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The Explosion Prevention Method for Electrolytic Motor Start Capacitors using Current Characteristic (통전전류 특성을 이용한 모터 기동용 전해 커패시터 폭발 방지 방법)

  • Kim, Jae-Hyun;Park, Jin-Young;Park, Kwang-Muk;Bang, Sun-Bae;Kim, Yong-Un
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.66 no.12
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    • pp.1836-1843
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    • 2017
  • In this paper, we investigated fire cases those are believed to be caused by explosion of a electrolytic motor start capacitor. Using two types of commercially available electrolytic motor start capacitors, capacitor current and the possibility of capacitor explosion were tested. And the ignition possibility of the internal material leaked from a capacitor was also tested. In addition, experiments were conducted to see if the fire could spread when a capacitor was exposed to an external flame. From our test we observed that the current of the electrolytic motor start capacitor rose continuously to a certain level by product, if the capacitor was continuously energized with working voltage, and then the capacitor was exploded. The gas and liquid leaked from the capacitor by the explosion could ignite by an electric arc and an external flame. The capacitor current at explosion was different product by product, but each product had a certain current level at explosion. And the increase rate of the capacitor current until explosion was 24% and 31% for the products used in the experiment. We proposed the capacitor explosion prevention method that cuts off power when the capacitor current rises to a certain threshold level. The proposed method can be used if the current of the applied electrolytic motor start capacitor rises continuously and then the capacitor is exploded at a certain current level when the capacitor is energized continuously.

A Study on the Electrical Characteristics of Battery Capacitor Applied to Photovoltaic Power System (태양광 시스템에 적용한 배터리 커패시터의 전기적 특성에 관한 연구)

  • Mang, Ju-Cheul;Yoon, Jung-Rag
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.66 no.12
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    • pp.1740-1744
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    • 2017
  • This paper describes the preparation and characteristics of a battery capacitor and module for solar power system. A cylindrical 30,000F battery capacitor ($60{\times}138mm$) was assembled by using the $LTO(Li_4Ti_5O_{12})$ electrode as an anode and $NMC(LiNiMnCoO_2)-LCO(LiCoO_2)$ as a cathode. The battery capacitor has reduced energy density and power density under high CC(constant current) and CP(constant power) conditions. Battery capacitor module (16V, 11Ah) was fabricated using an asymmetric hybrid capacitor with a capacitance of 30,000F. In order to determine the characteristics of the battery capacitor Module for solar power system, battery capacitor cells were connected in series with active balancing circuit. As a result of measuring the 100w LED lamp, it was discharged at the voltage of 15V~10V, and the compensation time at discharge was measured to be about 4979s. Experimental results show that it can be applied to applications related to solar power system by applying battery capacitor module.

Fabrication and Electrical Properties of High Reliability Ceramic Capacitor by RF Sputtering (RF Sputtering을 이용한 고신뢰성 Ceramic Capacitor의 제조 및 전기적 특성)

  • Lee, Chang-Bae;Yoon, Jung-Rag;Lee, Kyong-Min
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.300-300
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    • 2010
  • Ceramic capacitor의 에너지내량을 향상시켜 제품의 신뢰성을 높이고자 RF Sputtering을 이용하여 외부전극을 형성하였다. 본 연구에서는 Target의 종류, 증착 시간 및 열처리 유/무에 따른 Ceramic capacitor의 전기적 특성 및 미세구조를 분석하여 최적조건을 확립하였으며, 최적 증착 조건으로 제작한 Ceramic capacitor의 에너지내량을 측정하였다. Target은 Ni target과 Cu target을 사용하였으며, Sputtering 시간은 10, 30, 60분으로 하였다. Sputtering 시간에 따른 Ceramic capacitor의 용량 특성과 손실은 큰 차이가 없었지만, Wire 연결시 Sputtering 시간에 따라 납땜성의 차이가 나타났으며, 증착 시간과 열처리 유/무에 따른 에너지내량의 변화를 확인하였다.

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The Design and Reliability Evaluation of Metallized Film Capacitor for Power Electronic Applications (전력전자용 금속증착 필름 커패시터 설계 및 신뢰성 평가)

  • Yoon, Jung-Rag;Kim, Young-Kwang;Lee, Serk-Won;Lee, Heun-Young
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.24 no.5
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    • pp.381-386
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    • 2011
  • This paper presents the design and reliability evaluation of metallized film capacitor for power e lectronics application. The rated voltage of development capacitor is DC 3300[V], the capacitance is 5 ${\mu}F$ and the ripple current capability is 130 $A_{rms}$. Film metallization and patterns are an important design factor that has been development enhance the electric and reliability properties of film capacitor for power electronics. In term of capacitor construction and metallized pattern is one of the parameters that can be modified to further improve the rating in the terms of maximum ripple current and lifetime. This capacitor can be used as snubber capacitor application such as power train invertor system.

Control of Linear Compressor System Using Virtual AC Capacitor

  • Park, Shin-Hyun;Choi, Jong-Woo
    • Journal of Electrical Engineering and Technology
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    • v.12 no.6
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    • pp.2317-2323
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    • 2017
  • Recently, linear compressors of cooling systems such as refrigerators, which have a free piston driven by a linear motor, have attracted much attention because of their high efficiency. For structural reasons, linear compressors applied in refrigerators should use an AC capacitor to ensure stable control. However, AC capacitors are expensive and bulky. In this paper, we propose a new method to realize stable control without a real AC capacitor by implementing a virtual AC capacitor with software. To realize a virtual AC capacitor, a pure integral is calculated. Nonetheless, if an offset current exists, the calculation may diverge to infinity. To solve this problem, a high-pass filter is applied and the compensation for the phase angle and magnitude are realized with a new method. Finally, a virtual AC capacitor enables variable frequency operations. Hence, in case of a lack of voltage, we can compensate by running the linear compressor in high-frequency operations. To improve efficiency, we may optimize the operation frequency. The validity of a virtual AC capacitor has been verified through simulations and experimental results.

