• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 B
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• pp.646-651
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• 1996

This paper presents the study results of four transmission methods to enchance transmission capability. The four transmission methods studied were FACTS, HVDC, High Phase Order and new conductor material method. The study was Performed based on mid and long term KEPCO system in 2000 and 2006 year. Among them FACTS(Flexible AC Transmission System) is an exciting new field which holds great promise for improved utilization of AC transmission systems.

• Journal of Power Electronics
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• 제17권1호
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• pp.242-252
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• 2017

This paper deals with the blocking of DC-fault current during DC cable short-circuit conditions in HVDC (High-Voltage DC) transmission systems utilizing Modular Multilevel Converters (MMCs), where a new SubModule (SM) topology circuit for the MMC is proposed. In this SM circuit, an additional Insulated-Gate Bipolar Translator (IGBT) is required to be connected at the output terminal of a conventional SM with a half-bridge structure, hereafter referred to as HBSM, where the anti-parallel diodes of additional IGBTs are used to block current from the grid to the DC-link side. Compared with the existing MMCs based on full-bridge (FB) SMs, the hybrid topologies of HBSM and FBSM, and the clamp-double SMs, the proposed topology offers a lower cost and lower power loss while the fault current blocking capability in the DC short-circuit conditions is still provided. The effectiveness of the proposed topology has been validated by simulation results obtained from a 300-kV 300-MW HVDC transmission system and experimental results from a down-scaled HVDC system in the laboratory.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2005년도 전력전자학술대회 논문집
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• pp.373-375
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• 2005

AC harmonic filters connected to the terminals of HVDC schemes fulfill two primary functions: to compensate for part or all of the reactive power absorbed by the converter, and to limit to an acceptable level the voltage distortion caused by the converter harmonics. this paper makes a direct comparison between tuned filters and damped filters, each designed for a long HVDC transmission scheme. It Is hoped that by comparing the two approaches a syudy to determine the suitability of filter types to AC systems can be promoted.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제55권5호
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• pp.245-249
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• 2006

Corona characteristics of conductors are dependent on the electric field conditions in the immediate vicinity of the conductors. In case of DC transmission line, particularly, the space charge plays an important role in the electric field distribution. Therefore, DC corona cage simulation is necessary for long-term test in the same conditions. This paper presents the results of designing and constructing hardwares such as DC power supply, measurement system and DAS to carry out the simulation. The corona cage longitudinally is divided into five equal length sections and three inner sections of those are isolated from the ground of outer cage. The measurement items are radio noise, corona current, television noise, audible noise and meteorological conditions. In the next step, various simulations about the type and configuration of two or three candidate conductors will be conducted. And then finally an environmentally-friendly conductor for HVDC overhead transmission line will be decided.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 추계학술대회 논문집 전력기술부문
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• pp.162-164
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• 2007

This paper presents a HVDC site selection algorithm to increase transfer capability using VSC HVDC system which can control active power as well as reactive power. Using normal powerflow results and simple index $k_r$ the HVDC site selection algorithm is enhanced and more tightly-coupled transmission lines are identified in a domain of generators.

• 전기학회논문지
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• 제63권6호
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• pp.758-763
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• 2014

These days, the advantages of DC power system are consistently stand out in korea that was a small power loss and high stability. Needs of DC power transmission technology is focused In the midst of a smart grid and environment friendly generation technology boom that is needed for next generation technology. Researches and businesses for HVDC(High Voltage Direct Current) system has been began. But, Needs of HVDC equipment and system commissioning technology are not on the rise until now. In particular, South Korea's HVDC technology is after the foot runner of advanced country and company. In addition, There is no experience for equipment verification and commissioning technology. And Experts of HVDC are rare. Who has been fully understood hardware and system as a whole, and identified all the equipment's characteristic. Recently, Academia and industry are recognized a needs of HVDC technology. But it does not received a recognition of technical value. In this paper, introduce issues when we apply the IEEE's verification method for HVDC system, especially DC current measurement system, DC CT(Direct Current Transformer), among the HVDC equipments. And Proposes remedial methods on the issue in order to recognize the necessity that was HVDC equipments's verification and commissioning technology research should be focused on.

• Journal of Electrical Engineering and Technology
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• 제5권1호
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• pp.54-60
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• 2010

This paper presents a new algorithm for determining generator operation point for maintaining stability considering generator faults in Jeju-Haenam HVDC system. As the HVDC system consumes reactive power for the transmission of active power substantially, compensation of reactive power is essential. And the HVDC system is operated on frequency control mode. That is to say, the HVDC system almost manages system frequency. Therefore, we recognized that the Jeju system could be unstable if the reactive power consumed by the HVDC is insufficient when out-of-step occurs with large generators. When the solution of power flow analysis does not converge due to the unstable system phenomenon, we have difficulty in establishing countermeasures as the post-fault information is not available. In this paper, for the purpose of overcoming this difficulty in establishing countermeasures, we introduce the CPF(Continuation Power Flow) algorithm. This paper suggests an algorithm for calculating the output limitation of the generator to maintain the stability in case of generator fault in the Jeju system.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2012년도 전력전자학술대회 논문집
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• pp.301-302
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• 2012

국내에서 HVDC (High Voltage DC transmission System) 관련 기술은 한국전력공사 및 전력연구원 중심으로 제주와 해남간 설치된 HVDC시스템의 설치 및 운영 기술에 많이 국한되어 왔었다. 그러나 기술을 바탕으로 2010년부터 민간기업인 LS산전과 한국전력공사의 공동 개발을 통하여 60MW ${\pm}80kV$급 전류형 HVDC시스템 설계 및 제작을 추진하여 시스템 설계, 기기 설계 사양, 제작사양서 등의 설계 핵심 기술을 상당부분 확보하는 계기가 되었다. 현재 설계된 Pilot HVDC 시스템은 제작 완료되었고, 제주 실증단지에 설치 및 시험 중에 있으며 2012년 내에 실증운전을 통해서 최종적으로 시스템 설계 기술을 검증할 계획이다. 이 같은 연구를 통하여 상당부분 HVDC 시스템에 대한 독자적인 설계 능력을 갖추게 될 것이다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2013년도 추계학술대회 논문집
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• pp.133-134
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• 2013

현재 LS산전과 한국전력공사의 공동 개발을 통하여 60MW급 ${\pm}80kV$ 전류형 HVDC(High Voltage Direct Current) Transmission System 내 알고리즘 국산화 개발을 진행하고 있다. 제어 알고리즘 여러 레벨(AC Yard Control, Master Control, Pole Control, Phase Control)에서 운전하기 전 여러 고려사항 중 DC Yard 내 DC Switch의 투입/개방의 조건이 있다. 본 논문에서는 이러한 DC Line에 DC Switch의 상태를 효율적으로 제어하는 방법에 대해 소개하고자 한다.

• 대한전기학회논문지
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• 제37권7호
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• pp.434-441
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• 1988

This paper proposes a new invention of the integrated generator converter system for the HVDC transmission. And it analyses the general formula for eddy currents in the rotor iron using the double Fourier series in order to trace the smallest eddy current losses of the system which connects a new designed synchronous generator windings or conventional synchronous generator windings with the v Graetz bridges.