• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.702-703
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• 2011

Large offshore wind farms using high voltage direct current transmission system (HVDC) have been considered and exploited in many countries in the world. The maintenance of the stable operation of wind farm and interconnected system is an important issue, especially in the case of fault. To ensure the stable operation after fault clearance, the PCC voltage must be restored as soon as possible and meet the grid code requirement. This paper will evaluate the PCC voltage recovery ability of a large offshore wind farm as it is connected to a weak grid via a VSC-HVDC.

• Journal of Electrical Engineering and Technology
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• v.4 no.1
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• pp.35-42
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• 2009

When two adjacent AC systems operate at different frequency such as 50Hz and 60Hz, as in the case of ROK and Russia, the only way to practically obtain the advantages of power system interconnection is to use HVDC connection. In this paper, application of the VSC-HVDC transmission for power system interconnection between Russia and ROK is evaluated through the PSCAD/EMTDC modeling and analysis. The simulation results show the feasibility of proposed system for cross border power system interconnection.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.339-340
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• 2015

본 논문에서는 HVDC 제어 시스템의 기능 검증을 위해 구축한 RTDS 기반의 HILS(Hardware-In-the Loop Simulation)시스템 및 시험 결과를 소개하였다. MMC 기반 VSC HVDC는 다수의 직렬 연결된 SM(Sub-Module)을 개별 제어해야 하므로 기존의 LCC HVDC 및 2/3-Level 컨버터 기반의 VSC HVDC와 같은 설비들보다 훨씬 더 복잡한 VBE 구조를 가지고 있다. 또한 짧은 시간 내에 정밀한 제어가 가능해야 하므로 높은 제어 정밀도가 요구된다. (주)효성에서는 제어 시스템의 성능 검증을 위해 RTDS 기반의 HILS(Hardware-In-the Loop Simulation)시스템을 구축하였으며, 이를 이용하여 HVDC 제어 시스템의 성능 시험을 수행하였다. 본 논문에서는 구축된 RTDS 기반의 HILS 시스템 및 시험 결과를 소개하였다.

• Proceedings of the KIPE Conference
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• 2020.08a
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• pp.280-281
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• 2020

본 논문은 MMC 기반의 전압형 HVDC System의 절연설계에 대한 내용을 담고 있다. 절연설계 시 필요한 Surge Arrester 전압결정, 이격거리, 연면거리에 대해 DC측과 AC측을 비교하고 그에 따른 계산 방법에 관한 내용을 기술한다.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.828-829
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• 2011

This paper performs a comparison analysis of two types of HVDC system in Jeju power system. A traditional HVDC transmission system had been composed of line commutated converter based on thyristors and the development of semiconductors enables to apply voltage source converter using IGBTs. The detailed parameters of Jeju power system were considered to make a similar condition with real system in real time digital simulator. Two types of HVDC transmission system were modeled and simulated to compare their characteristics in Jeju power system. The simulation results demonstrate that the VSC-HVDC system has more stable performance due to the fast response speed than LCC-HVDC when the transmission capacity was fluctuated.

• Proceedings of the KIEE Conference
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• 2008.11a
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• pp.491-493
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• 2008

This paper presents results of comparing CSC HVDC with VSC HVDC on the stability in case of connecting Haenam to Jeju electrical power system, the steady-state stability in the case of Jeju electrical power system with CSC HYDC or VSC HVDC, is validated through PV curve, QV curve of Jeju electrical power system. And in the case of CSC HVDC, it is considered that synchronous condenser is connected or not. The results are compared each other. PSS/E simulation tool is used for the steady-state stability analysis.

• The Transactions of the Korean Institute of Power Electronics
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• v.25 no.1
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• pp.61-67
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• 2020

This study deals with the modulation index (MI) of a voltage source converter (VSC) HVDC system based on a modular multilevel converter (MMC). In the two-level converter, the purpose of the MI is to maximize the achievable AC voltage of the converter from a fixed DC voltage. Unlike that in a two-level converter, the MI in the MMC topology plays a role in making the converter a voltage source using a capacitor. The circulating current in the MMC distorts the AC voltage reference, and the distortion affects the MI. In addition, the AC network conditions, such as AC voltage variation and reactive power, affect the MI. Therefore, the MI should be optimized with consideration of internal and external factors. This study proposes a method to optimize the MI of an MMC HVDC system.

• Proceedings of the KIPE Conference
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• 2011.07a
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• pp.85-86
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• 2011

In this paper, the virtual power grid of Jeju in 2020 is modelled including not only VSC HVDC(Voltage Source Current-High Voltage Direct Current) but also wind power generators as 200MW for onshore and 500MW for offshore by PSCAD/EMTDC. Each active power and reactive power are able to controlled by the VSC HVDC. In addition, to verify the characteristic of the modeling VSC HVDC, those wind power generators are cut off from the grid. The result show that the modeling power grid of Jeju become stabilized after 0.1second from failure.

• KEPCO Journal on Electric Power and Energy
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• v.2 no.3
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• pp.343-352
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• 2016

• Proceedings of the KIPE Conference
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• 2017.07a
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• pp.473-474
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• 2017

수도권 부하의 집중과 원거리 발전단지 위치는 우리나라 전력전송의 문제점이며, 전압형 HVDC 적용이 전력전송 문제의 대안이 되고 있다. 초기투자비가 높은 전압형 HVDC 사업의 경제적 타당성 확보의 방법은 기존 시장접근법의 부가가치 편익반영 외에 다른 각도의 다양한 편익산정법의 제안이 필요하다. 본 논문에서는 전압형 HVDC 사업 타당성 확보를 위한 피해비용저감방식의 다양한 편익을 도출하고 경제적 타당성을 제시하였다.