• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2003년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
• /
• pp.253-257
• /
• 2003

This paper presents the Development of Switching Power Supply for testing communication equipment. The communication equipment need many kinds of voltage(-48V,27V,12V,5V,3.3V), and in case of low voltage needs large current($10{\sim}20A$). The previous Linear Power Supply was very heavy, has low efficiency and poor power-factor for testing communication equipment. This development has good efficiency and high power-factor using switch mode power supply technique. This Development of Switching Power Supply is composed of eight converters. The principles of operation, feature, and design considerations are illustrated and verified through the experiment with 600W prototype.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2005년도 심포지엄 논문집 정보 및 제어부문
• /
• pp.84-86
• /
• 2005

The digital systems such as PLC or DCS have been applied to non-safety systems of nuclear power plants because of many difficulties in using analog systems. Nowadays, digital systems have been applied to safety systems of the plants such as reactor protection system. One of the main advantages of digital systems is applicability of automatic testing methods to the systems. The protection system requires high-reliability and high-availability because it shall minimize the propagation of abnormal or accident conditions of nuclear power plants. The calculation of reliability and availability of systems depends on the maintenance period of the system. In general, the maintenance period of the protection system is one-month in case of the manual test. However, the cycle of test can be shortened in several hours by using automatic periodic testing. The reliability and availability of the system is better when test period is shortened because the reliability and availability is inverse proportion to the test period. In this research, we developed the automatic periodic testing method for KNICS Reactor Protection System, which can test the system automatically without an operator or a tester. The automatic testing contained all functions of reaction protection systems from analog-to-digital conversion function of the bistable Processor to the coincident trip function of the coincident processor. By applying the automatic periodic testing to reaction system, the maintenance cost can be cut down and the reliability can be increased.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2008년도 추계학술대회 논문집 전력기술부문
• /
• pp.150-152
• /
• 2008

It is necessary to improve the time efficiency in the high power testing station because tests are mainly performed by high-priced equipment. Minimizing a human error through building the database of relevant standards is possible to expect reliable tests. And also, application program that is properly customized for the certain laboratory's power system will help test engineer to easily analyze the phenomenon that is happened in short-circuit and load switching tests. This paper introduces the several functions of the application program that is developed in order to realize these requirements.

• 한국콘텐츠학회논문지
• /
• 제5권1호
• /
• pp.229-236
• /
• 2005

System-On-a-Chip(SOC)을 테스트하는 동안에 요구되는 테스트 시간과 전력소모는 SOC내의 IP 코어의 개수가 증가함에 따라서 매우 중요하게 되었다. 본 논문에서는 수정된 스캔 래치 재배열을 사용하여 scan-in 전력소모와 테스트 데이터의 양을 줄일 수 있는 새로운 알고리즘을 제안한다. 스캔 벡터 내의 해밍거리를 최소화하도록 스캔 래치 재배열을 적용하였으며 스캔 래치 재배열을 하는 동안에 스캔 벡터 내에 존재하는 don't care 입력을 할당하여 저전력 및 테스트 데이터 압축을 하였으며 ISCAS 89 벤치마크 외호에 적용하여 모든 경우에 있어서 테스트 데이터를 압축하고 저전력 스캔 테스팅을 구현하였다.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2003년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
• /
• pp.116-118
• /
• 2003

This paper describes a Accelerated Life Test (ALT) with the electrical contact erosion suitable to the evaluations of high-reliability and durability devices such as magnetic contactor. Recently, an electrical devices company was interested in accelerated life test (ALT), the product liability (PL) and the short-term testing model of electrical life test (ELT). In order to estimate a model for testing fee and period, need to the statistical analysis method with the acceleration factor(AF). Usually customer/manufacturer regard their device failure to the over-current or heavy duty condition, while devices view shape of contact erosion owing to operational duty problem. In this paper, additional method of evaluation estimated the operated cycles by weight of contact erosion with a used of regression analysis by MINITAB.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2008년도 제39회 하계학술대회
• /
• pp.5-6
• /
• 2008

