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IEC 61850 기반 디지털변전시스템 시험기술 현장 적용
김남대,Kim, Namdae 한국전력공사 2021 KEPCO Journal on electric power and energy Vol.7 No.1
디지털변전소는 IEC 61850 기반 상위운영장치와 IED(Intelligent Electric Device)로 구성된 변전자동화시스템이 적용된 변전소를 의미한다. 한전은 2013 년 이후로 신설되는 154kV 변전소를 디지털변전소로 구축하고 있으며, 기설변전소도 디지털화를 통해 디지털변전소로 변모하고 있다. 이렇게 변전소에 IEC 61850 기반의 변전자동화시스템이 확대 도입됨에 따라 통신 설정과 성능을 검증하는 시험이 반드시 필요하다. 이에 전력연구원은 세계 최고수준의 IEC 61850 기반 디지털변전 시험기술을 확보하였으며, 본 보고서를 통해 연구원이 보유하고 있는 시험기술과 현장에 적용한 사례를 소개하고자 한다.
Aspergillus spp . 에 의한 콩된장 발효 과정중의 효소활성 변화
김남대,주현규,윤기석 한국농화학회 1989 Applied Biological Chemistry (Appl Biol Chem) Vol.32 No.3
This study was carried out as a preliminary test to investigate the improvement of soysauce and soybean paste for natural food. The soybean was treated on raw, soaked, roasted, and steamed condition and it was maked that rice koji was inoculated by Asp. oryzae, Asp. niger, Asp. awamori and on natural condition fermented. They were maked raw soybean-soypaste (S_0), soaked soybean-soypaste (S₁), roasted soybean-soypaste (S₂), and steamed soybean-soypaste (S₃) from soybean (60%), rice koji (30%) and salt (10%) respectively in order to investigate the changes of enzymes activity(amylase, protease, lipase and lipoxygenase activity) during fermentation of them. The results obtained were summarized as follows; Amylase activity was in the order of natural fermented microorganisms$gt; Asp. oryzae$gt; Asp. awamori$gt;Asp. niger in the microorganisms, and S_0$gt;S₁$gt;S₂$gt;S₃, in the soybean treatments. Protease activity was in the order of natural fermented microorganisms$gt;Asp. niger$gt;Asp. oryzae$gt;Asp. awamori in the microorganisms, and S₃$gt;S₂$gt;S₁$gt;S_0 in the soybean treatments. Lipase activity was a similar tendency in the microorganisms, but it was in the order of S_0$gt; S₁$gt; S₃$gt;S₂ in the soybean treatments. Lipoxygenase activity was in the order of natural fermented microorganisms$gt;Asp. oryzae$gt; Asp. awamori$gt;Asp. niger in the microorganisms, and S_0$gt;S₁$gt;S₃$gt;S₂ in the treatments.
Dynamic Reference-based Voltage Droop Control for VSC-MTDC System
김남대,김학만,박재세 대한전기학회 2015 Journal of Electrical Engineering & Technology Vol.10 No.6
The use of voltage source converter multi-terminal direct current (VSC-MTDC) systems is anticipated to increase from the introduction of wind farms and super grids in the near future. Effective control of the DC voltage in VSC-MTDC systems is an important research topic. This paper proposes a new dynamic reference-based voltage droop control to control the DC voltage in VSCMTDC systems more effectively. The main merit of the dynamic reference-based voltage droop control is that it can reduce the steady-state error in conventional voltage droop control by changing references according to the system operating conditions. The performance of the proposed control was tested in a hardware-in-the-loop simulation (HILS) system based on the OPAL-RT real-time digital simulator and four digital signal processing boards.
IEC 61850 기반 디지털변전소 현장정보처리장치 시험 방법에 관한 연구
김남대,김우중,이남호,김석곤,장병태,Kim, Nam-Dae,Kim, Woo-Jung,Lee, Nam-Ho,Kim, Seok-Kon,Jang, Byung-Tae 한국전력공사 2020 KEPCO Journal on electric power and energy Vol.6 No.3
현장정보처리장치는 아날로그형 전력설비의 전압, 전류, 디지털 전기신호를 IEC 61850 기반 데이터로 변환하여 정보를 처리하는 장치이다. 이는 아날로그형 전력설비의 운전 정보를 취득 및 처리하고, 전력설비의 제어를 수행하며, 내부 로직을 이용하여 인터록 기능 등을 수행한다. 특히, 다수의 보호계전기 입출력 신호를 하나의 장치에서 처리하기 때문에 장치의 입출력 정보를 처리하는 데이터 변환시간이 중요하다. 본 논문에서는 현장정보처리장치의 IEC 61850 통신 기능 및 입출력 데이터 변환시간을 측정할 수 있는 시험 방법과 사례를 소개하고자 한다. The local information processing devices are devices that process information by converting voltage, current, and digital electric signals from legacy-type power facility into IEC 61850 based data. It acquires and processes the operation information of legacy-type power facility, performs control of power facility, and interlock function using internal logic. In particular, the time to convert data to process input and output information for a device is important because a number of protection relay input and output signals are handled by only one device. This paper introduces test methods and cases for measuring IEC 61850 communication function and input/output data conversion time of local information processing device.
김남대,주현규,정동곤 한국농화학회 1991 Applied Biological Chemistry (Appl Biol Chem) Vol.34 No.4
The objective of this study was to evalute changes of CO₂ pressure, pH, precipitation, brix, free sugar, colority, crude saponin and ginsenoside contents of Ginseng Drink Product for ten months at different temperatures (room temp., 35℃ and 50℃). The results are as follows : CO₂ pressure was decreased after nine month storage at room temp., six months at 35C and three months at 50℃. pH and brig. nearly constant at various storage temperatures and periods. Precipitation was appeared after five months storage at room temp., two months at 35℃ and one month at 50℃. Sucrose content was decrease, while glucose and fructose contents were increased at high temperature and long period of stroage. Colority and panaxatrial(PT) saponin contents were increased, while panaxadiol(PD) saponin was increased at high temperature and long period of stroage.