• 제목/요약/키워드: Reactor tap

검색결과 30건 처리시간 0.023초

리액터 탭 절환에 의한 유도전동기의 기동 특성 (Starting Characterization of Induction Motor using Reactor Tap Change)

  • 김종겸
    • 전기학회논문지P
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    • 제63권1호
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    • pp.24-28
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    • 2014
  • An induction motor is most widely used to obtain driving force in the industrial field. The induction motor is generated a high current at starting. A starting current is often more than five times of rated current. A high starting current can cause problems such as voltage drop in the power system. In order to solve these problems, a reactor starting method has been widely applied in a large motor capacity. There are differences in the operating characteristics of induction motor corresponding the switching time of reactor tap. In this study, I analyzed that current, torque, power of induction motor are different from changing time and tap setting values of reactor tap.

2-3 ? 변환방식에 의한 새로운 고조파 저감형 컨버어터 시스템 (A New Converter System of Reducing Harmonics by 2-3 Switching Taps on Interphase Reactor)

  • Lee, Seong-Ryong
    • 대한전자공학회논문지
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    • 제24권4호
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    • pp.658-666
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    • 1987
  • In this paper, a new mehtod of reducing harmonics that involved in input AC line currents or in output DC voltage of the converter system is presented. which is due mainly to the quipment of 2-3 switching taps on interphase reactor. In case that the 3 tap method is applicable to conventional 12 pulse converter, it could not bring to an effect of reducing harmonics under firing angle 15\ulcorner To solve these problems, 24 pulse or 36 pulse converter is controlled by microprocessor. The former is performed in 2 tap method when \ulcorneris less than 15\ulcorner the latter in 3 tap method when it is more then 15\ulcorner Therefore the originality of this paper liea in microprocessor based equipment of the 2-3 switching taps on interphase reactor. I applied this method to the 12 pulse converter, and proved validity of that theoretically and experimentally.

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상간리액터의 2-4? 변환 방식에 의한 콘버어터 입력 전류의 고조파 저감에 관한 연구 (A new Method for Reducing Harmonics in Input AC Line Currents of Converter by 2-4 Switching taps on Interphase Reactor)

  • 유철로;이공희;이성룡
    • 대한전기학회논문지
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    • 제37권1호
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    • pp.25-32
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    • 1988
  • In this paper, a new method for reducing harmonics in input AC line currents of converter is presented, which is due mainly to the equipment of 2-4 switching taps on interphase reactor. When this method is applicable to conventional 12 pulse converter, the 24 pulse converter, the 24 pulse or 48 pulse converter is controlled by firing angles. The former is performe in 2 tap method when less than 15 degrees, and the letter in 4tap method when more than 15 degrees. Therefore, the proposed method has the advantages of reducing harmonics in full range of control angle and comparison with the conventional 3 tap method. We proved the validity of that theoretically and experimentally.

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분기관 진동에 의한 피로파괴 (Vibration Related Branch Line Fatigue Failure)

  • 전형식;박보용
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 1990년도 추계학술대회논문집; 한양대학교, 서울; 24 Nov. 1990
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    • pp.113-124
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    • 1990
  • Tap lines are small branch piping generally less than two inches in diameter. They typically branch off of header piping having a much larger diameter. An example of a common tap line is a 3/4 inch size high point vent or low point drain. Most tap lines have at least one valve near the header tap connection to provide isolation. Two valves are often required for double isolation. A light water reactor(LWR) nuclear power plant will have several hundred tap lines. These lines come in many sizes and shapes and serve numerous functions. A single process piping valve may have three different tap lines associated with it (figure 1). Table 1 delineates the different categories of tap lines. Vibration failures of tap lines are a common occurrence in all industrial plants including nuclear and fossil power plants. These types of failures constitute a significant percentage of all piping related failures. An unscheduled plant shutdown or outage resulting from the failure of a tap line decreases plant reliability and may have a detrimental effect on plant safety. Most tap line vibration failures can be avoided through the use of appropriate routing and support techniques. Standardized designs can be developed for use in a myriad of applications. These designs will not only minimize failures but will also reduce the necessary analysis and installation efforts.

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입력 변압기 없는 3상 멀티-펄스 콘버터의 고조파 저감 (Harmonic Reduction of Three Phase Multi-Pulse Converter Circuit without Input Transformer)

  • 박현철;김영민;황종선;김종만
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2002년도 춘계학술대회 논문집 센서 박막재료 반도체재료 기술교육
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    • pp.128-131
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    • 2002
  • In this paper, a new method for reducing harmonic in input AC line currents of converter presents, which is the multi-pulse converter circuit without the input transformer. This system can reduce the harmonic like conventional 12-pulse converter. Both the bridge circuits are controlled with the shifted firing angle and connected 2 tap inter-phase reactor. Using 2 tap changing on inter-phase reactor, the input current is controlled with the different two values in order to make the input current waveform 12 pulses.

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자동 탭 절환 내장형 주상변압기 개발에 관한 연구 (Development Pole Transformer with Automatic Tap Changer)

  • 남궁원;이성우;장문종
    • 조명전기설비학회논문지
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    • 제27권9호
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    • pp.108-113
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    • 2013
  • Change of supply voltage, customer load, output of distributed generation, etc cause voltage change in distribution system. OLTC and SVR are usually used to supply normal voltage at customer. But usage of these devices is inefficient and uneconomical in certain circumstances. To solve this problem, new pole transformer which has automatic tap changer is developed. The transformer changes tap when voltage changes. And it has latch switch and reactor for supplying power without outage. To verify normal operation of tap changer, test is conducted. SVR and 50kVA load is used for test.

