• Title, Summary, Keyword: Electric power loss

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Comparison of iron loss characteristics between thin-gauged grain-oriented 3% Si-Fe sheets and commercial 0.3 mm-thick grain-oriented electrical sheets (극박 방향성 규소강판과 상용 방향성 규소강판의 철손특성 비교)

  • Cho, Seong-Soo;Kim, Sang-Beom;Soh, Joon-Young;Chae, U-Gyu;Han, Sang-Ok
    • Proceedings of the KIEE Conference
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    • pp.2009_2010
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    • 2009
  • Thin-gauged 3% Si-Fe sheets having a high magnetic induction of over 1.9 T have been developed for the purpose of applications where operation frequency is higher than power frequency. In order to clarify requirements of iron loss characteristics for the applications, iron loss characteristics of the newly developed strip were investigated by iron loss separation method and were compared with those of commercially produced 0.3 mm-thick electrical sheets. In case of relatively high excitation induction(1.7 T) and low frequency(60 Hz), reducing hysteresis loss is effective to decrease total iron loss. In case of relatively low excitation induction(1.0 T) and high frequency(1 kHz), reducing eddy-current loss is effective by decreasing thickness and grain size to improve total iron loss.

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Investigation on Effective Operational Temperature of HTS Cable System considering Critical Current and AC loss

  • Kim, Tae-Min;Yim, Seong-Woo;Sohn, Song-Ho;Lim, Ji-Hyun;Han, Sang-Chul;Ryu, Kyung-Woo;Yang, Hyung-Suk
    • KEPCO Journal on Electric Power and Energy
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    • v.2 no.2
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    • pp.307-310
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    • 2016
  • The operational cost for maintaining the superconductivity of high-temperature superconducting (HTS) cables needs to be reduced for feasible operation. It depends on factors such as AC loss and heat transfer from the outside. Effective operation requires design optimization and suitable operational conditions. Generally, it is known that critical currents increase and AC losses decrease as the operational temperature of liquid nitrogen ($LN_2$) is lowered. However, the cryo-cooler consumes more power to lower the temperature. To determine the effective operational temperature of the HTS cable while considering the critical current and AC loss, critical currents of the HTS cable conductor were measured under various temperature conditions using sub-cooled $LN_2$ by Stirling cryo-cooler. Next, AC losses were measured under the same conditions and their variations were analyzed. We used the results to select suitable operating conditions while considering the cryo-cooler's power consumption. We then recommended the effective operating temperature for the HTS cable system installed in an actual power grid in KEPCO's 154/22.9 kV transformer substation.

AC loss Measurement of Superconducting Power Cable (초전도 전력케이블의 교류손실 측정)

  • Hwang, Si-Dole;Hyun, Ok-Bae;Sohn, Song-Ho;Choi, Hyung-Sik
    • Proceedings of the KIEE Conference
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    • pp.524-526
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    • 2005
  • As a research activity of the project of "Verification Test of Superconducting Power Cable", we measured the AC loss of a short length superconducting power cable. The rating and the length of the cable were 22.9kV, 1,250A and 2.2m. The voltage taps for measuring the AC loss were attached to both ends of the conductor of the superconducting cable. Through the voltage taps and a lock-in amplifier we measured the in-phase component of the voltage($V_x$) with the load current(I). The AC loss was measured by multiplying the in-phase component of the voltage($V_x$) by the load current(I). The value of the AC loss of the superconducting power cable was 1.18W/m/phase/kA at 77.3K, 1atm.

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Design of the Bare Electric Wire for Low Loss (나전선(裸電線)의 저손실화 설계)

  • Jeong, Y.H.;Lee, H.K.;Shon, H.K.;Cho, Y.K.
    • Proceedings of the KIEE Conference
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    • pp.101-103
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    • 1998
  • New transmission lines are gradually constructed with high voltage and power for increase of electric power demands. And electric losses that are produced in line are increased. we made the algorithm for low loss wire and developed the computer program that makes loss of electric wire to be decreased for efficient power transmission. Electric wire is designed not to be decreased electrical and mechanical properties than that of existing electric wire.

