• Title/Summary/Keyword: Junction

Search Result 3,315, Processing Time 0.029 seconds

Reduction of Heat Generation from Junction Box in 3 kW Photovoltaic Power Generation System

  • Yun, Jung-Hyun;Sun, Ki-Ju;Cheon, Min-Woo
    • Transactions on Electrical and Electronic Materials
    • /
    • v.17 no.1
    • /
    • pp.21-24
    • /
    • 2016
  • A junction box used in a 3 kW photovoltaic power generation system plays a role in collecting and supplying the direct current voltage produced by photovoltaic modules to an inverter. It is also used for facilitating maintenance checks and protecting the module and inverter by keeping the voltage constant. As for the junction box, using it in a parallel connection creates a difference between the setup modules. In order to compensate, an inverse voltage diode is used. But the high-power created through the solar generator can be delivered to the inverter through the inverter regularly. Therefore, a component can break down due to excess heat. And consequently short circuits and electric leakage occurs. In this study, using a junction box that enabled the bypass of high electric power, it was possible to reduce heat generation by approximately 35℃ when compared to a standard junction box.

Developing of Super Junction MOSFET According to Charge Imbalance Effect (전하 불균형 효과를 고려한 Super Junction MOSFET 개발에 관한 연구)

  • Kang, Ey Goo
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.27 no.10
    • /
    • pp.613-617
    • /
    • 2014
  • This paper was analyzed electrical characteristics of super junction power MOSFET considering to charge imbalance. We extracted optimal design and process parameter at -15% of charge imbalance. Considering extracted design and process parameters, we fabricated super junction MOSFET and analyzed electrical characteristics. We obtained 600~650 V breakdown voltage, $224{\sim}240m{\Omega}$ on resistance. This paper was showed superior on resistance of super junction MOSFET. We can use for automobile industry.

Effect of Bundle Junction Face and Misalignment on the Pressure Drops Across a Randomly Loaded and Aligned 12 Bundles in Candu Fuel Channel

  • H. C. Suk;K. S. Sim;C. H. Chung;Lee, Y. O.
    • Nuclear Engineering and Technology
    • /
    • v.28 no.3
    • /
    • pp.280-289
    • /
    • 1996
  • The pressure drop of twelve fuel bundle string in the CANDU-6 fuel channel is equal to the sum of the eleven junction pressure losses, the bundle string entrance and exit pressure losses, the skin friction pressure loss, and other appendage pressure losses, where the junction loss is dependent on the bundle end faces and angular alignments of the junctions. The results of the single junction pressure drop tests in a short rig show that the most probable pressure drop of the eleven junctions was analytically equal to the eleven times of average pressure drop of all the possible single junction pressure drops, and also that the largest and smallest junction pressure drops across the eleven junctions probably occurred only with BA and BB type junctions, respectively, where A and B denote the bundle end sides with an end-plates on which a company monogram is stamped and unstamped, respectively.

  • PDF

A Study on the Power Loss Simulation of IGBT for HVDC Power Conversion System

  • Cho, Su Eog
    • Journal of the Korean Society of Industry Convergence
    • /
    • v.24 no.4_1
    • /
    • pp.411-419
    • /
    • 2021
  • In this study, IGBT_Total_Loss and DIODE_Total_Loss were used to analyze the slope of the junction temperature for each section for temperature and duty variables in order to simply calculate the junction temperature of the power semiconductor (IGBT). As a result of the calculation, IGBT_Max_Junction_Temp and DIODE_Max_Junction_Temp form a proportional relationship with temperature for each duty. This simulation data shows that the power loss of a power semiconductor is calculated in a complex manner according to the current dependence index, voltage dependence index, and temperature coefficient. By applying the slope for each condition and section, the junction temperature of the power semiconductor can be calculated simply.

A Study on the Correlation between Thoracolumbar Junction and Back-su points(背兪穴), Hwatahyeopcheok points(華他夾脊穴) for Treatment of Low Back Pain (요통 치료를 위한 흉요추 이행부 (Thoracolumbar Junction) 와 배유혈(背兪穴), 화타협척혈(華他夾脊穴)의 상관성 에 관한 연구)

  • Park, Young-Hoi;Keum, Dong-Ho;Kim, Dae-Feel
    • The Journal of Korea CHUNA Manual Medicine
    • /
    • v.5 no.1
    • /
    • pp.77-84
    • /
    • 2004
  • Objectives : This study was designed to investigate the correlation between thoracolumbar junction and back-su points, Hwatahyeopcheok points for treatment of low back pain in the thoracolumbar junction syndrome that was suggested by Maigne R. Method : We Investigate the acupuncture points that was correlated with the location of thoracolumbar junction area. And We tried to find out a common point between thoracolumbar junction and back-su points, Hwatahyeopcheok points for treatment of low back pain. Results and Conclusion : 1. It is considered that these points such as $BL_{20}$, $BL_{21}$, $BL_{22}$, and Hwatahyeopcheok points that are located from 11th thoraic spinous process to 2nd lumbar spinous process are correspond to the thoracolumbar junction area. 2. It is suggested that acupuncture treatment on $BL_{20}$, $BL_{21}$, $BL_{22}$, and Hwatahyeopcheok points can release the tenderness of the muscles, recover autonomic nervous function and release smooth muscles and vascular contraction, so it can treat low back pain caused by thoracolumbar junction.

