• Proceedings of the KIEE Conference
• /
• 2000.07b
• /
• pp.1396-1398
• /
• 2000

국내에서 운용중인 단권변압기를 사용한 단권변압기(Auto-Transformer) 급전계통이 철도청의 경우 상하선을 전기적으로 구분하여 사용하고 있는 반면, 건설중인 고속철도의 경우 상하선을 병렬연결하고 있어 이에 대한 시뮬레이션을 수행하여 전기적인 장단점을 확인하여 향후 급전계통 방식을 선정하는데 기본 안을 제시한다.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.52 no.2
• /
• pp.55-69
• /
• 2015

Bandwidth enhancement technique for a proximity coupled patch antenna is investigated. The bandwidth and radiation characteristics of a proximity coupled patch antenna with an integrated impedance matching network printed on substrates with various dielectric constants and thicknesses are compared to those of a proximity coupled patch antenna without an impedance matching network. The bandwidth of a proximity coupled patch antenna with an integrated impedance matching network is greatly increased than that of a proximity coupled patch antenna without an impedance matching network without the degradation of radiation characteristics.

• Proceedings of the KAIS Fall Conference
• /
• 2011.05b
• /
• pp.981-984
• /
• 2011

본 논문에서는 산업단지에 공정증기를 공급하는 열병합 발전소 건설에 대한 타당성 분석시 적용되는 기초 경제성 분석에 대한 것으로, 인근의 타 열병합 발전소에서 잉여열을 수열받고 중압급전을 하였을 경우 매전수익 및 기타 소요 금액 산출을 통해 연간 발생되는 발전소 경제성 평가에 목적이 있다. 시스템 구성은 순환유동층보일러, 증기터빈, 복수기, 급수펌프, 탈기기 및 급수가열기 그리고 수처리 설비로 구성되어 있다. 중앙급전 지시를 받을 경우 열원설비인 보일러는 최대부하로 운전되기 때문에 이때 전력생산량이 증가하였으며, 수열을 받을 경우도 수열된 증기는 탈기기 및 급수가열기 등의 열원 및 증기터빈으로 공급되기 때문에 전력생산량이 증가하였다.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.17 no.5 s.122
• /
• pp.427-436
• /
• 2007

The catenary of a high-speed electrical train is modeled by the finite elements with the upper suspension wire, lower contact wire, and droppers, and the dynamic contact between the catenary and the pantograph is numerically analyzed by solving the whole equations of motion of the pantograph and the catenary system subjected to the contact condition. For the stability of the numerical solution, with the cubic spline interpolation of the catenary displacement, the velocity and acceleration constraints as well as the displacement constraint are imposed on the contact point. Through the various numerical examples, it is shown that the dropper positions as well as the static deflection are crucial to determine the contact and separation of the pantograph of a high-speed train.

• Proceedings of the KIPE Conference
• /
• 2010.07a
• /
• pp.355-356
• /
• 2010

일반도로에서 자유주행이 가능한 온라인 전기자동차(On-Line Electric Vehicle, OLEV)에 적용하기 위해 전류원 급전방식의 직렬-직렬 공진형 자기유도 전력전달시스템(Inductive Power Transfer System, IPTS)을 개발하였다. OLEV용 IPTS에서는 급전선로의 누설 인덕턴스가 크고 집전픽업의 유무에 따라 입력측에 유기되는 전압변동이 심한 특성을 반영하여 급전측에 공진형 전류원을 사용한다. 또한 자화 인덕턴스와 집전픽업의 누설 인덕턴스를 포함하여 변압기를 완전 공진시킨다. 본 논문에서는 이러한 방식의 IPTS에서 최대출력을 전달하기 위한 조건을 찾고, 이로써 최대 출력전류 및 출력전력을 제한하는 요인을 찾아 최적설계를 할 수 있도록 하였다. 또한 실험을 통해 그 타당성을 검증하였다.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.16 no.6 s.111
• /
• pp.634-642
• /
• 2006

For the analysis of dynamic contact between a catenary and a pantograph of high-speed electrical train, the numerical solution of the equations of motion of the vehicle pantograph and the catenary system subjected to the contact condition is obtained. The whole equations of motion of the catenary and the pantograph are simultaneously time integrated with the strict application of the contact condition. For the stability of the numerical solution, with the cubic spline interpolation of the catenary displacement, the velocity and acceleration constraints as well as the displacement constraint are imposed on the contact point. Especially it is shown that the Coriolis and centripetal accelerations are critical for the accuracy and stability of the computation.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.19 no.12
• /
• pp.2508-2519
• /
• 1994