On-chip Decoupling Capacitor for Power Integrity (전력 무결성을 위한 온 칩 디커플링 커패시터)

  • Cho, Seungbum;Kim, Sarah Eunkyung
    • Journal of the Microelectronics and Packaging Society
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    • v.24 no.3
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    • pp.1-6
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    • 2017
  • As the performance and density of IC devices increase, especially the clock frequency increases, power grid network integrity problems become more challenging. To resolve these power integrity problems, the use of passive devices such as resistor, inductor, and capacitor is very important. To manage the power integrity with little noise or ripple, decoupling capacitors are essential in electronic packaging. The decoupling capacitors are classified into voltage regulator capacitor, board capacitor, package capacitor, and on-chip capacitor. For next generation packaging technologies such as 3D packaging or wafer level packaging on-chip MIM decoupling capacitor is the key element for power distribution and delivery management. This paper reviews the use and necessity of on-chip decoupling capacitor.

Ionizing Radiation Sensitivity Analysis of the Structural Characteristic for the MOS Capacitors (MOS 커패시터의 구조별 전리방사선 감도 특성 분석)

  • Hwang, Young-Gwan;Lee, Seung-Min
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.62 no.7
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    • pp.963-968
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    • 2013
  • Ionizing Radiation effects on MOS devices provide useful information regarding the behavior of MOS based devices and circuits in the electronic instrumentation parts and instructive data for making the high sensitive sensors. The study presents the results of the analysis on the structural characteristics of MOS capacitor for sensing the ionizing radiation effect. We performed numerical modeling of Ionizing-radiation effect on MOS capacitor and simulation using Matlab program. Also we produced MOS capacitors and obtained useful data through radiation experiment to analyse the characteristic of ionizing radiation effect on MOS capacitor. Increasing the thickness of MOS capacitor's oxide layer enhanced the sensitivity of MOS capacitor under irradiation condition, but the sensitivity of irradiated MOS capacitor is uninfluenced by the area of MOS capacitor. The high frequency capacitance of the MOS capacitor is found to be strongly affected by incident ionizing radiation.

A Fully Soft Switched Two Quadrant Bidirectional Soft Switching Converter for Ultra Capacitor Interface Circuits

  • Mirzaei, Amin;Farzanehfard, Hosein;Adib, Ehsan;Jusoh, Awang;Salam, Zainal
    • Journal of Power Electronics
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    • v.11 no.1
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    • pp.1-9
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    • 2011
  • This paper describes a two quadrant bidirectional soft switching converter for ultra capacitor interface circuits. The total efficiency of the energy storage system in terms of size and cost can be increased by a combination of batteries and ultra capacitors. The required system energy is provided by a battery, while an ultra capacitor is used at high load power pulses. The ultra capacitor voltage changes during charge and discharge modes, therefore an interface circuit is required between the ultra capacitor and the battery. This interface circuit must have good efficiency while providing bidirectional power conversion to capture energy from regenerative braking, downhill driving and the protecting ultra capacitor from immediate discharge. In this paper a fully soft switched two quadrant bidirectional soft switching converter for ultra capacitor interface circuits is introduced and the elements of the converter are reduced considerably. In this paper, zero voltage transient (ZVT) and zero current transient (ZCT) techniques are applied to increase efficiency. The proposed converter acts as a ZCT Buck to charge the ultra capacitor. On the other hand, it acts as a ZVT Boost to discharge the ultra capacitor. A laboratory prototype converter is designed and realized for hybrid vehicle applications. The experimental results presented confirm the theoretical and simulation results.

콘덴서 런 단상유도전동기의 설계적 고찰

  • 원종수
    • 전기의세계
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    • v.31 no.2
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    • pp.132-140
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    • 1982
  • Designing the capacitor-run motor for balanced operation is accompanied with the excessive capacitor value and low capacitor terminal voltage of condenser. As a solution for this problems, It was reported the design by equal volt-ampere method. The running characteristics of capacitor-run motor by this method due to the balancing point selection, however, has a room to be studied further. This paper deals with the determination of the winding ratio and capacitor value of a permarient-split capacitor motor by balanced operation and equal volt-ampere method at the different load points. The analysis of the running characteristics of a motor and its designing method also presented for both cases. It concluded that the running characteristics due to the equal volt-ampere operation are very close to the balanced operation.

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A High Density MIM Capacitor in a Standard CMOS Process

  • Iversen, Christian-Rye
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.1 no.3
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    • pp.189-192
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    • 2001
  • A simple metal-insulator-metal (MIM) capacitor in a standard $0.25{\;}\mu\textrm{m}$ digital CMOS process is described. Using all six interconnect layers, this capacitor exploits both the lateral and vertical electrical fields to increase the capacitance density (capacitance per unit area). Compared to a conventional parallel plate capacitor in the four upper metal layers, this capacitor achieves lower parasitic substrate capacitance, and improves the capacitance density by a factor of 4. Measurements and an extracted model for the capacitor are also presented. Calculations, model and measurements agree very well.

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