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Loss Minimizing Vector Control of Interior Permanent Magnet Synchronous Motor (매입형 영구자석 동기전동기의 최소 손실 벡터제어)

  • Chung, Euihoon;Lee, Yongjae;Ha, Jung-Ik
    • The Transactions of the Korean Institute of Power Electronics
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    • v.20 no.4
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    • pp.330-336
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    • 2015
  • This paper presents a loss-minimizing vector control method for interior permanent magnet synchronous motor (IPMSM). Conventionally, maximum torque per ampere (MTPA) control, which minimizes copper loss, has been widely used in industry. Iron loss, however, is not considered in MTPA control. In this paper, the loss model, including iron loss and copper loss, is derived to further reduce drive loss. The loss-minimizing vector controller is implemented based on the loss model. The controller generates optimal current vectors according to the operating conditions. The performance and validity of the proposed method are proved by experimental results through comparison with conventional methods.

Reduction of Power Disturbance by Contact Loss Phenomenon of a High Speed Electric Train Using Passive Filters (수동필터를 이용한 고속전철 이선현상에 의한 전원외란 저감)

  • Chang, Chin-Young;Jin, Kang-Hwan;Kang, Jeong-Nam;Park, Dong-Kyu;Kim, Yoon-Ho
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.59 no.2
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    • pp.206-211
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    • 2010
  • Since high-speed train is a dynamic load in which electric power is externally supplied, contact loss between the catenary and pantograph occurs. This phenomena including vibrations generates frequently irregular arcs, which, in turn causes EMI. Thus it is very important to develop the approach to reduce arc phenomenon by contact loss, as speed of electric railway vehicle increases. In case of an electric railway vehicle using electrical power, compared with diesel rolling stock, Power Line Disturbance(PLD) such as harmonics, transient voltage and current, Electromagnetic Interference(EMI), and dummy signal injection etc usually occur. In this study, the dynamic characteristics of a contact wire and a pantograph suppling electrical power to high-speed train are investigated with an electrical response point. To implement power line disturbance induced by contact loss phenomenon for high speed train operation, a hardware simulator which considers contact loss between contact wire and pantograph as well as contact wire deviation is developed. It is confirmed by the experiments that contact loss effect is largely dependent on voltage conditions when the contact loss occurs. Also, a passive filter is designed to reduce power disturbance and the designed system is verified by experiment.

A Development of Simulator to Assessment for Loss Saving of Harmonic Electric Power Energy (고조파 전력에너지의 손실절감량 산정 시뮬레이터 개발)

  • Kim, Yong-Ha;Jo, Hyun-Mi;Heo, Dong-Ryeol;Park, Jong-Min;Park, Hwa-Yong;Yoo, Jeong-Hui
    • Proceedings of the KIEE Conference
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    • pp.1272-1273
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    • 2011
  • A study on demonstration to development of simulator to assessment for loss saving of harmonic electric power energy. harmonic occurs to electric equipment like increase of terminal voltage, resonance phenomena occurrence and noise. To circulate of loss saving of harmonic electric power energy, we assessment electric power loss saving by harmonic and estimate loss saving of far-infrared radiation panel heating system.

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Electric Power Loss Comparison Study for Regenerative Utilization Technologies in DC Electric Railway Systems (철도차량 회생에너지 활용기술별 가선 손실 저감 효과 비교 분석 연구)

  • Lee, Hansang;Kim, Jinhak;Kim, Hyun
    • Proceedings of the KIEE Conference
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    • pp.1597-1598
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    • 2015
  • Regenerative power utilization is one of the most interesting issue in electric railway systems. Generally, technologies to utilize regenerative power from railway vehicles are railway substation with regenerative inverter, on-station energy storage systems, and on-board energy storage systems. In this paper, the electric power loss for those technologies is calculated and compared using DC electric railway system analysis algorithm.

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LOSS OF OFFSITE POWER TEST EXPERIENCE FOR YGN 4

  • Chi, Sung-Goo;Sung, Kang-Sik;Kim, Se-Chang;Kim, Eul-Ki;Eom, Young-Meen;Park, Young-Boo
    • Proceedings of the Korean Nuclear Society Conference
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    • pp.230-234
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    • 1995
  • The loss of offsite power test was successfully performed on YGN 4 to demonstrate that the reactor can be shutdown and the RCS can be maintained in a hot standby condition following a loss of all offsite Alternating Current (AC) power. Following the loss of main generator and all offsite AC power, the ensile emergency diesel generators were automatically started and the plant was stabilized via natural circulation. Plant conditions were maintained in hot standby for at least 30 minutes before offsite power was restored. Thus, the capability of equipment, controls and instrumentation necessary to remove decay heat from the core using only ensile emergency power was demonstrated, thereby satisfying all objectives and acceptance criteria of the test.

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