차단기, 개폐기, 배전반과 같은 전력기기에 대한 성능시험시, 전압과 전류, 제어신호를 측정하고, 필요한 경우 고속카메라를 이용해 시험장면을 촬영한 다음, 이들을 종합적으로 분석하여 시험결과를 판정한다. 이때, 대부분 개별 시스템으로 전압-전류 시험파형과 시험영상을 측정하고 분석하기 때문에, 시간 동기화가 불가능하여 시험현상이나 시료동작특성 분석에 많은 어려움이 있다. 따라서 개별 시스템으로 측정한 신호를 동기 시켜 동시에 분석할 수 있는 프로그램이 있다면, 시험결과 판정뿐만 아니라 시험 중에 발생하는 전기적 과도현상이나 시료의 동작특성분석에 많은 도움이 될 것이다. 이러한 목적을 위해, PT&T에서는 측정시스템과 고속카메라를 이용하여 측정한 전압-전류 시험파형과 시험영상을 동기 시켜 동시에 분석할 수 있는 프로그램인 Dual Viewer를 개발하였다. 본 논문에서는 Dual Viewer에 대한 기능과 특징에 대해 소개하고자 한다.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2008년도 춘계학술대회 논문집 센서 박막재료연구회 및 광주 전남지부
• /
• pp.111-114
• /
• 2008

The paper considers the relation between on-line monitoring and diagnostics on the one hand and high-voltage (HV) withstand and partial discharge (PD) on-site testing on the other. HV testing supplies the basic data (fingerprints) for diagnostics. In case of warnings by on-line diagnostic systems, off-line withstand and PD testing delivers the best possible information about defects and enables the classification of the risk. Because alternating voltage (AC) is the most important test voltage, the AC generation on site is considered. Frequency tuned resonant (ACRF) test systems are best adapted to on-site conditions. They can be simply combined with PD measuring equipment. The available ACRF test systems and their application to electric power equipment -from cable systems to power transformers - is described.

• 한국신뢰성학회지:신뢰성응용연구
• /
• 제17권2호
• /
• pp.136-142
• /
• 2017

Purpose: In this paper, we propose a test method for evaluating the life time of the inverter which is one of the main internal configuration systems in order to evaluate the life time of the power supply for the vehicle. Methods: The performance and failure criteria required for the development of the accelerated life test method were established and the Taguchi method was used to derive the stress factors affecting performance and reliability. Results: The major stress of the product degradation were considered to be high temperature. Conclusion: The acceleration factor was estimated through a two-level high temperature test and a test methods was designed to guarantee the accelerated life time of the inverter.

• Journal of Power Electronics
• /
• 제8권3호
• /
• pp.217-227
• /
• 2008

The electric power subsystems (EPS) of most remote sensing satellites consist of a solar array as a source of energy, a storage battery, a power management and control (PMC) unit and a charge equalization unit (CEU) for the storage battery. The PMC and CEU use high frequency transformers in their power modules. This paper presents a design, implementation and testing results of a high frequency transformer for the EPS of satellite applications. Two approaches are used in the design process of the transformer based on the pre-determined transformer specifications. The transformer is designed based on an ETD 29 ferrite core. The implemented transformer consists of one center-tapped primary coil with eleven center-tapped secondary coils. The offline calculation results and measured values of R, L for transformer coils are convergence. A test circuit for measuring the transformer parameters like voltage, current and B-H hysteresis was implemented and applied. The test results confirm that the voltage waveforms of both primary and secondary coils were as desired. No overlapping occurred between the control signal and the transformer, which was not saturated during testing even during a short circuit test of the secondary channels. The dynamic B-H loop characteristics of the used transformer cores were measured. The sample test results are given in this paper.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2004년도 하계학술대회 논문집 D
• /
• pp.2310-2312
• /
• 2004

In Korea Electric Power Corporation (or KEPCO), several Demand-Side Management (or DSM) program have been carried out to effectively meet electric power demand at least costs by modifying customers electricity use patterns. As one of them, KEPCO applies low-priced night thermal-storage power service for heat appliances to facilitate efficient use of power facilities by shifting relatively high daytime demands to night hours to build loads during the off-peak periods. In the market of heat-storage type water-heater, electric water-heater has been mostly used, but it has low energy efficiency and needs high capacity electric equipments. So in order to replace these electric water heaters, 15 HP air-source heat pump water heater is developed in Korea Electric Research Institute (or KEPRI). This paper shows that measurement system for performance testing of heat pump water heater is established and heating capacity and performance is analyzed and measured for out-door environmental change.