• Journal of Electrical Engineering and Technology
• /
• 제7권3호
• /
• pp.312-319
• /
• 2012

The life of a power transformer is dependent on the life of the cellulose paper, which influenced by the hot spot temperature. Thus, the determination of the cellulose paper's life requires identifying the hot spot temperature of the transformer. Currently, however, the power transformer uses a heat run test is used in the factory test to measure top liquid temperature rise and average winding temperature rise, which is specified in its specification. The hot spot temperature is calculated by the winding resistance detected during the heat run test. This paper measures the hot spot temperature in the single-phase, 154kV, 15/20MVA power transformer by the optical fiber sensors and compares the value with the hot spot temperature calculated by the conventional heat run test in the factory test. To measure the hot spot temperature, ten optical fiber sensors were installed on both the high and low voltage winding; and the temperature distribution during the heat run test, three thermocouples were installed. The hot spot temperature shown in the heat run test was $92.6^{\circ}C$ on the low voltage winding. However, the hot spot temperature as measured by the optical fiber sensor appeared between turn 2 and turn 3 on the upper side of the low voltage winding, recording $105.9^{\circ}C$. The hot spot temperature of the low voltage winding as measured by the optical fiber sensor was $13.3^{\circ}C$ higher than the hot spot temperature calculated by the heat run test. Therefore, the hot spot factor (H) in IEC 60076-2 appeared to be 2.0.

• ETRI Journal
• /
• 제33권1호
• /
• pp.140-143
• /
• 2011

Recent test data compression techniques raise concerns regarding power dissipation and compression efficiency. This letter proposes a new test data compression scheme, twin symbol encoding, that supports block division skills that can reduce hardware overhead. Our experimental results show that the proposed technique achieves both a high compression ratio and low-power dissipation. Therefore, the proposed scheme is an attractive solution for efficient test data compression.

• 한국자동차공학회논문집
• /
• 제24권1호
• /
• pp.90-98
• /
• 2016

Currently government certified test method for an automobile remanufactured products is insufficient. Thus many automotive parts in the remanufacturing market are lacking proper evaluation criteria and production of defective products are causing customer dissatisfaction. In this paper a power steering oil pump, which requires stringent manufacturing standards, is studied by the failure mode and effect analysis approach. The research suggested that the test criteria such as discharge flow characteristic test, tightness test, pulley run-out test, pressure switch operation test, low temperature test and rotation pressure durability test should be performed to evaluate the reliability of remanufactured power steering oil pumps. As a result of tests, the performance of remanufactured power steering oil pump satisfied the evaluation criteria of pressure switch operation test and low temperature test. However, the remanufactured power steering oil pump failed to satisfy the evaluation criteria on discharge performance test, tightness test and pulley run-out test. These performance evaluation tests proved the necessity of standard process for the remanufactured power steering oil pump.

• 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.

• 한국정보통신학회논문지
• /
• 제12권3호
• /
• pp.555-562
• /
• 2008

본 논문에서는 RTL 수준에서의 클록 게이팅을 이용한 실제적인 저전력 설계 기술에 대해서 제안하고자 한다. 상위 수준의 회로 설계자에 의해 시스템의 동작을 분석하여 클록 게이팅을 위한 제어기를 이용하는 것이 가장 효율적인 전력 감소를 가져 온다. 또한 직접적으로 클록 게이팅을 수행하는 것보다는 합성툴이 자연스럽게 게이팅된 클록을 맵핑할 수 있도록 RTL 수준에서 유도하는 것이 바람직하다. RTL 코딩 단계에서부터 저전력이 고려되었다면 처음 코딩단계에서부터 클록을 게이팅 시키고, 만일 고려되지 않았다면 동작을 분석한 후에 대기 동작인 부분에서 클록을 게이팅 한다. 그리고 회로의 동작을 분석한 후에 클록의 게 이팅을 제어하기 위한 제어기를 설계하고 합성 툴에 의해 저전력 회로에 해당하는 netlist를 얻는다. 결과로부터 상위수준의 클록 게이팅에 의해 레지스터의 전력이 922 mW에서 543 mW로 42% 감소한 것을 확인할 수 있다. Power Theater 자체의 synthesizer를 이용하여 netlist로 합성한 후에 전력을 측정했을 경우에는 레지스터의 전력이 322 mW에서 208 mW로 36.5% 감소한 것을 확인할 수 있다.

