• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2009년도 제40회 하계학술대회
• /
• pp.1427_1428
• /
• 2009

In this paper, we designed and fabricated the ubiquitous thermal sensor unit for high voltage facilities. This sensor unit generates electric power from a current transformer which was mounted in the high voltage wires and transmitted thermal data by using a Zigbee module. We simulated the high voltage facilities that temperature was going up to $80^{\circ}C$ gradually. From the experimental results, it was confirmed that sensibility of the ubiquitous thermal sensor unit is in ranges from $-0.7^{\circ}C$ to $0.3^{\circ}C$.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2002년도 ICCAS
• /
• pp.79.6-79
• /
• 2002

We propose here sequential 2 methods for obtain information of current or potential data for power transmission line. One is a digital data transmission unit, this is, an output of a current sensor of power transmission line is digitalized by use of an easy asynchronous protocol. The unit has high speed transform rate, easy making header caused of consisting of only logic circuit. The other is, the output of the unit is transformed via LAN interface and displayed on a personal computer. We have confirmed remote measuring using the method for 100A and 240 A of the current information of power transmission line. Therefore we will be able to see a current waveform by use of internet at a cheep c...

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2007년도 제38회 하계학술대회
• /
• pp.511-512
• /
• 2007

변전소 자동화 시스템은 변전소 내의 주요 전기적 데이터들을 DB화 하여 그 트렌드 및 이벤트 내역을 관리하고 각종 제어를 수행하고 상태를 감시하는 시스템이다. 현재 전 세계적으로 IEC 61850 프로토콜을 적용하고 그 목적에 맞게 Interoperability를 구현하려는 노력이 진행되고 있으며 이에 맞추어 변전소 및 Utility에 적용되는 많은 시스템들이 IEC 61850의 적용에 박차를 가하고 있는 상황이다. 이에 따라 변전소 내의 주요기기중의 하나인 주 변압기에 설치되어 변압기의 상태를 감시하고 관리하는 IED인 변압기 Local Unit에 사용할 수 있는 새로운 IEC 61850 Local Unit의 Logical Node를 설계한다.

• 전기학회논문지P
• /
• 제62권4호
• /
• pp.175-180
• /
• 2013

This paper presents the design and implementation of a Bicycle Locker System. Generally DC motor has been used to control a Bicycle Locker System, but DC motor system requires frequent maintenances and its power efficiency is comparatively poor especially under heavy load conditions. In order to improve this difficulties, this paper adopts BLDC motor for a Bicycle Locker System and its motor controller is developed. The performances of locker units are compared between DC motor unit and BLDC motor unit. The motor power consumptions between two motors are discussed. Test results verify that power efficiency of the suggested BLDC drive unit is considerably improved compared to the DC drive unit with load condition.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2007년도 제38회 하계학술대회
• /
• pp.1236-1237
• /
• 2007

본 논문에서는 이중여자 유도형 풍력발전기를 제어하기 위한 Power Conditioner Unit을 개발하였다. Power Conditioner Unit은 크게 전력변환을 담당하는 컨버터와 제어기로 구성된다. 컨버터는 2대를 back-to-back 구조로 연결하여 전력을 양방향으로 제어한다. 제어기는 계통의 전압 상태, 발전기의 회전속도와 발전량, 그리고 계통 운영자의 요구에 따라서 발전기의 발전량과 발전 시스템의 출력 역률 또는 계통전압을 제어한다.

• Nuclear Engineering and Technology
• /
• 제50권8호
• /
• pp.1217-1233
• /
• 2018

Following a surge of interest in multi-unit risk in the last few years, many recent studies have suggested methods for multi-unit probabilistic safety assessment (MUPSA) and addressed several related aspects. Most of the existing studies though focused on two-unit nuclear power plant (NPP) sites or used rather simplified probabilistic safety assessment (PSA) models to demonstrate the proposed approaches. When considering an NPP site with three or more units, some approaches are inapplicable or yield very conservative results. Since the number of such sites is increasing, there is a strong need to develop and validate practical approaches to the related MUPSA. This article provides several detailed approaches that are applicable to multi-unit Level 1 PSA for sites with up to six or more reactor units. To validate the approaches, a multi-unit Level 1 PSA model is developed and the site core damage frequency is estimated for each of four representative multi-unit initiators, as well as for the case of a simultaneous occurrence of independent single-unit initiators in multiple units. For this purpose, an NPP site with six identical OPR-1000 units is considered, with full-scale Level 1 PSA models for a specific OPR-1000 plant used as the base single-unit models.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2006년도 추계학술대회 논문집 전력기술부문
• /
• pp.351-353
• /
• 2006

Preventive maintenance can avail the generating unit to reduce cost and gain more profit in a competitive supply-side power market. so, it is necessary to perform reliability analysis on the systems in which reliability is essential. In this paper, FMECA assessment adopted using real historical failure data in Korean power plants for apply RCM analytical method. The stochastic FMECA is an engineering analysis and a core activity performed by reliability engineers to review the effects of probable failure modes of generating unit and assemblies of the power system on system performance. Optimal RCM schedule which is considered the severity level of each generating unit and failure probability from failure prediction of generating unit can be planned using proposed FMECA with IOE index.

• 한국에너지공학회:학술대회논문집
• /
• 한국에너지공학회 2003년도 춘계 학술발표회 논문집
• /
• pp.403-414
• /
• 2003

Periodic safety review on Kori Unit 1 has been successfully done for the first time in Korea. 11 safety factors of the review were fully evaluated in accordance with the domestic legal system. Although it is the oldest nuclear power plant in Korea, Kori Unit 1 was found to have maintained good operating conditions and continuously enhanced its safety by implementing post-TMI action plans and other safety issues, such as replacing steam generators and process/control system. It can be therefore confirmed that safe operation of Kori Unit 1 is guaranteed until next periodic safety review. Nevertheless, some corrective action items were recommended to enhance further its safety level, such as equipment qualification, additional ageing management program, strengthening of some procedures related to administration and human factor. The results of PSR can be utilized for the continued operation beyond the design life as long as the plant safety is maintained and improved. Experiences of the PSR on Kori Unit 1 can be also applied to PSR on other plants.

• 한국정밀공학회지
• /
• 제17권11호
• /
• pp.141-150
• /
• 2000

Continuously variable transmission(CVT) combined differential gear unit has many advantages, which are the decrease of CVT size, the increase of overall efficiency, the extension of speed ratio range, and the generation of geared neutral. It is known that such CVT can be classified into the input coupled type and the output coupled type according to the coupling location of continuously variable unit(CVU). In this paper, six different configurations of input coupled type CVT combined V-belt CVU and 2K-H I type differential gear unit are proposed. Some useful theoretical formula related to speed ratio, power flow and efficiency are derived and analyzed. The propriety of derived formula and theoretical analysis are proven by various experiments.

• 전자공학회논문지B
• /
• 제33B권3호
• /
• pp.193-201
• /
• 1996

The space power system for communication satellite which employs the direct energy transfer (DET) method consists of solar array, battry, shunt regulator, charger/discharger and power control unit (PCU). In this paper, the development of the DET power system charger/discharger unit and a microprocessor based PCU is developed for simplicity and flexiblity in the modificatin of control algorithm. A 28V bus voltage, 400W power rting power simulator is built and tested to verify the operation of the simulator at each mode and the stability of mode transition is analyzed.