakagami fading channels. Numerical simulation is used to verify the accuracy of the analytic results. The effect of the fading coefficient, the number of cascaded components, the relative geometric gain, and the power-allocation on the OP is examined.

Development of an Impedance Locus Model for a Protective Relay Dynamic Test with a Digital Simulator

Kim, Soo-Nam,Lee, Myoung-Soo,Lee, Jae-Gyu,Rhee, Sang-Bong,Kim, Kyu-Ho The Korean Institute of Electrical Engineers 2011 Journal of Electrical Engineering & Technology Vol.6 No.2

This paper presents a method for the development of the impedance locus to test the dynamic characteristics of protective relays. Specifically, using the proposed method, the impedance locus can comprise three impedance points, and the speed of impedance trajectory can be adjusted by frequency deviation. This paper is divided into two main sections. The first section deals with the configuration of impedance locus with voltage magnitude, total impedance magnitude, and impedance angle. The second section discusses the control of the locus speed with the means of the deviation between two frequencies. The proposed method is applied to two machine equivalent systems with offline simulation (i.e., PSCAD) and real-time simulation (i.e., real-time simulation environment) to demonstrate its effectiveness.

Development of an Impedance Locus Model for a Protective Relay Dynamic Test with a Digital Simulator

Soo-Nam Kim,Myoung-Soo Lee,Jae-Gyu Lee,Sang-Bong Rhee,Kyu-Ho Kim 대한전기학회 2011 Journal of Electrical Engineering & Technology Vol.6 No.2

This paper presents a method for the development of the impedance locus to test the dynamic characteristics of protective relays. Specifically, using the proposed method, the impedance locus can comprise three impedance points, and the speed of impedance trajectory can be adjusted by frequency deviation. This paper is divided into two main sections. The first section deals with the configuration of impedance locus with voltage magnitude, total impedance magnitude, and impedance angle. The second section discusses the control of the locus speed with the means of the deviation between two frequencies. The proposed method is applied to two machine equivalent systems with offline simulation (i.e., PSCAD) and real-time simulation (i.e., real-time simulation environment) to demonstrate its effectiveness.

계통변화를 고려한 자율 적응형 과전류 계전기

尹晙碩,崔勉松,李承宰,玄升鎬 明知大學校 産業技術硏究所 2004 産業技術硏究所論文集 Vol.23 No.-

In this paper present Autonomous Adaptive Digital Over Current Relay for distribution networks which acts autonomous setting using the short circuit impedance measured by relay of power systems. Automation of relay setting is one of the basic requirements for distribution automation, although manual relay setting is used at present. The short circuit impedance from a power source in distribution networks essential for the Autonomous Relay Setting changes frequently in distribution networks. In this paper the short circuit impedance is calculated with voltage and current measured in real time operation of digital relay using the Recursive Least Squares. A new method of digital relay setting in introduced using the the short circuit impedance and load current.

디지털 제어 기법을 이용한 형상기억합금 와이어의 온도 제어에 관한 연구

정상화(Sang-Hwa Jeong),김주환(Ju-Hwan Kim) 한국기계가공학회 2007 한국기계가공학회 춘추계학술대회 논문집 Vol.2007 No.-

Actuator of the robot is an important technology. One of the possible actuator is to drive by shape memory alloy. Shape memory alloy has the excellent corrosion and the heat resistance. But, there is bad performance of repeatibility and the control scheme of SMA is difficult. In this paper, the control of SMA wire using digital control method is studied. The SMA wire is segmented by thermoelectric module(TEM). The temperature control program of segmented SMA wire is developed by using LabVIEW. Temperature control module measures the temperature of TEMs through thermocouple. Relay control module turns on or off the relay by comparing the measured temperature with the threshold temperature. To evaluate the performance of SMA wire using digital control method, the reaction time and the displacement are measured in each segment.

Digital Relaying Algorithm for Power Transformer Protection using Fuzzy Logic Approach

Park, Chul-Won,Shin, Myong-Chul The Korean Institute of Electrical Engineers 2002 KIEE International Transactions on Power Engineeri Vol.a2 No.4

Power transformer protective relay should block the tripping during magnetizing inrush and rapidly operate the tripping during internal faults. Recently, the frequency environment of power system has been made more complicated and the quantity of 2nd frequency component in inrush state has been decreased because of the improvement of core steel. And then, traditional approaches will likely be maloperate in the case of magnetizing inrush with low second harmonic component and internal faults with high second harmonic component. This paper proposes a new relaying algorithm to enhance the fault detection sensitivities of conventional techniques by using a fuzzy logic approach. The proposed fuzzy based relaying algorithm consists of flux-differential current derivative curve, harmonic restraint, and percentage differential characteristic curve. The proposed relaying was tested with relaying signals obtained from EMTP simulation package and showed a fast and accurate trip operation.

동일 채널 이중편파를 적용하는 디지털 무선 중계장치의 직교편파간섭제거기 설계에 관한 연구

서경환 한국전자파학회 2002 한국전자파학회논문지 Vol.13 No.3

본 논문에서는 동일채널 이중편파를 적용하는 디지털무선중계장치의 직교편파간섭을 제거할 목적으로 직교편파간섭제거기(XPIC)의 이론적 모델링, 디지털 설계를 분석하였다. 또한 유한임펄스응답 여파기를 이용한 복소 시간영역 적응등화기(ATDE)를 설계하고, 이를 이용한 XPIC의 구조 및 제어방법을 ATDE와의 연동하여 제시하였다. XPIC와 ATDE를 연동으로 약 25㏈ 이상의 시그너쳐(signature)와 약 23㏈ 이상의 XPIC 개선인자를 얻을 수 있음을 모의실험으로 보였다. 설계된 직편파간섭제거기의 동작검증을 위해 동일채널 이중편파용의 64-QAM모뎀과 연동하여 탭의 수, 알고리즘의 수렴, 장치의 성능, 직교편파간섭제거기의 개선인자에 대한 결과도 검토하였다. In this paper, to counteract a cross-polarization interference caused by co-channel dual polarization technique of digital radio relay system(DRRS), we analyze the theoretical model and digital design of cross-polarization interference canceller(XPIC). In addition a complex adaptive time domain equalizer(ATDE) is designed using a finite impulse response filter, and the structure of XPIC and its control method are also illustrated including ATDE. Our computer simulation shows that about 25 dB signature and more than 23 dB XPIC improvement factor can be obtained with XPIC and ATDE. In order to verify the operation of designed XPIC, we review the simulated results in view of tap number, algorithm convergence, system signature, and XPlC improvement factor in connection with 64-QAM DRRS with co-channel dual polarization.