• 국제물리치료학회지
• /
• 제3권1호
• /
• pp.345-355
• /
• 2012

This study purposed to examine the effect of low power laser on pain response and axonal regeneration. In order to prepare peripheral nerve injury models, we crushed the sciatic nerve of Sprague-Dawley rats and treated them with low power laser for 21 days. The rats were divided into 4 groups: normal group(n=10); control group(n=10) without any treatment after the induction of sciatic nerve crush injury; experimental group I(n=10) treated with low power laser(0.21$mJ/mm^2$) after the induction of sciatic nerve crush injury; and experimental group II(n=10) treated with low power laser(5.25$mJ/mm^2$) after the induction of sciatic nerve crush injury. We measured spontaneous pain behavior(paw withdrawal latency test) and mechanical allodynia(von Frey filament test) for evaluating pain behavioral response, and measured the sciatic function index for evaluating the functional recovery of peripheral nerve before the induction of sciatic nerve crush injury and on day 1, 7, 14 and 21 after the induction. After the experiment was completed, changes in the H & E stain and toluidine blue stain were examined histopathologically, and changes in MAG(myelin associated glycoprotein) and c-fos were examined immunohistologically. According to the results of this study, when low power laser was applied to rat models with sciatic nerve crush injury for 21 days and the results were examined through pain behavior evaluation and neurobehavioral, histopathological and immunohistological analyses, low power laser was found to affect pain response and axonal regeneration in both experimental group I and experimental group II. Moreover, the effect on pain response and axonal regeneration was more positive in experimental group I to which output 0.21$mJ/mm^2$ was applied than in experimental group II to which 5.25$mJ/mm^2$ was applied.

• Journal of Electrical Engineering and Technology
• /
• 제8권1호
• /
• pp.156-162
• /
• 2013

This paper measures the hot spot temperatures in a single-phase, 154 kV, 15/20 MVA power transformer filled with natural ester fluid using optical fiber sensors and compares them with those calculated by conventional heat run tests. A total of 14 optical fiber sensors were installed on the high-voltage and low-voltage windings to measure the hot spot temperatures. In addition, three thermocouples were installed in the transformer to measure the temperature distribution during the heat run tests. In the low-voltage winding, the hot spot temperature was $108.4^{\circ}C$, calculated by the conventional heat run test. However, the hot spot temperature measured using the optical fiber sensor was $129.4^{\circ}C$ between turns 2 and 3 on the upper side of the low-voltage winding. Therefore, the hot spot temperature of the low-voltage winding measured using the optical fiber sensor was $21.0^{\circ}C$ higher than that calculated by the conventional heat run test.

• JSTS:Journal of Semiconductor Technology and Science
• /
• 제16권4호
• /
• pp.463-469
• /
• 2016

This paper presents a compression-friendly low power test scheme in EDT environment. The proposed approach exploits scan slices reusing to reduce the switching activity during shifting for test scheme based on linear decompressor. To avoid the impact on encoding efficiency from resulting control data, a counter is utilized to generate control signals. Experimental results obtained for some larger ISCAS'89 and ITC'99 benchmark circuits illustrate that the proposed test application scheme can improve significantly the encoding efficiency of linear decompressor.

• 대한전자공학회논문지SD
• /
• 제39권12호
• /
• pp.1045-1054
• /
• 2002

System-On-a-Chip(SOC)에 대하여 테스트 데이터 압축 및 저전력 스캔테스팅에 대한 새로운 알고리즘을 제안하였다. 스캔벡터내의 don't care 입력들을 저전력이 되도록 적절하게 값을 할당하였고 높은 압축율을 갖도록 적응적 인코딩을 적용하였다. 또한 스캔체인에 입력되는 동안 소모되는 scan-in 전력소모를 최소화하도록 스캔벡터의 입력 방향을 결정하였다. ISCAS 89 벤치마크 회로에 대하여 실험한 결과는 평균전력 소모는 약 12% 감소되었고 압축율은 약 60%가 향상됨을 보였다.

• 조명전기설비학회논문지
• /
• 제29권9호
• /
• pp.59-64
• /
• 2015

IEC is an international standards which are used in many countries with Europe as the center. IEC standard is introduced in Korea according to WTO/TBT agreements, however until now there are no buildings in Korea which are designed applying IEC standard. Therefore, KEA(Korea Electric Association) is scheduled to construct Korean low voltage electrical installation integration test site which is designed applying IEC standard. In this paper, before being under construction of Korean low voltage electrical installation integration test site, power substation is modeled based on real design parameters and method to select circuit breakers and cables is presented applying IEC standard in the modeled power substation. EMTP(ElctroMagnetic Transient Program) is used for simulation program. EMTP which is power system analysis program is easy to model power system and power substation.