• 제목/요약/키워드: Capacitor lifetime

검색결과 49건 처리시간 0.023초

전해 캐패시터의 최적 가속시험방법과 수명예측 (The best accelerated method and lifetime prediction of electrolytic capacitors)

  • 김하나;심찬호;김성준;윤중락;이헌용
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2005년도 제36회 하계학술대회 논문집 C
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    • pp.1945-1947
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    • 2005
  • This study considers find out best accelerated life testing and lifetime prediction of electrolytic capacitors. We proved about relation between failure and deterioration mechanism from last thesis. Beside we performed test that temperature and voltage press higher than allowance specification. Failure distribution acquired from those test. And wiebull function and Minitab program applied to accelerated constant and lifetime by means of calculation. At the result, goodness of fit affect to weibull function and acceleration factor therefore fitting is important factor in reliability testing.

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LED 구동전류의 피크값이 저감된 전해 커패시터 없는 AC-DC 컨버터 (AC-DC Converter for Electrolytic Capacitor-less LED Driver with Reduced LED Peak Current)

  • 강경숙;박권식;서병준;노의철
    • 전력전자학회논문지
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    • 제23권1호
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    • pp.59-65
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    • 2018
  • A new single-stage flyback power converter with PFC for electrolytic capacitor-less LED driver is proposed in this study. This method minimizes the peak-to-average ratio of the LED driving pulsating current by adding the LED driving current near the LED current valley area, as well as the third harmonic component injection into the input current. The reduced peak current value of the LED drive current minimizes the thermal stress of the LED itself, thereby increasing the reliability of the LED, as well as achieving a long lifetime. Simulation and experimental results show the usefulness of the proposed topology.

Third Harmonic Injection Circuit to Eliminate Electrolytic Capacitors in Light-Emitting Diode Drivers

  • Yoo, Jin-Wan;Jung, Kwang-Hyun;Jeon, In-Ung;Park, Chong-Yeun
    • Journal of Electrical Engineering and Technology
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    • 제7권3호
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    • pp.358-365
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    • 2012
  • A new third harmonic injection circuit for light-emitting diode (LED) drivers is proposed to eliminate electrolytic capacitors and thereby extend the lifetime of LED drivers. When a third harmonic current is injected to the input current of the LED driver, the required capacitance of the driver can be reduced. The proposed circuit can control an injection ratio and has simple circuitry. The synchronous third harmonic is generated by a phase locked loop (PLL), a 1/3 counter, and op-amps and applied to a power factor correction circuit. Thus, the storage capacitor can install film capacitors instead of the electrolytic capacitor. The value of storage capacitance can be reduced to 78% compared to an input power factor of 100%. The proposed circuit is applied to the 80W prototype LED driver to experimentally verify the performances.

전력 디커플링 기능을 가진 단상 계통연계 전압형 인버터 (Single Phase Grid Connected Voltage-ed Inverter Utilizing a Power Decoupling Function)

  • 이상욱;문상필;박한석
    • 전기학회논문지P
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    • 제66권4호
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    • pp.236-241
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    • 2017
  • This paper presents a single-phase grid connected voltage-ed inverter with a power decoupling circuit. In the single-phase grid connected voltage-ed inverter, it is well known that a power pulsation with twice the grid frequency is contained in the input power. In a conventional voltage type inverter, electrolytic capacitors with large capacitance have been used in order to smooth the DC voltage. However, lifetime of those capacitors is shortened by the power pulsation with twice grid frequency. The authors have been studied a active power decoupling(APD) method that reduce the pulsating power on the input DC bus line, this enables to transfer the ripple energy appeared on the input DC capacitors into the energy in a small film capacitor on the additional circuit. Hence, extension of the lifetime of the inverter can be expected because the small film capacitor substitutes for the large electrolytic capacitors. Finally, simulation and experimental results are discussed.

분산전원을 포함한 배전계통에서 설치비용과 유지보수 비용을 고려한 병렬 캐패시터-리액터 Bank의 최적 설치 위치 선정 (Optimal Allocation of Shunt Capacitor-Reactor Bank in Distribution System with Dispersed Generators Considering Installation and Maintenance Cost)

  • 허재행;류재근;이우리;박종영;박종근
    • 전기학회논문지
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    • 제62권11호
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    • pp.1511-1519
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    • 2013
  • This paper proposes the allocation method for capacitor-reactor banks in a distribution system with dispersed generators to reduce the installation costs, the maintenance costs and minimize the loss of electrical energy. The expected lifetime and maintenance period of devices with moving parts depends on the total number of operations, which affects the replacement and maintenance period for aging equipment under a limited budget. In this paper, the expected device lifetimes and the maintenance period are included in the formulation, and the optimal operation status of the devices is determined using a genetic algorithm. The optimal numbers and locations for capacitor-reactor banks are determined based on the optimal operation status. Simulation results in a 69-bus distribution system with the dispersed generator show that the proposed technique performs better than conventional methods.

