• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.153-154
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• 2015

Voltage Source Converter HVDC (VSC-HVDC) are a better alternative than conventional thyristor based HVDC systems. Unfortunately, VSC-HVDC's full potential cannot be utilized up till now due to absence of suitable HVDC protection. Recently, hybrid HVDC circuit breakers (HDCCB) have been developed and successfully lab tested. However, their application and feasibility in VSC-HVDC needs to be investigated. In this research paper we have modelled an existing HDCCB and evaluated its impact on fault reduction and interruption in VSC-HVDC systems. The HDCCB was applied in Korean Jeju-Haenam VSC-HVDC system model and its impact was analyzed for HVDC line-to-ground and line-to-line faults. HDCCB successfully interrupted the fault current and prevented the damages to costly IGBTs and converter transformers.

• Journal of the Korean Society of Industry Convergence
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• v.24 no.4_1
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• pp.377-385
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• 2021

High voltage direct current(HVDC) systems has been an alternative method of a power transmission to replace high voltage alternate current(HVAC), which is a traditional AC transmission method. Due to technical limitations, Line commutate converter HVDC(LCC-HVDC) was mainly used. However, result from many structural problems of LCC-HVDC, the voltage source converter HVDC(VSC-HVDC) are studied and applied recently. In this paper, after analyzing the reactive power and output voltage ripple, which are the main problems of LCC-HVDC, the characteristics of each HVDC are summarized. Based on this result, a new LCC-HVDC structure is proposed by combining LCC-HVDC with the MMC structure, which is a representative VSC-HVDC topology. The proposed structure generates lower reactive power than the conventional method, and greatly reduces the 12th harmonic, a major component of output voltage ripple. In addition, it can be easily applied to the already installed LCC-HVDC. When the proposed method is applied, the control of the reactive power compensator becomes unnecessary, and there is an advantage that the cut-off frequency of the output DC filter can be designed smaller. The validity of the proposed LCC-HVDC is verified through simulation and experiments.

• The Transactions of the Korean Institute of Power Electronics
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• v.6 no.1
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• pp.1-12
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• 2001

This paper deals with HVDC simulation. And the purpose of this paper is to reproduce measurements recorded at HVDC site and to verify the control gains and control actions. In this paper, the target of simulation study is Cheju-Haenam HVDC system. Because Cheju-Haenam HVDC system include analogue controller and digital controller, the detailed digital model considered nonlinear characteristics of analogue controllers is development for high accurate firing and control action. Finally the simulation results which is simulated by PSCAD/EMTDC is compared with measurement signals.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.12
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• pp.2196-2201
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• 2011

According to the 5th national plan for electric power demand and supply, the 3rd HVDC link will be installed between KEPCO and Jeju Island system and go into operation in June, 2016. However, if it adopt LCC HVDC, Jeju power system could be in voltage instable condition. In order to solve the problem, we propose the application of VSC HVDC to the 3rd HVDC project. In the past, VSC HVDC has many disadvantages such as, inefficiency in conversion, size limit, and expensiveness, compared to LCC HVDC. Recently, the new technologies and the demand for renewable energy interconnection are leading a large growth in VSC HVDC market. In this paper, we will introduce the technical and market trends of VSC HVDC and power system stability analysis results for Jeju power system having LCC and VSC HVDCs.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.9
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• pp.1514-1522
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• 2010

This paper dealt with the HVDC concept design of Cheju HVDC #2, which will be operated at 2011. The concept design is the first step of HVDC design procedures and the contents which were presented in this paper, are HVDC operation conditions based on the reliability of HVDC and AC network conditions, short circuit ratios(SCR) to related to HVDC stability and overvoltage and interactions between AC network including FACTS and generators, and HVDC system. The results of this paper are a keystone of HVDC #2 design.

