• Title/Summary/Keyword: $SF_6$ Analysis

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The Physicochemical and Quality Properties of the Bread Added with Soy Fiber Powder (콩식이섬유를 첨가한 식빵의 이화학적 및 품질 특성)

  • Lee, Myung-Ho;Byun, Jong-Beom;Kim, Sun-Kyung;Choi, Young-Sim
    • Culinary science and hospitality research
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    • v.18 no.1
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    • pp.1-14
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    • 2012
  • This study examines the physiochemical and quality properties of the bread added with soy fiber powder to promote the intake of soy fiber. For this study, the powder for making bread was mixed with soy fiber, wheat flour and SF-1450 and SF-1260 at the ratio of 0~12% each. The ratios of the edible fiber contained in the soy fiber power samples were 72.0% in the SF-1450 sample and 67.8% in the SF-1260 sample. The mixograph characteristics tended to be conspicuons in proportion to the amount of the soy fiber added at midline peak height, width at peak and, width at 8.00. The specific volume of the bread tended to decrease significantly as the amount of the soy fiber increased from 2 to 12%. In terms of crust chromaticity change, L-value increased more significantly in the samples added with 4 to 12% than the control. For a-value, SF-1450 in the samples with 6 to 12% and SF-1260 in the samples with 8 to 12% more significantly decreased than the control. For such characteristics of texture as hardness, SF-1450 in the samples with 10 to 12% and SF-1260 in the samples with 6 to 12% increased more than the control. As discussed above, the sensual characteristics of the white pan bread with soy fiber added tended to be worse as the amount of the additive increased, compared with the control samples. Summing up the results of the physico-chemical analysis and the overall acceptability, those samples with 2~4% of SF-1450 and 2% of SF-1260 were found excellent.

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Circuit Interruption Performance Evaluation of $SF_6$ GIS Based Results of Cold Flow and Electrical Field Analysis ($SF_6$ 가스절연개폐기의 냉가스유동해석과 전계해석을 기초로 한 차단성능평가)

  • Bae, Dong-Jin;Song, Tae-Hun;Choi, Young-Chan;Lee, Ki-Ju;Kim, Ik-Mo;Kang, J.H.
    • Proceedings of the KIEE Conference
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    • 1999.07a
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    • pp.89-91
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    • 1999
  • The performance of circuit interruption of $SF_6$ puffer cylinder type gas circuit breaker(GCB) has been evaluated from the results of electrical insulation strength which is depend on material property, such as $SF_6$ gas density in circuit breaker tank. In order to determine circuit breaker dimension in the safety criteria. electrical field analysis has been done by finite element method. Gas density of concerned area in the circuit breaker has been calculated. In order to predict small current break performance, Electrical field analysis result must be calculated based the results of density from cold flow dynamics. The proposed method has been carried out and evaluated for 362kV class high voltage GIS.

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Characteristics of Partial Discharge Under HVDC in SF6 Gas (SF6 가스 중 직류 고전압 하에서 부분방전 특성)

  • Kim, Min-Su;Kim, Sun-Jae;Jeong, Gi-Woo;Jo, Hyang-Eun;Kil, Gyung-Suk
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.27 no.4
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    • pp.238-243
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    • 2014
  • This paper dealt with the measurement and analysis of partial discharge (PD) under high voltage direct current (HVDC) in SF6 gas. Electrode systems such as a protrusion on conductor (POC), a protrusion on enclosure (POE), a crack on epoxy plate and a free particle (FP) were fabricated to simulate the insulation defects. The analysis system was designed with a Time-Frequency (T-F) map algorithm programed based on LabVIEW. This can arrange the acquired PD pulses into frequency and time domain. A HVDC power source is composed of a transformer (220 V/50 kV), a diode (100 kV) and a capacitor (50 kV, 0.5 ${\mu}F$). The gap between the electrodes is 3 mm, and the $SF_6$ gas was set at 5 bar. PD pulses were detected by a 50 ${\Omega}$ non-inductive resistor. In the analysis, PD pulses were distributed below 0.5 MHz and 20 ns ~ 35 ns for the POC, 0.7 MHz ~ 1.7 MHz, below 0.6 MHz and 10 ns ~ 40 ns and 60 ns ~125 ns for the POE, below 0.1 MHz and 135 ns ~ 215 ns for the crack, and below 1.6 MHz and 250 ns for the FP.

The Dependence on the Gas Pressure in SF6 Molecular Gas (SF6분자가스의 압력 의존도)

  • Jeon, Byung-Hoon
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.20 no.9
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    • pp.816-820
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    • 2007
  • We measured the electron drift velocity, W, in 0.5% $SF_6-Ar$ mixture over the E/N range from 30 Td to 300 Td and gas pressure range from 0.1 to 0.5 Torr by the double shutter drift tube with a variable drift distance, and calculated over the same E/N and gas pressure range by using the two-term approximation of the Boltzmann equation. The measured and calculated values at different gas pressure at each E/N was appreciable dependence in the results on the gas pressure.

