• 제목/요약/키워드: Electrical discharging technique

검색결과 22건 처리시간 0.023초

Expeditious Full Discharging Method without Voltage Rebound Issue for Safe Battery Recycling

  • Ji-Su Woo;Hong-Geun Lee;Geun-Ha Hwang;Keun-Ho Heo;Yu-Chan Hwang;Won-Jin Kwak
    • Journal of Electrochemical Science and Technology
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    • 제15권4호
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    • pp.459-465
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    • 2024
  • To achieve recycling without safety hazards by explosion of spent batteries, an efficient full discharging procedure is required to stabilize the batteries before recycling. However, typical salt solution discharging technique has environmental pollution, inefficiency, and safety issues due to wastewater emission, slow discharging rate, and severe voltage rebound. Electrical discharging techniques can be applied to overcome these problems, but the typical constant-current and constantcurrent constant-voltage modes have a trade-off relationship between discharge time and voltage rebound. In this study, we propose reverse voltage mode as an expeditious and safe electrical discharging protocol that effectively addresses the tradeoff between discharging time and voltage rebound. The proposed reverse voltage mode for full discharging method was proven to be effective regardless of the electrode crystal structure or the battery form factor. This result is expected to present new methodology for pre-stabilization of spent batteries for more eco-friendly and stable recycling.

Step Pulse Shaping Technique for Nd:YAG Laser Using a Multi-Switching Method

  • Kwak, Su-Young;Park, Jin-Young;Kim, Su-Weon;Min, Byoung-dae;Chung, Hyun-ju;Kim, Hee-je
    • KIEE International Transactions on Electrophysics and Applications
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    • 제4C권2호
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    • pp.55-59
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    • 2004
  • Throughout manufacturing processes, pulse shaping is required for material processing and it is regarded as an important (actor according to the specific characteristics of materials. Therefore, this study suggests a highly appropriate pulse shaping technique using a multi-switching method. This is a pulse superposition method in which one flash lamp can consecutively turn on by the double switching of the discharging system. It is possible to construct a variety of pulse shapes and pulse widths by the consecutive trigger of the silicon-controlled rectifiers (SCR) of a PIC (program integrated circuit) one-chip microprocessor. The use of this technique can provide a number of advantages to people who require suitable pulse shaping for particular applications such as welding, cutting, and drilling.

플라잉 커패시터 멀티-레벨 인버터의 플라잉 커패시터 전압 균형을 위한 캐리어 로테이션 기법 (A Carrier-Rotation Strategy for Voltage Balancing of Flying Capacitors in Flying Capacitor Multi-level Inverter)

  • 이원교;강대욱;김태진;현동석
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2003년도 춘계전력전자학술대회 논문집(2)
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    • pp.630-634
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    • 2003
  • This paper proposes a Carrier-Rotation PWM technique that is new solution for the voltage unbalancing problem of flying capacitors in the Flying Capacitor Multi-level Inverter (FCMI).The proposed PWM technique equalizes the utilization of phase leg voltage redundancies corresponding to the charging and the discharging state of flying capacitors during one switching period of all the switches. it also has the same switch utilization and the reduced harmonics of output voltage. Hence, it is more suitable for the FCMI compared with the conventional solutions. Experimental results on the laboratory prototype flying capacitor 3-level inverter confirm the validity of the proposed PWM technique.

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Analysis and Implementation of a DC-DC Converter for Hybrid Power Supplies Systems

  • Yang, Lung-Sheng;Lin, Chia-Ching
    • Journal of Power Electronics
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    • 제15권6호
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    • pp.1438-1445
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    • 2015
  • A new DC-DC power converter is researched for renewable energy and battery hybrid power supplies systems in this paper. At the charging mode, a renewable energy source provides energy to charge a battery via the proposed converter. The operating principle of the proposed converter is the same as the conventional DC-DC buck converter. At the discharging mode, the battery releases its energy to the DC bus via the proposed converter. The proposed converter is a non-isolated high step-up DC-DC converter. The coupled-inductor technique is used to achieve a high step-up voltage gain by adjusting the turns ratio. Moreover, the leakage-inductor energies of the primary and secondary windings can be recycled. Thus, the conversion efficiency can be improved. Therefore, only one power converter is utilized at the charging or discharging modes. Finally, a prototype circuit is implemented to verify the performance of the proposed converter.

광섬유 센서를 이용한 변압기 절연유의 열화 진단 (Diagnosis for Degradation of Transformer Oil by an Optical Fiber Sensor)

  • 이수묵;김태영;서광석;성만영
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2000년도 하계학술대회 논문집 C
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    • pp.1563-1565
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    • 2000
  • This paper presents the preliminary results on the application of optical fiber sensor(OFS) for the diagnosis of degradation in the transformer oil. An OFS system using a Mach-Zehnder interferometry technique was built to detect attenuation of acoustic signal produced by discharging. With increasing the number of discharging in the insulation oil, the attenuation of acoustic signal became greater. A strong correlation between electrical and acoustic signal intensities from discharge generated in the transformer oil was confirmed by the results reported here.