마이크로-나노버블 반응조를 이용한 미생물성장 동력학 계수의 추정에 관한 연구 (Estimation of Kinetic Parameters for Biomass Growth Using Micro-nano Bubbles Reactor)

  • 한영립;정병길;정유진;조도현;성낙창
    • 한국환경과학회지
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    • 제19권5호
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    • pp.647-653
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    • 2010
  • The objectives of this research are to evaluate and compare the oxygen transfer coefficients($K_{La}$) in both a general bubbles reactor and a micro-nano bubbles reactor for effective operation in sewage treatment plants, and to understand the effect on microbial kinetic parameters of biomass growth for optimal biological treatment in sewage treatment plants when the micro-nano bubbles reactor is applied. Oxygen transfer coefficients($K_{La}$) of tap water and effluent of primary clarifier were determined. The oxygen transfer coefficients of the tap water for the general bubbles reactor and micro-nano bubbles reactor were found to be 0.28 $hr^{-1}$ and 2.50 $hr^{-1}$, respectively. The oxygen transfer coefficients of the effluent of the primary clarifier for the general bubbles reactor and micro-nano bubbles reactor were found be to 0.15 $hr^{-1}$ and 0.91 $hr^{-1}$, respectively. In order to figure out kinetic parameters of biomass growth for the general bubbles reactor and micro-nano bubbles reactor, oxygen uptake rates(OURs) in the saturated effluent of the primary clarifier were measured with the general bubbles reactor and micro-nano bubbles reactor. The OURs of in the saturated effluent of the primary clarifier with the general bubbles reactor and micro-nano bubbles reactor were 0.0294 mg $O_2/L{\cdot}hr$ and 0.0465 mg $O_2/L{\cdot}hr$, respectively. The higher micro-nano bubbles reactor's oxygen transfer coefficient increases the OURs. In addition, the maximum readily biodegradable substrate utilization rates($K_{ms}$) for the general bubbles reactor and micro-nano bubbles reactor were 3.41 mg COD utilized/mg active VSS day and 7.07 mg COD utilized/mg active VSS day, respectively. The maximum specific biomass growth rates for heterotrophic biomass(${\mu}_{max}$) were calculated by both values of yield for heterotrophic biomass($Y_H$) and the maximum readily biodegradable substrate utilization rates($K_{ms}$). The values of ${\mu}_{max}$ for the general bubbles reactor and micro-nano bubbles reactor were 1.62 $day^{-1}$ and 3.36 $day^{-1}$, respectively. The reported results show that the micro-nano bubbles reactor increased air-liquid contact area. This method could remove dissolved organic matters and nutrients efficiently and effectively.

3상 비대칭 정류회로의 PAM 방식을 이용한 고주파 저감법 (Reducing Harmonics of 3-Phase Asymmctic Recnher Current using a PAM mcthod)

  • 오훈;윤양웅;박현철
    • 한국조명전기설비학회:학술대회논문집
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    • 한국조명전기설비학회 1995년도 추계학술발표회논문집
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    • pp.105-109
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    • 1995
  • In this paper, we persents a new PAM method without the input transformer for reducing harmonics in input AC line currents of converter. This system can reduce the harmonics like conventional 12-pulse converter. the dual bridge circuits are controlled with the shifted firing angle and connected 2 tap interphase reactor. the input current using 2 tap changing on interphase reactor is controlled with the different two values in order to make the input current waveform 12 pulses. The chracteristics of this system were confirmed through the computer simulation and the experiments.

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리액터 탭 설정값에 따른 유도발전기의 돌입전류와 전압강하 분석 (Analysis for the Inrush Current and Voltage Drop of Induction Generator by the Reactor Tap Change)

  • 김종겸
    • 전기학회논문지
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    • 제64권8호
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    • pp.1202-1206
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    • 2015
  • The induction generator has many advantages compared to the synchronous generator in terms of cost and maintenance. So squirrel cage induction generator has been recently supplied in small hydroelectric power station. Squirrel cage induction generator generates a high inrush current at the grid-connection. This high inrush current causes a voltage drop on the grid. In order to increase the supply of the induction generator, it is very important to find the method of reducing inrush current and voltage drop.

수도관의 생물막 형성에 미치는 잔류염소와 파이프 재질의 영향 (Effects of Chlorine Residual and Pipe Material on the Biofilm Formation in Drinking Water Distribution Pipe)

  • 박세근;박재우;성권식;최성찬;김영관
    • 산업기술연구
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    • 제21권B호
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    • pp.11-20
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    • 2001
  • This laboratory study examined the impact of free chlorine residual and pipe material on the formation of biofilm in drinking water distribution pipe surfaces. Result of heterotrophic plate counts(HPC) of the biofilm in the tap water-supplied reactor averaged $2.17{\times}10^5CFU/cm^2$ on PVC and $2.43{\times}10^5CFU/cm^2$ on STS 316, respectively. HPCs on the surface exposed to the tap water containing 0.2mg/L of free chlorinne residual averaged $4.24{\times}10^4CFU/cm^2$ on PVC and $6.54{\times}10^4CFU/cm^2$ on STS 316, respectively. Average of HPC/Total direct counts in the tap water-supplied reactor ranged from 1.08%(PVC) to 1.26%(STS 316) and from 0.38%(PVC) to 0.65%(STS 316) in the reactor supplemented with disinfectant, respectively. No correlation was observed between disinfectant addition and biofilm density. With regard to the biofilm formation, little difference existed between PVC and STS 316. Yellow and red pigmented bacteria were the dominant expressions in bulk fluid, whereas non-pigmented bacteria were found dominant in the biofilm. Pink/red pigmented bacteria were found to be facultative anaerobic, while yellow pigmented bacteria and non-pigmented bacteria were found to be obligate aerobic.

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