• Title/Summary/Keyword: Minimum power line

Search Result 144, Processing Time 0.039 seconds

Feasible Power Exchange between Russia and ROK Power Systems

  • Kim Jong-Yul;Lee Seung-Ryul;Yoon Jae-Young;Kim Ho-Yong
    • KIEE International Transactions on Power Engineering
    • /
    • v.5A no.3
    • /
    • pp.221-227
    • /
    • 2005
  • This paper evaluates minimum and maximum power exchange considering economic and technical characteristics between Russia and ROK. First, we evaluate minimum power exchange to assure the economic feasibility by comparison with the total cost and benefit of the interconnected line. For evaluating maximum exchange power, system constraints are considered, which are examined through load flow and dynamic analysis by using the PSS/E program. As a result of these evaluations, we suggest the reasonable range of power exchange between ROK and Russia considering economic and technical constraints with the interconnection scenario that power system interconnection between ROK and Russia will be realized in the year 2010.

The Study of Transmission Performance of Line Code on High Speed Optical Transmission Ethernet (고속 광 이더넷에서 선로 부호에 따른 전송 성능에 대한 연구)

  • Kim Chang-Bong;Ko Je Soo;Kim Ik-Sang
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.30 no.6A
    • /
    • pp.510-516
    • /
    • 2005
  • In this paper, we discuss parameters of line code and simulate a same optical ethernet having minimum bandwidth(MB810) and non-minimum bandwidth line code(8B/10B) to present the possibility of improving of transmission performance using minimum bandwidth line code on the high speed optical ethernet. We design the high speed optical ethernet using Serial type LAN PHY 10GBASE-E(WDM type LAN PHY 10GBASE-LX4) for the single(multi) channel link. To compare the transmission performance of MB810, 8B/10B line code we measure the bit error rate(BER) according to the received optical power of single and multi channel link.

On-line Tests of on the Yang-Yang Pumped Storage Plant for the Reactive Power Limits and the OEL Dynamics (양양양수 온라인 무효전력 운전범위 시험과 과여자제한기(OEL) 동특성 시험)

  • Kim, Dong-Joon;Moon, Young-Hwan
    • The Transactions of The Korean Institute of Electrical Engineers
    • /
    • v.56 no.8
    • /
    • pp.1343-1350
    • /
    • 2007
  • This paper describes the tests on the reactive power output limit and the Over-Excitation Limiter (OEL) dynamics of a generation unit. The suggested test methods on reactive limit can identify the allowable maximum/minimum reactive power at 100% rated MW in the steady-state unit operation condition. The on-line OEL test method can identify the time characteristics of OEL with the generation output at 50% of the rated MW. These methods are validated by applying to four Yang-Yang pumped storage units with 282 rated MVA each.

NORDHAUS-GADDUM TYPE RESULTS FOR CONNECTED DOMINATION NUMBER OF GRAPHS

  • E. Murugan;J. Paulraj Joseph
    • Korean Journal of Mathematics
    • /
    • v.31 no.4
    • /
    • pp.505-519
    • /
    • 2023
  • Let G = (V, E) be a graph. A subset S of V is called a dominating set of G if every vertex not in S is adjacent to some vertex in S. The domination number γ(G) of G is the minimum cardinality taken over all dominating sets of G. A dominating set S is called a connected dominating set if the subgraph induced by S is connected. The minimum cardinality taken over all connected dominating sets of G is called the connected domination number of G, and is denoted by γc(G). In this paper, we investigate the Nordhaus-Gaddum type results for the connected domination number and its derived graphs like line graph, subdivision graph, power graph, block graph and total graph, and characterize the extremal graphs.

Line Impedance Estimation Based Adaptive Droop Control Method for Parallel Inverters

  • Le, Phuong Minh;Pham, Xuan Hoa Thi;Nguyen, Huy Minh;Hoang, Duc Duy Vo;Nguyen, Tuyen Dinh;Vo, Dieu Ngoc
    • Journal of Power Electronics
    • /
    • v.18 no.1
    • /
    • pp.234-250
    • /
    • 2018
  • This paper presents a new load sharing control for use between paralleled three-phase inverters in an islanded microgrid based on the online line impedance estimation by the use of a Kalman filter. In this study, the mismatch of power sharing when the line impedance changes due to temperature, frequency, significant differences in line parameters and the requirements of the Plug-and-Play mode for inverters connected to a microgrid has been solved. In addition, this paper also presents a new droop control method working with the line impedance that is different from the traditional droop algorithm when the line impedance is assumed to be pure resistance or pure inductance. In this paper, the line impedance estimation for parallel inverters uses the minimum square method combined with a Kalman filter. In addition, the secondary control loops are designed to restore the voltage amplitude and frequency of a microgrid by using a combined nominal value SOGI-PLL with a generalized integral block and phase lock loop to monitor the exact voltage magnitude and frequency phase at the PCC. A control model has been simulated in Matlab/Simulink with three voltage source inverters connected in parallel for different ratios of power sharing. The simulation results demonstrate the accuracy of the proposed control method.