Analysis of Thermal Recovery Characteristics for Nozzle of SF6 GCB Considering Nozzle Ablation (노즐용삭을 고려한 SF6 가스차단기 노즐의 열적회복특성 해석)

  • Lee Byeong-Yoon;Song Ki-Dong;Chong Jin-Kyo;Park Kyong-Yop
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.54 no.2
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    • pp.76-82
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    • 2005
  • In this paper, a method for analyzing the thermal recovery characteristics of the nozzle of gas circuit breaker was described. In order to obtain thermal recovery characteristics, the transient simulation of SF6 arc plasma within the nozzle was carried out. In particular, the nozzle ablation was taken into account by simultaneously solving the PTFE concentration equation with the governing equations such as continuity, momentum and energy equation. After that, post arc current calculation was performed with the rate of rise of recovery voltage changed. From the calculated post arc current, it was possible to suggest the thermal recovery characteristics of the nozzle of gas circuit breaker.

The analysis of dependence on the gas number density in $SF_{6}$-Ar mixtures ($SF_{6}$-Ar혼합가스에서의 압력 의존도 해석)

  • 전병훈;하성철
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.07a
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    • pp.248-251
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    • 2002
  • We measured the electron drift velocity, W, in 0.5% $SF_{6}$-Ar mixture over the E/N range from 30 Td to 300 Td and gas pressure range from 0.1 to 8 Torr by the double shutter drift tube with a variable drift distance. This coefficient in the mixture was calculated over the same E/N and gas pressure range by using the two-term approximation of the Boltzmann equation. And the measured and calculated values at different gas number density at each E/N was appreciable dependence in the results on the gas number density,

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A INSULATING DESIGN OF $SF_6$ GAS SEALING END OF CONDENSER CONE TYPE USED FOR 345KV OF CABLE (콘덴서 콘 방식의 345KV OF 케이블용 $SF_6$ 가스중 종단접속함의 절연 설계)

  • Kim, H.J.;Lee, S.C.;Oh, O.J.;Lee, H.S.
    • Proceedings of the KIEE Conference
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    • 1994.07b
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    • pp.1553-1555
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    • 1994
  • In this paper, we describes the research in condenser cone of $SF_6$ gas sealing end for 345KV oil-filled cable. The designed of condenser cone based on the results electric field analysis by electrostatics theory ana FEM. As a results. we have been designed the condenser cone and the inner insulation part of $SF_6$ seating end, the width and length, the number of condenser, the length of stress relief slope, the total length of condenser cone.

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Reliability for SF6 gas load break switch of distribution system (배전선로용 가스절연부하개폐기의 신뢰성 향상책)

  • Park, Seung-Jae;Heo, Jong-Chul;Shin, Young-June;Kang, Young-Sik;Koh, Heui-Seog
    • Proceedings of the KIEE Conference
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    • 2003.07a
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    • pp.452-454
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    • 2003
  • $SF_6$ gas has been increasingly used as the insulating and arc-suppressing medium in switchgears which are used as the protection devices of power system. Nowadays, most of power companies adopted the $SF_6$ gas-type load break switch for increasing the reliability of distribution network by its superior durability against external environmental condition, in substitution for air-type and oil-type switches. But, it is important to establish the general estimation process for the testing and estimation for long-term reliability. Accordingly, this paper presents the reliability testing method for $SF_6$ gas load break switch which is based on the analysis of the failure mode and the statistics.

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A study on the repeated breakdown field strength of compressed $SF_{6}$ in uniform field perturbed by protrusion (교란된 평등전계에서 고기압 $SF_{6}$ 가스의 연속절연 파괴강도에 관한 연구)

  • 이동인
    • 전기의세계
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    • v.29 no.2
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    • pp.129-132
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    • 1980
  • For large gas-insulated systems, the conductor utilized possess some degree of surface roughness which locally enhances the applied field at highpressure in $SF_{6}$. In order to investigate the effect of field enhancement on the breakdown field strength, the spheric protrusion was employed which gives a quantitative analysis on field enhancement. For further investigations on the breakdown level and polarity effect in $SF_{6}$, the repeated breakdown tests were performed with d.c. voltage at pressures up to about 4 bar. The experimental results show that the breakdown level does vary noticeably due to successive voltage applications and the breakdown field strength measured for a test gap with the cathode protrusion is markedly lower than that determined from the identical anode protrusion.

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Interrupting Performance of 7.2kV $SF_6$ Gas Electromagnetic Contactor Using Rotary Arc Principle (7.2kV급 로타리아크 소호방식을 이용한 $SF_6$가스 전자접촉기의 차단특성)

  • Chang, K.C.;Chong, J.K.;Shin, Y.J.;Kim, J.K.;Kim, G.S.
    • Proceedings of the KIEE Conference
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    • 1996.07a
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    • pp.77-79
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    • 1996
  • The model interrupters of $SF_6$ gas electromagnetic contactor whose ratings are 7.2kV, 4.0kA have been designed and manufactured on the basis of theoretical and computational analysis for its development. The eddy current analysis, the magnetic field analysis and the calculation of the rotational force on arcs have been conducted using FLUX2D package. The short circuit current interrupting tests have been conducted for the model interrupters using the simplified synthetic testing facility in KERI. The results show that the model interrupters have sufficient interrupting capability and the new design concept is prefer for good interrupting performance.

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