• Proceedings of the KIEE Conference
• /
• 2006.04b
• /
• pp.238-240
• /
• 2006

논문은 전류원 HVDC로 연계되어 있는 제주-해남 계통을 전압원 HVDC로 연계하였을 경우에 대한 특성 분석에 대해서 기술하고 있다. 기존의 제주-해남 HVDC시스템은 교류계통 전압의 외란에 의해서 전류실패가 발생할 수 있으므로 연계되는 교류계통 모선에 무효전력보상설비들이 설치되어 있다. 따라서 기존의 전류원 HVDC 시스템은 대용량의 전력을 전송할 수 있다는 장점이 있는 반면 추가로 무효전력 보상설비들이 설치가 되어야 한다는 단점이 있기 때문에 최근에 선진국에서는 전압원 HVDC 시스템에 대한 연구가 활발히 진행되고 있다. 전압원 HVDC 시스템은 계통사고 또는 교류전압강하로 인한 전류실패가 발생하지 않고, 무효전력을 HVDC 시스템의 용량내에서 유효전력과 독립적으로 제어될 수 있기 때문에 추가로 무효전력 보강설비가 필요하지 않다는 장점이 있다. 본 논문에서 늘 제주-해남 계통을 전압원 HVDC로 연계하는 모델을 PSCAD/EMTDC를 이용해서 개발하였다. 개발된 시뮬레이션 모델은 전압원 HVDC를 이용해서 제주-해남 계통을 연계하였을 경우에 대한 동특성을 분석하는데 유용하리라 사료된다.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.19 no.6
• /
• pp.494-502
• /
• 2014

This paper presents a control method of the modular multilevel converter - high-voltage direct current (MMC-HVDC) system to regulate grid voltage on the basis of the Jeju Island power system. In this case, the MMC-HVDC system is controlled as a static synchronous compensator (Statcom) to exchange the reactive power with the power grid. The operation of the MMC-HVDC system is verified by using the PSCAD/EMTDC simulation program. The Jeju Island power system is first established on the basis of the parameters and measured data from the real Jeju Island power system. This power system consists of two line-commutated converter - high-voltage direct current (LCC-HVDC) systems, two Statcom systems, wind farms, thermal power plants, transformers, and transmission and distribution lines. The proposed control method is then applied by replacing one LCC-HVDC system with a MMC-HVDC system. Simulation results with and without using the MMC-HVDC system are compared to evaluate the effectiveness of the control method.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.19 no.2
• /
• pp.145-151
• /
• 2005

Cheju-Haenam HVDC link transmits electrical power up to 300[MW] Because of its size, HVDC system has a great potential for damping power system oscillations. This paper with the frequency control of the KEPCO HVDC system linking Haenam to Cheju island. Frequency control at Cheju island ensures that the island AC system frequency is maintained Performance are evaluated using a reduced Cheju network and a detailed model of the fm system modelled in the PST software. Transient oscillations for the 3 phase fault carried out with HVDC frequency control are well damped as the control parameters have been adjusted.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.25 no.6
• /
• pp.459-468
• /
• 2020

The pole interaction of the line-commutated converter high-voltage direct current (HVDC) is analyzed, and a practical solution that uses a surge arrester is proposed. Jeju HVDC No. 2 is a double-monopole HVDC link that has a rated power capacity of 2 × 200 MW and was commissioned in 2012. During normal operation, Jeju HVDC No. 2 is operated in the bipolar mode to minimize the loss caused by the dedicated metallic return. However, when one pole of the inverter valve is bypassed, a commutation failure can occur in the other pole. This phenomenon is called pole interaction in this work. This pole interaction interrupts the HVDC power transfer for almost 2 s and may affect the stability of the power system. This research proposes the installation of a surge arrester at the inverter neutral, which can be an effective and practical solution for pole interaction. The HVDC system is analyzed, and the residual voltage of the surge arrester is determined. Detailed simulation using PSCAD/EMTDC demonstrates that the proposed method eliminates the pole interaction of the bipolar-operated HVDC.

