• Title/Summary/Keyword: E-J power

Search Result 823, Processing Time 0.031 seconds

Critical Current Estimation of HTS Magnets by using Field Dependent E-J Relation (전계를 이용한 팬케이크 권선으로 제작되는 마그넷의 임계전류 산정)

  • Kang, Myung-Hun;Koo, Myung-Hwan;Lee, Hee-Joon;Cha, Guee-Soo
    • The Transactions of The Korean Institute of Electrical Engineers
    • /
    • v.58 no.3
    • /
    • pp.502-508
    • /
    • 2009

  • The method to determine the operating current of HTS magnets needs to be different from that of LTS magnets. This paper presented estimation of the critical current of pancake windings. The pancake windings can be excited by a single power source or by multiple power sources. Critical currents were determined by using field dependent E-J relation. For the better estimation of the critical current, a new method to define the magnetic field of the HTS wire has been proposed. Calculated critical currents of pancake windings were compared with measured ones of the HTS BSCCO magnet consisting of 10 pancake windings. According to the test results, the estimated critical currents of pancake windings agreed well with that of measured ones. Effects of the single and multiple power source excitation on the critical currents have been also examined.

  • PDF KSCI

Design and Fabrication of a Thermoelectric Generator Based on BiTe Legs to power Wearable Device

  • Moon, S.E.;Kim, J.;Lee, S.M.;Lee, J.;Im, J.P.;Kim, J.H.;Im, S.Y.;Jeon, E.B.;Kwon, B.;Kim, H.;Kim, J.S.
    • Journal of the Korean Physical Society
    • /
    • v.73 no.11
    • /
    • pp.1760-1763
    • /
    • 2018

  • To attain power generation with body heat, the thermal resistance matched design of the thermoelectric generator was the principal factor which was not critical in the case of thermoelectric generator for the waste heat generation. The dimension of thermoelectric legs and the number of thermoelectric leg-pairs dependent output power performances of the thermoelectric generator on the human wrist condition was simulated using 1-dimensional approximated heat flow equations with the temperature dependent material coefficients of the constituent materials and the dimension of the substrate. With the optimum thermoelectric generator design, thermoelectric generator modules were fabricated by using newly developed fabrication processes, which is mass production possible. The electrical properties and the output power characteristics of the fabricated thermoelectric modules were characterized by using a home-made test set-up. The output voltage of the designed thermoelectric generator were a few tens of millivolts and its output power was several hundreds of microwatts under the conditions at the human wrist. The measured output voltage and power of the fabricated thermoelectric generator were slightly lower than those of the designed thermoelectric generator due to several reasons.

  • https://doi.org/10.3938/jkps.73.1760 인용 KSCI

A Study on Topology Processor for Substation Automation (변전소 자동화를 위한 위상구조 처리에 관한 연구)

  • Lee, H.J.;Wang, I.S.;Kang, H.J.;Lee, S.G.;Hong, J.H.;Kim, D.J.;Kang, M.C.;Lim, C.H.
    • Proceedings of the KIEE Conference
    • /
    • 2007.07a
    • /
    • pp.21-22
    • /
    • 2007

  • Topology processing is indispensable basic function as it generate a real-time BUS-BRANCH model in Energy Management Systems because most application softwares such as state estimation, power flow, etc., require BUS-BRANCH circuit data. This paper propose an expert system to generate BUS-BRANCH circuit model using Artificial Intelligence technology and it is applied to 154kV distribution substations.

  • PDF

Optimal Inductance of Three-phase High-Power Factor Converter (3상 고역률 AC/DC 컨버터의 부하에 따른 최적 인덕터값)

  • Chun, J.H.;Kim, C.S.;Bark, J.M.;Lee, S.H.;Lee, H.W.
    • Proceedings of the KIEE Conference
    • /
    • 1995.11a
    • /
    • pp.246-249
    • /
    • 1995

  • This paper proposed a partial resonant swtiching three-phase high power factor converter using a lossless snubber. The proposed converter has a merit of simple controlled circuit because tile input current control discontinuously. And it is improve to input power factor that the snubber capacitor's energy regenerate to the AC source side. This topology is reduced a current/voltage stresses of resonant devices in addition to a partial resonant strategy. The result of simulations with the proposed topology included in this paper.

  • PDF