• The Transactions of the Korean Institute of Power Electronics
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• v.10 no.1
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• pp.1-12
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• 2005

This paper deals with the HVDC stability according to controller types and control modes. From the viewpoint of controllers, the HVDC system which has PI, PD and PID, is designed considering the system response and stability. Also the HVDC system consists of multi-control modes like voltage control, current control and alpha control. Therefore, the HVDC stability analysis have to consider the above control modes and controller types. In this paper, the reduced model of HVDC control is analyzed in PSS/E(Power System Simulation/Engineering) and PSCAD/EMTDC.

• Proceedings of the KIPE Conference
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• 2010.07a
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• pp.581-584
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• 2010

The background of this paper is the HVDC concept design of Jeju HVDC #2, which will be operated at 2011. The concept design is the first step of HVDC design procedures and the contents handled in this procedure are operation conditions, short circuit ratios(SCR) and interactions between AC network and HVDC. The operating conditions are based on the reliability of HVDC and AC network, SCR is related to HVDC stability and overvoltage and the interaction is between HVDC and other AC equipments, that are FACTS, generator and HVDC. The results of this paper are a keystone of HVDC #2 design.

• Journal of Electrical Engineering and Technology
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• v.12 no.2
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• pp.594-600
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• 2017

HVDC transmission systems can be configured in many ways to take into account cost, flexibility and operational requirements. [1] For long-distance transmission, HVDC systems may be less expensive and suffer lower electrical losses. For underwater power cables, HVDC avoids the heavy currents required to charge and discharge the cable capacitance of each cycle. For shorter distances, the higher cost of DC conversion equipment compared to an AC system may still be warranted, due to other benefits of direct current links. HVDC allows power transmission between unsynchronized AC transmission systems. Since the power flow through an HVDC link can be controlled independently of the phase angle between the source and the load, it can stabilize a network against disturbances due to rapid changes in power. HVDC also allows the transfer of power between grid systems running at different frequencies, such as 50 Hz and 60 Hz. This improves the stability and economy of each grid, by allowing the exchange of power between incompatible networks. This paper proposed to establish Korean HVDC technology through a cooperative agreement between KEPCO and LSIS in 2010. During the first stage (2012), a design of the ${\pm}80kV$ 60MW HVDC bipole system was created by both KEPCO and LSIS. The HVDC system was constructed and an operation test was completed in December 2012. During the second stage, the pole#2 system was fully replaced with components that LSIS had recently developed. LSIS also successfully completed the operation test. (2014.3)

• KIPE Magazine
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• v.6 no.4
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• pp.21-26
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• 2001

HVDC Light는 300MW에 이르는 전력을 가지고 있는 아불 성형된 DC Cable과 Voltage Source 컨버터에 기반을 둔 가장 최근의 HVDC 기술이다. HVDC Light 컨버터는 IGBT(Insulated Gate bi-polar Transistor)와 유효전력과 무효전력 사이의 고속 컨트롤을 위한 PWM(펄스 폭 변조)의 기능을 가지고 있다. HVDC Light 케이블은 압출 성형된 폴리머의 절연을 가진 케이블이며 직류 전압을 위해 특별히 개조되었다. 전력 범위 내에서 HVDC Light 컨버터와 케이블은 지중 또는 해저 송전 등에서도 송전전력을 위해 훌륭하게 조합될 수 있었다. 본 원고는 실제의 케이스로부터 얻은 경험지식으로, HVDC Light 기술의 조합을 사용해 해결된 문제점을 소개하고, HVDC Light의 장점을 설명하였다.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.388-389
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• 2011

최근 보급이 확대되고 있는 HVDC는 설치 당시의 상황 등에 따라 제어기가 달라지게 되므로, HVDC 프로젝트마다 제어기가 달라지게 된다. 따라서 PSS/E 프로그램에는 HVDC 설비를 위한 전용의 HVDC 모델을 개발할 수 있는 Model Writing 기법을 제공하고 있다. 하지만 국내에서는 UDM 개발 기술이 널리 전파되지 않아 UDM 기술기반이 취약한 상태이다. 이에 본 논문에 CIGRE HVDC 벤치 마크 모델에 대한 UDM을 개발하여 전용의 HVDC 모델을 개발하기 위한 기반기술을 확보하였다.