• 제목/요약/키워드: On-current

검색결과 53,517건 처리시간 0.07초

해양 조류발전단지 타당성 조사시 발전용량 산출방법에 관한 연구 (Study on Extractable power capacity of Tidal current power farm in the Feasibility investigation)

  • 조철희;김도엽;채광수;임진영
    • 한국신재생에너지학회:학술대회논문집
    • /
    • 한국신재생에너지학회 2010년도 추계학술대회 초록집
    • /
    • pp.169.1-169.1
    • /
    • 2010
  • Due to global warming, the need to secure an alternative resource has become the international issue. Not like other renewable energy sources, TCP is the high reliable and predictable and continuous energy source as the current pattern and speed can be predicted throughout the year. Having very strong tidal current speeds, there are many suitable site for the application of TCP (Tidal Current Power) on the west and south coastal region in Korea. The maximum current speed in the south is recorded up to 6.5m/s. Due to the high tidal current speed on the west coast of Korea, numerous tidal current projects are being planned. To extract a significant quantity of power, a tidal current farm with number of devices is required in the ocean. However, it is important to estimate the potential quantity of energy in the area. Also the realistic quantity that can be extracted is to be investigated. Based on the estimated energy production considering the number of devices and the interactional effects, system type, the water depth and etc., the cost of the development and the benefit from SMP can be estimated. The feasibility study for the 200MW tidal in Incheon, Korea has been performed recently. Based on the actual feasibility study, the procedure and the key points for the application of tidal current power farm are introduced in the paper.

  • PDF

직렬 연결된 두 코일과 YBCO Coated Conductor로 구성된 초전도 전류제한기의 권선방향과 권선 비에 따른 전류제한 특성 분석 (Analysis on Current Limiting Characteristics of the SFCL with Magnetically Coupled Two Coils and YBCO Coated Conductor Due to the Winding Direction and the Turn Number' Ratio Between Two Coils)

  • 이동혁;두호익;김용진;한병성;한상철;이정필
    • 한국전기전자재료학회논문지
    • /
    • 제24권1호
    • /
    • pp.52-56
    • /
    • 2011
  • The ongoing Superconducting Fault Current Limiter(SFCL) development mainly has focused on the application of commercializaton and power system through combining with normal-conducting device, moving away from current-limiting method, which is solely dependant on the existing superconductor. Compared to the structural development above, on the other hand, the research on applying superconducting current-limiting element to SFCL, the heart of SFCL, still has a lot left to do, apart form traditional resistive type SFCL. In this study, we looked into the current limiting characteristic of SFCL using core and coil. YBCO coated conductor with stainless steel stabilizer layer was verified by the excellent of current-limiting element of the resistive type SFCL that has a high Jc and index as well as being superior in mechanical property. Also, we study temperature characteristics and resistance characteristics, max voltage, response time and current-limiting ability that can be an indicator as current-limiting element while applying to superconducting current-limiting element caused by variation of winding direction, winding ratio of SFCL using core and coil.

3가크롬 도금욕에서 펄스도금조건이 전류효율에 미치는 영향 (The Effect of Pulse Plating on the Current Efficiency in Trivalent Chromium Bath)

  • 황경진;안종관;이만승;오영주
    • 한국표면공학회지
    • /
    • 제36권2호
    • /
    • pp.161-167
    • /
    • 2003
  • In order to investigate the effects of pulse plating conditions on the electrodeposition of trivalent chromium, electroplating experiments from bath with low concentration of trivalent chromium were performed. The variation of current efficiency of chromium electroplating with the electroplating conditions was explained. The maximum current efficiency of pulse plating is 6.4 times as high as that of direct plating at the same mean current density The nodular size increased with pulse plating time and the pulse frequency.

Switching current density for spin transfer torque magnetic random access memory with Dzaloshinskii-Moriya Interaction

  • Song, Kyungmi;Lee, Kyung-Jin
    • 한국자기학회:학술대회 개요집
    • /
    • 한국자기학회 2015년도 임시총회 및 하계학술연구발표회
    • /
    • pp.78-79
    • /
    • 2015
  • We investigate the switching current for various cell diameters and DM interaction. We find that the current density for switching can depend strongly on the cell size when the switching is governed by the domain wall motion. Moreover the switching current density is also strongly influenced by DM interaction. In the presentation, we will discuss the effect of domain wall formation and more various DMI constant on the switching current desity in detail.

  • PDF

순환전류제어형 싸이크로콘버터에서 순환전류의 영향 (Effects of Circulating current on the controlled Circulating current Cycloconverter)

  • 고석진;이규종;성세진
    • 대한전기학회:학술대회논문집
    • /
    • 대한전기학회 1988년도 전기.전자공학 학술대회 논문집
    • /
    • pp.140-143
    • /
    • 1988
  • In this study, so called high frequency cycloconverter which converts commercial so power source directly to high frequency power source is proposed. In this system, the circulating current play very important role. Its state and magnitude effects on system characteristics. This paper deals with the control method of the circulating current and side band component analysis of high frequency side current which is produced by it.

