• 한국도시철도학회논문집
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• 제6권4호
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• pp.417-426
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• 2018

압전션트는 구조물의 진동을 저감할 수 있는 전기적인 형태의 댐퍼이다. 구조물의 고유진동수에서 발생한 진동은 구조물에 부착된 압전재료를 통해 전기에너지로 변환된다. 전기에너지는 인덕터와 저항으로 구성된 압전션트를 이용하여 열에너지로 소산시켜 진동을 저감할 수 있다. 본 논문에서는 외팔보의 진동을 저감하기 위하여 필요한 최적 인덕턴스에 대한 수식을 검토하고 유한요소해석과 실험을 이용하여 알루미늄 외팔보의 진동을 저감하였다. 유한요소해석에서는 모드형상과 스트레인에너지 분포를 계산하여 부착위치를 검토하고, 인덕턴스와 저항의 회로값을 조절하여 외팔보의 진동저감량을 계산하였다. 또한, 실험에서는 가변인덕터 모듈을 사용하여 외팔보의 특정주파수에서 발생하는 진동을 저감하였다. 결국, 유한요소해석과 실험의 결과를 토대로 압전션트가 외팔보의 진동을 효과적으로 저감할 수 있음을 검증하였다.

• 한국초전도저온공학회:학술대회논문집
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• 한국초전도저온공학회 2001년도 학술대회 논문집
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• pp.176-177
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• 2001

Three nearly identical superconducting fault current limiters (SFCLs) were connected in series to increase the voltage ratings. A slight difference in the quench starting point of individual SFCL units produced significantly imbalanced power distribution when connected in series. The imbalance was successfully removed by connecting a shunt resistor to one SFCL in parallel. 1.2 kV SFCL was designed with five current limiting elements and two or three shunt resistors.

• 전기학회논문지
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• 제67권3호
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• pp.374-382
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• 2018

This paper has done a hardware-based approach to increase the modulation index in 3-phase inverters, unlike the conventional software algorithm-based approaches. The minimum required time to measure the currents in a three-phase inverters with shunt resistors has also been analyzed. By the analysis, the longest time in minimum required time is AD conversion time. To shorten the minimum required time, this paper proposed a sample-and-hold(S/H) circuit implemented at the inverter current signal output to retain the current signal. When the linear operation region of an inverter with S/H was compared with that without it, the modulation index was increased by 7.8 %. Inverters with S/H circuits can employ the traditional software algorithms, such as the voltage injection method or current restoration method, and it will yield further increase the modulation index.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2008년도 춘계학술대회 논문집
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• pp.332-334
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• 2008

The matrix-type superconducting fault current limiter (SFCL) using YBCO thin film consists of the trigger and current-limiting parts. We fabricated the matrix-type SFCL with the integrated current limiting modules. we carried out the experiment of matrix-type SFCL with the integrated current limiting modules connected in series or parallel. We saw current characteristics due to ratio of change the shunt resistance and turns. We confirmed that the difference of critical current between superconducting units was decreased by increment of current flowing into the reactor which applied the magnetic field into the superconducting units..

• 전기학회논문지
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• 제64권8호
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• pp.1186-1192
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• 2015

This paper proposes an economical method that the phase currents can be measured and reconstructed by means of the leg-shunt resistors in the 3-leg 2-phase vector-controlled inverter for 2-phase induction motor. In general, the phase currents of 2-phase induction motor have been measured using two Hall current sensors. However, because Hall current sensors are expensive, economically disadvantageous to apply in low power applications. The proposed method is verified by computer simulations and experiments to show the good performance of the vector control.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2016년도 추계학술대회 논문집
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• pp.224-225
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• 2016

매입형 영구자석 전동기에 가격과 부피를 줄이기 위해 3개의 션트 저항을 이용하는 인버터를 사용하였고 회전자 위치센서를 제거하기 위해 모델기반 센서리스 기법을 사용하였다. TSSI (Three Shunt current Sensing Inverter)의 문제점인 특정 전압 이상에서는 전류를 검출할 수 없는 영역이 생기게 된다. 이를 예측전류를 사용하여 전류복원 불가영역을 개선하였다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2012년도 전력전자학술대회 논문집
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• pp.89-90
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• 2012

본 논문에서는 1개의 홀 전류센서를 사용하여 3상 유도전동기의 벡터제어 인버터를 구현한다. 기존 방식에서는 3상의 전류를 검출하기 위하여 2개의 홀 전류센서를 사용하므로 전체 시스템의 가격이 상승하는 요인이 되었다. 본 논문에서는 시스템의 저가격화를 위해 한 상의 전류는 홀 전류센서를 사용하여 검출하고, 다른 한 상의 전류는 Low-side switch와 DC 링크의 음극 사이에 삽입한 션트 저항을 사용하여 검출하는 방법을 제안하고 컴퓨터 시뮬레이션과 실험을 통하여 성능을 검증한다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.905-906
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• 2007

An intercomparison of ac shunts between the National Research Council of Canada and Korea Research Institute of Standards and Science is presented. The comparison was performed for the recently develop 1 A and 5 A current shunts at KRISS. The results of the both phase angle and ratio error of the resistive shunts are agree within the level of $\pm$1.5ppm and $\pm$5ppm respectively at 50 Hz.

• 한국전기전자재료학회논문지
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• 제30권6호
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• pp.376-380
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• 2017

In this paper, we prepared a metal alloy resistor with stable thermal electro motive force (thermal EMF) as well as a low temperature coefficient of resistance (TCR) by adjusting the manganese proportion from 3 to 12 wt% in the Cu-Mn-Ni alloy. Composition of the fabricated metal alloy was investigated using energy dispersive X-ray (EDX) analysis. The TCR of each sample was measured as 44.56, 40.54, 35.60, and 31.56 ppm for Cu-3Mn-2Ni, Cu-5Mn-2Ni, Cu-10Mn-2Ni, and Cu-12Mn-2Ni, respectively. All the resistor samples were available for the F grade (${\pm}1%$ of the allowable error of resistance) high-precision resistor. All the samples satisfied the baseline of high thermal EMF (under 3 mV at $60^{\circ}C$); however, Cu-3Mn-2Ni and Cu-5Mn-2Ni satisfied the baseline of low thermal EMF (under 0.3 mV at $25^{\circ}C$). We were thus able to design and fabricate the metal alloy resistor of Cu-3Mn-2Ni and Cu-5Mn-2Ni to have low TCR and stable thermal EMF at the same time.

• 한국전기전자재료학회논문지
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• 제32권3호
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• pp.219-222
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• 2019

In this study, we fabricated plate-type shunt resistors with thermal stability by parallelly connecting metal alloy plates with positive temperature coefficient of resistance (TCR) and carbon nanotube (CNT) plates with negative TCR. The metal alloy plates, which were prepared by alloying Cu and Mn with a composition of 91 wt% of Cu and 9 wt% of Mn, showed around $800ppm/^{\circ}C$ of TCR, and the CNT plates prepared from the CNT solution by using the vacuum filtration method showed around $-800ppm/^{\circ}C$ of TCR. The shunt resistor that was fabricated by stacking metal alloy plates and CNT plates in this work showed about $46.93ppm/^{\circ}C$ of TCR. Therefore, we conclude that a shunt resistor with low TCR can be realized by simply adjusting the TCR of the metal alloy only, because the TCR of the CNT plate has an identical value.