  • PDF

Mechanism for Gating of Gap Junction Channel. (간극결합채널의 개폐기전)

  • 오승훈
    • Journal of Life Science
    • /
    • v.14 no.5
    • /
    • pp.882-890
    • /
    • 2004
  • Gap junction is a membrane structure facilitating the direct transmission of several ions and small molecules between two cells. It is also called an 'intercellular channel' to distinguish it from other well-known cellular channels (e.g. sodium and potassium channels). Gap junction channels are not passive conduits, rather the ion channels modulated by several stimuli including pH, calcium ion, voltage, and a chemical modification (mainly known as phosphorylation). Among them, the effects of voltage on the gating of gap junction channels have been well studied. Gap junction channels are more sensitive to the transjunctional potential ($V_j$) between two cells rather than the membrane potential($V_m$) between inside and outside the cell. In this review, I will summarize the general properties of gap junction channel and discuss the gating mechanism for the gap channels.

Junction Size Dependence of Magnetic and Magnetotransport Properties in MTJs (자기터널절합에서 자기 및 자기저항의 접합크기 의존성)

  • Sankaranarayanan, V.K.;Hu, Yong-kang;Kim, Cheol-Gi;Kim, Chong-Oh;Lee, Hee-bok
    • Korean Journal of Materials Research
    • /
    • v.13 no.6
    • /
    • pp.369-373
    • /
    • 2003
  • Magneto-optic Kerr Effect(MOKE), AFM and magnetoresistance measurements have been carried out on as-deposited and annealed Magnetic Tunnel Junctions(MTJs) with junction sizes 180, 250, 320 and 380 $\mu\textrm{m}$ in order to investigate the correlation among interlayer exchange coupling, surface roughness and junction size. Relatively irregular variations of coercivity $H_{c}$ (∼17.5 Oe) and interlayer exchange coupling $H_{E}$ (∼17.5 Oe) are observed over the junction in as-deposited sample prepared by DC magnetron sputtering. After annealing at $200^{\circ}C$, $H_{c}$ decreases to 15 Oe, while $H_{ E}$ increases to 20 Oe with smooth local variation. $H_{E}$ shows very good correlation with surface roughness across the junction in agreement with Neel's orange peel coupling. The increasing slope per $\mu\textrm{m}$ of normalized $H_{c}$ and $H_{E}$ are same near junction edge along free-layer direction irrespective of junction size, giving relatively uniform $H_{c}$ and $H_{ E}$ for wider junction size. Thickness profiles of the junctions measured with $\alpha$-step show increasingly flat top surface for larger junctions, indicating better uniformity for large. junctions in agreement with the normalized$ H_{c}$ and H$/_{E}$ curves. TMR ratios also increase with increasing junction size, indicating improvement for larger uniform junctions.

A Study on the Electrical Characteristics according to Growth of Trench SiO2 Inside Super Junction IGBT Pillar (Super Junction IGBT 필러 내부 Trench SiO2성장에 따른 전기적 특성에 관한 연구)

  • Lee, Geon Hee;Ahn, Byoung Sup;Kang, Ey Goo
    • Journal of IKEEE
    • /
    • v.25 no.2
    • /
    • pp.344-349
    • /
    • 2021
  • This paper proposes a structure in which Trench SiO2 is grown inside of Super Junction IGBT P-Pillar. When observing the electric field in 3D, we checked the region where the electric field have not affected inside of the P-Pillar. The pillar region's portion resistance is varied by the breakdown voltage and size of each pillar, which reduces the size by growing SiO2 after trenching has no field effect inside of that. At 4.5kV the same breakdown voltage, it was confirmed that the On-state voltage drop improved by about 58%, 19% compared to Field Stop IGBT and conventional Super Junction IGBT.

A Study on the Charge Balance Characteristics of Super Junction MOSFET with Deep-Trench Technology (Deep-Trench 기술을 적용한 Super Junction MOSFET의 Charge Balance 특성에 관한 연구)

  • Choi, Jong-Mun;Huh, Yoon-Young;Cheong, Heon-Seok;Kang, Ey-Goo
    • Journal of IKEEE
    • /
    • v.25 no.2
    • /
    • pp.356-361
    • /
    • 2021
  • Super Junction structure is the proposed structure to minimize the Trade-off phenomenon of power devices. Super Junction can have On-resistance(Ron) characteristics as less as five times than conventional structure. There are process methods that Multi-Epi and Deep-Trench of Super Junction structure. The reason for this is that Deep-Trench process is known to be a relatively difficult manufacturing method because it is easy to form a P-Pillar by burying impurities on top of a silicon substrate through a Deep-Trench process. However, the structure created by the Deep-Trench process has low On-resistance and high breakdown voltage, showing better efficiency. In this paper, we suggested a novel method in the process and designed structure with Charge Balance theory.