• Proceedings of the KIPE Conference
• /
• 2017.07a
• /
• pp.389-390
• /
• 2017

본 논문은 전압형 HVDC 시스템의 기술 동향에 대하여 설명하고 있다. 전압형 HVDC 시스템은 무효전력소모가 있고, 전류형 HVDC 시스템은 무효전력 소모가 없기 때문에 시스템의 구성과 제어에 많은 차이를 보이고 있다. 본 논문은 이러한 현황을 요약 정리한 논문이다.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.13 no.5
• /
• pp.344-351
• /
• 2008

The benefits of utilizing energy exchange between the main land and Cheju island in Korea make it interesting to establish new HVDC sea cable interconnections. A total power of 350 MW or more can then be exchanged through the HVDC links including the existing Cheju HVDC #1 interconnection. A feasibility study base on economical benefits has been carried out. Especially the comparison of economy benefit between thermal power plant, LNG power plant and HVDC system shows that HVDC system is the only solution in Cheju island. Also, this paper shows that additiona 1 HVDC system help to enhance the stability of power system.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.62 no.1
• /
• pp.8-20
• /
• 2013

This paper deals with the concept design of HVDC system for controlling AC network reactive power. HVDC system can control active power and reactive power and the control concept of reactive power is similar to SVC(Static Var Compensator). Reactive power is controlled by adjusting firing angle of HVDC system under the condition that AC filters are switched. Reactive power depends on AC voltage condition, considering the steady-state and transient state to maintain the stable operation of AC network in the viewpoint of voltage stability. Therefore, in the design stage of HVDC, the reactive power required in the AC network must be considered. For the calculation of operation angle in HVDC system, the expected reactive power demand and supply status is examined at each AC system bus. The required reactive power affects the determination of the operation angle of HVDC. That is, the range of "control deadband" of operation angle should have the capability supplying the required reactive power. Finally, the reactive power control concepts is applied to 1GW BTB Pyeongtaek-Dangjin HVDC system.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.61 no.6
• /
• pp.833-837
• /
• 2012

In HVDC System, the rapid voltage breakdown between anodes and cathodes during valve firing causes radio interference in HVDC converter station. These voltage breakdown causes steep current pulse and inject current in system. As a result, harmonic frequencies are generated from valve, switchyard. In this paper, theoretical background of radio interference in HVDC converter is discussed and its reduction method for radio interference is proposed.

• Journal of Power Electronics
• /
• v.7 no.3
• /
• pp.233-237
• /
• 2007

This paper deals with the new HVDC interaction which was observed in the Jeju-Haenam HVDC system. The interaction is not from a system malfunction or controller loop problem but from the change of AC network scheme and the network operating condition. We have found that the interaction is caused by the voltage oscillation between synchronous compensator and HVDC shunt reactor. We analyzed the cause of the interaction and suggested a solution.

• Proceedings of the KIEE Conference
• /
• 2011.07a
• /
• pp.268-269
• /
• 2011

제주도는 내륙과 EJfdjwu 있는 섬으로 독특한 계통 특성을 가지고 있다. HVDC는 제주 계통을 내륙 계통과 연계시켜 안정적인 전력 공급과 주파수 유지를 담당하고 있다. 현 제주-해남 사이의 이외에 추가로 제주-진도 사이의 2단계 HVDC가 2011년 12월 완공을 목표로 건설되고 있다. 1단계 HVDC와 풍부한 바람 자원을 이용한 풍력 발전 단지가 운영 중이고, 해안 풍력 발전 단지 뿐만 아니라 해상 풍력 발전단지도 건설될 예정이다. 또한 스마트그리드 실증단지가 제주도에 건설될 예정이기 때문에 향후 풍력 발전량이 더욱 증가할 전망이다. 2013년 이후부터는 추가 건설될 2단계 HVDC와 현재 운영되고 있는 1단계 HVDC가 협조 운전을 하게 된다. 풍력 발전 단지의 증가와 추가 HVDC는 제주 계통의 전원 구성에 변화가 예상된다.