In this thesis, two possible schemes for power feeding are considered. The first one is the network power feeding, and the other is the power feeding from the rechargeable battery. Though each scheme has its merits and demerits, the domestic network operator has proposed the latter due to the large deviation of line resistance, high power loss, and safety. This scheme, however, has several problems. The usage is limited by the life of battery leading to the failure of minimal voice service for many hours. The space occupation of that battery is another serious problem. Moreover, the network opeator should have overhead of maintenance and repair. In order to alleviate such the difficulties, the sealing current is introduced through the subscriber loop. Flowing the current into the loop prevents from rusting. This thesis designs a power controller using PEB2025 to control various amount, duration, and period of this sealing current, to achieve the optimum current supply for sealing.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.18 no.6
• /
• pp.220-229
• /
• 2004

The AC railway system is quite differing from the general electric power system because it is single- phase and intermittently heavy loads. Thus, inevitably power quality problems are occurred in the AC railway system, i.e. voltage regulation voltage sags, voltage imbalance, and harmonic distortion. Recently, the power quality of the AC railway system becoming a hot issue because it is affect the control and safety of high-speed traction. In addition it is also affect the power quality of the electric power system. In this paper, single-phase Unified Power Quality Conditioner(UPQS) for the AC railway system is proposed to compensate the voltage sags and harmonic distortion. The configurations and control schemes of the proposed single-phase UPQC are presented. The effectiveness of the proposed single-phase UPQC application is verified by the PSCAD/EMTDC simulation works. It can be shown that the application of UPQC in the AC railway system is very useful to compensate the voltage sags and harmonic distortion from the results of related simulation works.

• 전기의세계
• /
• v.12
• /
• pp.35-42
• /
• 1963

교류철도전화의 급전회로는 전원계통과 전원용변압기의 impedance도 생각하여야하겠으나, 이에 관한 것은 일반 송전문제에 양기되어 있고, 또 전차선로의 급전회로의 impedance가 중요한 입치를 점할뿐만 아니라 전차선로의 급전회로는 1선접지의 단상회로로서 접지측은 rail을 도체로 하여 대지상에 노출된 궤도상의 사이와 침목을 매개로 한 반접지상태의 특수한 회로를 구성하고 있으므로, 일반서지에 기술이 적은 부문에 속한 것같아 여기에 전차선로에 대한 impedance 를 산정하는 실험식과 예를 들어보기로 한다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.17 no.5 s.108
• /
• pp.461-475
• /
• 2006

In this paper, it is described about the tri-band mobile antenna system design to provide broadband multimedia and direct broadcasting services using goo-stationary Koreasat 3, simultaneously operated in Ka/K/Ku band. The radiating part of the antenna system with a fan beam characteristic in the elevation plane is composed of the quasi-offset dual shaped reflector and the tri-band feeder. The tri-band feeder is also composed of the Ka/K dual band feeder with the protruding dielectric rod, the circular polarizer, the ortho-mode transducer and the circular-polarized Ku band feed array. Especially, the Ka/K dual band circular polarizer was realized firstly using the comb-type structure. For fast satellite-tracking on the movement, the Ku band feed array has the structure of the $2{\times}2$ active phased array which can make electrical beams. And, the circular-polarized characteristic in the feed array was improved by $90^{\circ}$ rotating arrangement of four radiating elements polarized circularly by a $90^{\circ}$ hybrid coupler, respectively. Four beam forming channels to make electrical beams at Ku band are divided into the main beam channel and the tracking beam channel in the output, and noise temperature characteristics of each channel were analyzed on the basis of the contributions of internal sub_units. From the fabricated antenna system, the output power at $P_{1dBc}$ of Ka_Tx channel was measured more than 34.1 dBm and the measured noise figures of K/Ku_Rx channels were less than 2.4 dB and 1.5 dB, respectively, over the operating band. The radiation patterns with co- and cross-polarization in the tri-band were measured using a near-field measurement in the anechoic chamber. Especially, Ku radiation patterns were measured after correcting each initial phase of active channels with partial radiation patterns obtained from the independent excitation of each channel. The antenna gains measured in Ka/K/Ku band of the antenna system were more than 39.6 dBi, 37.5 dBi, 29.6 dBi, respectively. And, the antenna system showed good system performances such as Ka_Tx EIRP more than 43.7 dBW and K/Ku_Rx G/T more than 13.2 dB/K and 7.12 dB/K, respectively.