배전계통 전압/무효전력조정을 위한 새로운 전압/무효전력제어 방식 (A New Volt/Var Control of Substation for Distribution Volt/Var Regulation)

  • 최준호;김재철;손학식;임태훈
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2001년도 하계학술대회 논문집 A
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    • pp.285-288
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    • 2001
  • In this paper we proposed the on line volt/var control schemes of the load Tap Changer (LTC) transformer and shunt capacitor bank for distribution volt/var regulation. In the existing volt/var control of the distribution substation, the voltage of feeders and var of distribution systems is mainly controlled by the LTC transformer tap position and on/off status of the shunt capacitor. The LTC and shunt capacitor bank has discrete operation characteristics and therefore it is very difficult to control volt/var at the distribution networks within the satisfactory levels. Also there is limitation of the operation times of the LTC and shunt capacitor bank because it is affects on their functional lifetime. The proposed volt/var control algorithm determine an optimal tap position of LTC and on/off status of shunt capacitors at a distribution network with the multiple feeders. The mathematical equations of the proposed method are introduced. Simple case study was performed to verify the effectiveness of the proposed method.

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배전계통 전압/무효전력 보상을 위한 LTC변압기와 SC의 협조운전 알고리즘 (Cooperation Algorithms of LTC and SC for Distribution Volt/Var Regulation)

  • 최준호;김재철;남해곤;문승일
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2003년도 하계학술대회 논문집 A
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    • pp.399-402
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    • 2003
  • In this paper, the on line volt/var control algorithms of the food Load Tap Changer (LTC) transformer and Shunt Capacitor(SC) are proposed for distribution volt/var regulation. In the existing volt/var control of the distribution substation, the voltage of feeders and var of distribution systems is mainly controlled by the LTC transformer tap position and on/off status of the shunt capacitor. The LTC and shunt capacitor bank has discrete operation characteristics and therefore it is very difficult to control volt/var at the distribution networks within the satisfactory levels. Also there is limitation of the operation times of the LTC and shunt capacitor bank because it is affects on their functional lifetime. The proposed volt/var control algorithm determine an optimal tap position of LTC and on/off status of shunt capacitors at a distribution network with the multiple feeders. The mathematical equations of the proposed method are introduced. Simple case study was performed to verify the effectiveness of the proposed method.

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슈퍼 커패시터를 이용한 직류철도 회생에너지 저장장치 (DC Traction Regenerative Energy Storage Devices using Super-capacitor)

  • 김종윤;정두용;장수진;이병국;원충연
    • 전력전자학회논문지
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    • 제13권4호
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    • pp.247-256
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    • 2008
  • 직류철도의 회생제동 시 발생되는 회생에너지는 급전선로의 직류가선전압의 상승에 의해 시스템의 오동작이나 차량 정류기의 파손, 또는 급전 시스템의 전력변환 장치의 고장을 일으키는 원인이 될 수 있다. 슈퍼 커패시터를 이용한 회생에너지 저장장치는 직류가선전압을 안정화 하게하는 방법이다. 본 논문에서는 슈퍼 커패시터 뱅크를 이용하여 직류철도 시스템의 에너지 저장장치를 구현하였고, 지하철 2호선 N역과 S역의 실측값을 이용하여 가선전압이 전동차에 의한 회생에너지 발생에 따른 동작 특성과 슈퍼 커패시터의 충 방전 특성을 확인하였다. 본 논문을 통하여 직류철도 시스템에 설치된 회생에너지 저장시스템용 슈퍼 커패시터 뱅크의 동작 특성을 알 수 있고, 향 후 직류철도 모든 변전소의 직류 가선전압 실측 데이터를 이용한다면, 특정 직류철도 운행 구간에 대한 회생에너지 저장장치의 운전특성과 슈퍼커패시터의 용량 및 수명 예측으로 가격을 절감 할 수 있고 전체 시스템의 안정도 와 신뢰성을 향상시킬 수 있다.

LC공진을 이용한 원격측정용 압력센서의 제작 및 실험 (A Telemetry Silicon Pressure Sensor of LC Resonance Type)

  • 김학진;김순영;양상식
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2001년도 하계학술대회 논문집 C
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    • pp.1872-1874
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    • 2001
  • This paper presents an implantable telemetry LC resonance-type pressure sensor to measure the cerebral ventricle pressure. The sensor consists of an inductor and a capacitor. The LC resonant circuit consists of the sensor and an external antenna coil that are coupled magnetically. The resonance frequency of the circuit decreases as the applied pressure increases the capacitance of the sensor. The sensor is designed in consideration of the biocompatibility and long lifetime for continuous monitoring of the ventricle pressure. The sensor is simple to fabricate and small in comparison with others reported previously. The inductor is fabricated by electroplating and the variable capacitor is constructed with a flexible p+ diaphragm. Also, the deflection of the diaphragm, the variation of the capacitance and the resonance frequency are analyzed and calculated.

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질화된 MOS 커패시터의 C-T 특성 (C-T Characteristics of Nitridized MOS Capacitor)

  • 장의구;최원은;서용진;최현식;유석빈
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1988년도 전기.전자공학 학술대회 논문집
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    • pp.788-791
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    • 1988
  • The C-T characteristics of nitridized MOS capacitor have been studied. The generation lifetimes were calculated using C-T transient response ans found to vary as sample condition. This is due to the non-uniformity of fast surface state. Also, This experimental curves were different from theoretical curves. The result suggests that the change in material structure (from SiO2 to Si-N-O) is important in improving minority carrier lifetime.

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