A feasibility study of interconnection between ROK and Russia (남한-러시아 국가간 계통연계를 위한 예비 타당성 검토)

  • Kim, Jong-Yul;Lee, Seong-Ryul;Yoon, Jae-Young
    • Proceedings of the KIEE Conference
    • /
    • 2005.11b
    • /
    • pp.356-358
    • /
    • 2005
  • This paper evaluates minimum and maximum power exchange considering economic and technical characteristics between Russia and ROK. First, we evaluate minimum power exchange to assure the economic feasibility by comparison with the total cost and benefit of the interconnected line. For evaluating maximum exchange power, system constraints are considered, which are examined through load flow and dynamic analysis by using the PSS/E program. As a result of these evaluations, we suggest the reasonable range of power exchange between ROK and Russia considering economic and technical constraints with the interconnection scenario that power system interconnection between ROK and Russia will be realized in the year 2010.

  • PDF

AuxiliaryPower Device of Spontaneous starting for Railway Vehicle when electric overdischarge or an impossibility of being supplied with control power (밧데리 방전 및 제어 전원 수전불가시 자생기동 가능한 전동차용 보조전원장치)

  • Jeong Soon-You;Kim Sang-Kyun;Lee Hyun-Seok;Lee Kyung-Bok
    • Proceedings of the KSR Conference
    • /
    • 2003.05a
    • /
    • pp.548-553
    • /
    • 2003
  • Battery supplies Each Electric device in Railway vehicles with Control Power. When Battery is overchargedjustly, the battery voltage is not satisfied with the minimum operating voltage, CVCF Inverter(SIV) is supplied with external Power supply or the other railway vehicles and start up CVCF Inverter. In this paper to improve this problem, Dead battery Starter system is proposed. When the battery voltage is not satisfied with the minimum value.turn on the Dead Battery Starter switch, and the Dead Battery Starter supplies the control power to the SIV controller from the line voltage. With this Dead Battery Starter system, the train can be operated when the battery is not proper status. Dead Battery Starter is designed by ROTEM and will be delivered to Attiko Metro Series 2.

  • PDF

Overload Alleviation Algorithm by the Bus Injection Power Control (모선주입전력 조정에 의한 과부하 해소 앨고리즘)

  • 박규홍;정재길;안민옥
    • The Transactions of the Korean Institute of Electrical Engineers
    • /
    • v.39 no.2
    • /
    • pp.111-118
    • /
    • 1990
  • This paper presents a new algorithm of contingency analysis and countermeasure to alleviate the line overloads for electric power systems. In this algorithm, the inverse matrix of the new Jacobian matrix when a contingency occurs, in fastly calculated using the house-holder's Inverse Matrix Modification Lamma (IMML) with the original factor table. The generation outputs are firstly adjusted to alleviate all line overloads occurred by the contingency without tripping loads. If the generation adjustment is not enough anymore to alleviate line overloads, then the control of bus injection power is recommended to quickly alleviate remaining overloads with minimum amount of load tripping and generation read-justing at the termination busbars of the overload lines. The proposed algorithm has been validated in tests on the 6 busbar test system.

  • PDF

A Low-Power ECC Check Bit Generator Implementation in DRAMs

  • Cha, Sang-Uhn;Lee, Yun-Sang;Yoon, Hong-Il
    • JSTS:Journal of Semiconductor Technology and Science
    • /
    • v.6 no.4
    • /
    • pp.252-256
    • /
    • 2006
  • A low-power ECC check bit generator is presented with competent DRAM implementation with minimal speed loss, area overhead and power consumption. The ECC used in the proposed scheme is a variant form of the minimum weight column code. The spatial and temporal correlations of input data are analyzed and the input paths of the check bit generator are ordered for the on-line adaptable power savings up to 24.4% in the benchmarked cases. The chip size overhead is estimated to be under 0.3% for a 80nm 1Gb DRAM implementation.

Design of A Stateless Minimum-Bandwidth Binary Line Code MB46d (Stateless 최소대역폭 2진 선로부호 MB46d의 설계)

  • Lee, Dong-Il;Kim, Dae-Young
    • Journal of the Korean Institute of Telematics and Electronics S
    • /
    • v.35S no.10
    • /
    • pp.11-18
    • /
    • 1998
  • A binary line code, called MB46d, is designed by use of the BUDA(Binary Unit DSV and ASV) cell concept to retain the property of being runlength limited, DC tree, and with a power spectral null at the Nyquist frequency. This new code is a stateless line code with a simple encoding and a decoding rule and enables efficient error monitoring. The power spectrum and the eye pattern of the new line code are simulated for a minimum-bandwidth digital transmission system where the sinc function is used as a basic pulse. The obtained power null at the Nyquist frequency is wide enough to enable easy band-limiting as well as secure insertion of a clock pilot where necessary. The eye is also substantially wide to tolerate a fair amount of timing jitter in the receiver.

  • PDF