  • PDF

최종체절구간에서 유속변화에 관한 연구 (A Study on the Current Change in Final Closing Section)

  • 신문섭;유시흥;이용래;권철휘;최용규
    • 한국농공학회:학술대회논문집
    • /
    • 한국농공학회 1999년도 Proceedings of the 1999 Annual Conference The Korean Society of Agricutural Engineers
    • /
    • pp.181-184
    • /
    • 1999
  • The purpose of this study is to find on the Current Change and Residual current in Final closing section of Seamangum the sea dike . The M2 current was calculated in two case of the two and three point Final closing section. The residual currents are calculated diagnositically from the observed water temperature and salinity data and wind data and tidal residual current.

  • PDF

다상 동기 벅 컨버터의 Passive Current Sharing 특성 (Passive Current Sharing Characteristics of Multi-Phase Synchronous Buck Converter)

  • 김정훈;조경식;정세교
    • 전력전자학회:학술대회논문집
    • /
    • 전력전자학회 2007년도 하계학술대회 논문집
    • /
    • pp.175-177
    • /
    • 2007
  • An analysis on a passive current sharing characteristics of a multi-phase synchronous buck converter is presented. The passive current sharing method is simple but its characteristics depend on the converter equivalent resistance and PWM uniformity. In this paper, the load sharing and power consumption of the passive current sharing system for the converter equivalent resistance and duty ratio inequalities are investigated through the simulation and experiment.

  • PDF

전류 감쇠 조정 회로에서의 정밀도 향상 기술 (Accuracy Enhancement Technique in the Current-Attenuator Circuit)

  • 김성권
    • 조명전기설비학회논문지
    • /
    • 제19권8호
    • /
    • pp.116-121
    • /
    • 2005
  • 전류모드 아날로그 회로를 이용하여 FIR(Finite Impulse Response) 필터를 설계하는 경우에 tap coefficient와 전류모드 FFT(Fast Fourier Transform) LSI의 회전인자(twiddle factor)를 실현시키기 위해서는 높은 정밀도를 갖는 전류 감쇠 회로가 필요하게 된다. 본 논문은 전류 모드 신호처리 기술에서 전류감쇠 회로의 감쇠 정밀도를 향상시킬 수 있는 기술을 소개하고자한다. 먼저 게이트 길이 비율을 조정하는(gate-ratioed) Current Mirror 회로를 사용하는 기존의 전류 감쇠 조정회로에 있어서의 DC offset 전류 에러에 대하여 분석하였으며, 다음으로 DC offset 전류 에러를 제거할 수 있는 전류감쇠 회로를 제안하였다. 회로 구성은 입력 전류를 1/N로 감쇠시킬 수 있도록 N개의 Current Mirror를 병렬로 연결하는 기본 구성을 하였으며, Kirchhoff 전류 법칙에 근거하여, 전류 감쇠가 결정되도록 설계하였다. 또한 Current Mirror 회로에서, 정전류원의 사용을 줄일 수 있는 회로설계를 제안하였다. 제안된 전류 감쇠 회로에서 정밀도는 Current Mirror의 ac 이득 에러에 의하여 제한되며 High Swing Current Mirror를 기본 Current Mirror로 사용한 경우에, 최대 정밀도는 이론상 입력 전류의 -80[dB]까지 실현가능하다.

전자장 해석 프로그램을 이용한 와전류 문제의 해석 및 이해 (Analysis and Understanding of Eddy Current Problem using electromagnetic field Packeg)

  • 임건규;이향범
    • 대한전기학회:학술대회논문집
    • /
    • 대한전기학회 2006년도 제37회 하계학술대회 논문집 D
    • /
    • pp.2203-2204
    • /
    • 2006
  • When the coil with alternating current approaches to the conductor the eddy current flows in conductor. Eddy current is concentrated on the conductor surface and decrescent because of skin effet.. In this paper investigated eddy current characteristic that is happened in conductor. Analyzed characteristic using electromagnetic field finite element analysis program that is commercialized to analyze value of eddy current and penetration depth. Analyzed creation value of eddy current and penetration depth in conductor that change operation frequency and the material of conductor, coil outside diameter, inside diameter, position, type of conductor from analyzed eddy current characteristic. The results. using distribution of eddy current and penetration depth data is that will help to forecast ECT(Eddy Current Testing), Eddy current application and use field, eddy current loss.

  • PDF

전자장 해석 프로그램을 이용한 와전류 문제의 해석 및 이해 (Analysis and Understanding of Eddy Current Problem using electromagnetic field Packeg)

  • 임건규;이향범
    • 대한전기학회:학술대회논문집
    • /
    • 대한전기학회 2006년도 제37회 하계학술대회 논문집 A
    • /
    • pp.571-572
    • /
    • 2006
  • When the coil with alternating current approaches to the conductor the eddy current flows in conductor. Eddy current is concentrated on the conductor surface and decrescent because of skin effet.. In this paper investigated eddy current characteristic that is happened in conductor. Analyzed characteristic using electromagnetic field finite element analysis program that is commercialized to analyze value of eddy current and penetration depth. Analyzed creation value of eddy current and penetration depth in conductor that change operation frequency and the material of conductor, coil outside diameter, inside diameter, position, type of conductor from analyzed eddy current characteristic. The results, using distribution of eddy current and penetration depth data is that will help to forecast ECT(Eddy Current Testing), Eddy current application and use field, eddy current loss.

  • PDF