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무성방전 오조나이저의 성능개선을 위한 2중 디지털 제어기의 설계 (Design of Double Digital Controller to Improve Performance for the Silent Discharging Ozonizer)

  • 박지호;김동완;우성훈;노인배;우정인
    • 전기학회논문지P
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    • 제55권1호
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    • pp.13-20
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    • 2006
  • In this paper, a control method of ozone generator for a tiny deodorizer is proposed, and also a cooling technique is described which is cooling down the flowing air gap into a silent discharger to $2[^{\circ}C]$ to generate ozone of high density and diffusing power. As the digital control system for this method, a double feedback loop is designed which detects the voltage and current of equivalent capacitor of the discharger and compensates for the poor power waveform caused by the noise at high discharging frequency. During the plant modeling of this system, computing time factor is considered as a unique parameter of the power system to improve the respond characteristics with regard to fluctuating load and to replenish the computing time delay of the controller. Through the experiment, sinusoidal input current for discharger can be acquired and all the effectiveness of this accurate control system over unstable ozone discharger are proved.

개질된 전력용 케이블절연체의 부분방전 특성 해석 (PD Characteristics Analysis of Improved Insulating Materials for Power Cables)

  • 송일근;곽희로
    • 한국조명전기설비학회지:조명전기설비
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    • 제11권5호
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    • pp.93-102
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    • 1997
  • 본 논문은 성능이 우수한 전력케이블용 절연재료 개발에 대한 기초자료를 얻기 위한 연구로서, 초음파 센서를 사용하여 폴리에틸렌의 부분방전 특성을 측정하고 측정된 신호의 정량화를 시도하여 폴리에틸렌에서 발생되는 부분방전을 억제시킬 수 있는 방안에 관한 연구를 수행하였다. 이러한 결과로부터 기본 수지인 저밀도 폴리에틸렌을 적당히 개질하면 폴리에틸렌의 부분방전이 억제될 수 있음을 알았고, 이를 검증하기 위하여 폴리에틸렌을 아크릴산으로 개질하여 아크릴산 그라프트 폴리에틸렌을 제조하였으며, 이에 대한 부분방전 특성을 평가하였다. 평가결과, 본 연구에서는 아크릴산이 0.03 wt〔%〕정도 그라프트되면 폴리에틸렌의 부분방전이 크게 억제됨을 발견하였다. 이러한 결과로부터 폴리에틸렌을 적당한 화학성분으로 개질하면 폴리에틸렌의 부분방전이 크게 억제되었다.

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A study on charging and electrical stability characteristics with no-insulation and metal insulation in form of racetrack type coils

  • Quach, Huu Luong;Kim, Ho Min
    • 한국초전도ㆍ저온공학회논문지
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    • 제22권3호
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    • pp.13-19
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    • 2020
  • This study presents the experiment and simulation results on the magnetic field response and electrical stability behaviors of no-insulation (NI) and metal insulation with stainless steel tape (MI-SS) which wound in form of racetrack type coils. First of all, the structural design of the racetrack type bobbin was shown along with its parameters. Then, the current-voltage tests were carried out to measure the critical current of both test coils. Also, the sudden discharging and charging tests were performed in the steady state to estimate the decay field time and magnetic field response, respectively. Finally, the overcurrent tests were conducted in the transient state to investigate the electrical stability of these test coils. Based on the experimental results, the contact surface resistances were calculated and applied to the field coils (FCs) of 10-MW-class second generation high temperature superconducting generator (2G HTSG) used in wind offshore environment. The charging delay time and electrical stability for NI and MI-SS HTS FCs of 10-MW-class 2G HTSG are analyzed by the equivalent circuit model and the key parameters which were obtained from the electromagnetic finite element analysis results.

CNT를 이용한 Supercapacitor의 충.방전 특성 (The Effect of CNT Electrode on the Charging and Discharging Characteristics of Supercapacitor)

  • 허근;명성재;이용현;전명표;조정호;김병익;심광보
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2007년도 추계학술대회 논문집
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    • pp.275-275
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    • 2007
  • Two sorts of electrode composed of Sulpur/CNT/PVDF and Silver/CNT/PVDF were prepared by in situ chemical method and their electrochemical performance were evaluated by using cyclic voltammetry, impedance measurement and constant-current charge/discharge cycling technique. Also, composite electrodes were characterized by FE-SEM and BET. Raw materials such as CNT/Silver and CNT/Sulfur were mixed in ethanol, dried. These mixed materials were heated at 900 and $320^{\circ}C$ for 2hr, respectively in order to enhance contact among CNT electrodes. Electric double layer capacitor cells were fabricated using these mixed powder with polymer of PVDF. For the charging and discharging characteristics measured at scan rate of 1 mA/s, Supercapacitor of Sulphur-CNT-PVDF electrode showed a better performance than that of Ag-CNT-PVDF, which seems to be related with lower contact resistance of Sulphur-CNT-PVDF electrode.

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직류 도시철도 시스템 에너지 효율 향상 및 안정화를 위한 슈퍼커패시터 에너지 저장장치 활용 방안 연구 (Supercapacitor Applications for System Stabilization and Efficiency Improvement on DC Railway System)

  • 송지영;이계병;이한상;장길수;권세혁;이장무;이한민;김길동
    • 전기전자학회논문지
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    • 제13권1호
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    • pp.49-56
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    • 2009
  • 본 논문에서는 철도 시스템에 에너지 저장장치를 도입하여 충 방전을 통한 가선전압의 안정화와 회생에너지의 효율적인 사용을 모의하였다. 이를 위해 간단한 철도 모델과 적절한 제어기법을 제시하였다. 가선전압의 영역을 제어가 필요한 두 영역과 정상운전 영역으로 구분하여 전압제어를 하고, 슈퍼커패시터의 전류제한을 충족시키기 위하여 전류제어를 병행하였다. 이를 바탕으로 에너지의 저장, 방출을 시뮬레이션을 통하여 확인하였고, 철도의 운전 상태에 따라 에너지 충 방전을 통한 에너지 효율을 살펴보았다.

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