• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.9
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• pp.1638-1643
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• 2010

HVDC is better economic method than HVAC in case of long distance transmission and it is possible to interconnect transmission lines regardless of difference of power frequency. The electrical environment problems of HVDC overhead transmission line are electric field, charged voltage, ion current and so on. For biopolar HVDC lines, most of the ions are directed toward the opposite polarity conductor, but a significant fraction is also directed toward the ground. These problems are major factor to design configuration of HVDC overhead transmission line. Therefore, It is necessary to test an environmental characteristics of HVDC overhead transmission line. In this paper, to assess the ion characteristic of HVDC transmission line, continuous measurements have been done on the biopolar single circuit line with ACSR 480mm2-6 bundle conductors of Gochang HVDC Test line. And then the ion characteristics were analyzed.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.10
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• pp.1454-1459
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• 2017

In spite of continuous increase of electric power demand and new generation plants, it is very difficult to install new transmission line. Therefore, it comes to be difficult to operate the power system stable, so it is required to find another way to get new transmission capacity. Because HVDC transmission system installation is the one of the best option for us, we have undertake the HVDC project in mainland. Buckdangjin-Goduck HVDC project(500kV, 3GW) is currently under construction and Eastern Power HVDC project(500kV, 8GW) is under the study for technical specification. Both of them have the Run-up SPS function for taking action of 765kV Transmission line fault. The Run-up SPS function increases the active power output of the HVDC rapidly when the transmission line between the power plant and network is tripped, thereby preventing the generator from overspeed and improving the power system stability. In this paper, we propose MEAC(Modified Equal Area Criteria) method based on traditional EAC method to quantitatively evaluate the effect of the HVDC run-up SPS function on the power system stability improvement.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.12
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• pp.1675-1681
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• 2017

As recently the demand on electric power has been increasing, the requirement of power supply reliability has been increased. Accordingly, the number of HVDC transmission systems in the world has been steadily increased, which have been installed in the power system to transmit a large capacity power to the long distant and interconnect the power grid between different countries. etc. #1 HVDC Transmission System was installed between Haenam and Jeju island in 1998, which is the first HVDC system furnished in korea. and has been operated until now. Before #1 HVDC Transmission System being installed, the power system of the Jeju Island is a isolated power system from that of Korea mainland. After the construction of #1 HVDC the system has made the Jeju power system more reliable and also been able to supply the mainland power, which was cheaper than that of Jeju island, to Jeju island. The construction of additional HVDC transmission system between mainland and the Jeju Island has been currently underway to cope with recent changes of the power market of the Jeju island, for examples the increase of power demand and the capacity of wind power generation. etc. #2 HVDC Transmission System construction was completed in 2012. #3 HVDC Transmission System will be also installed according to the plan. If all goes as planned, the Jeju power system will be operated with Multi-Infeed HVDC system connected to mainland power system. So the additional studies are needed in order to maintain the stability of the Jeju power system and get the efficiency of the Multi-Infeed HVDC system. Therefore, in this paper, the optimal operation strategies of the Multi-Infeed HVDC system between the mainland of Korea and the Jeju are suggested to ensure the stability of the power system in Jeju Island when the Multi-Infeed HVDC system is operated between two power system.

• Journal of Electrical Engineering and Technology
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• v.13 no.1
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• pp.105-113
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• 2018

This paper proposes pre-analysis on planning of high-voltage direct current (HVDC) transmission system applied to Korea electric power grid. HVDC transmission system for interface lines has been considered as alternative solution for high-voltage AC transmission line in South Korea since constructing new high-voltage AC transmission lines is challenging due to political, environmental and social acceptance problems. However, the installation of HVDC transmission system as interface line in AC grid must be examined carefully. Thus, this paper suggests three scenarios to examine the influences of the installation of HVDC transmission system in AC grid. The power flow and contingency analyses are carried out for the proposed scenarios. Power reserves in metro area are also evaluated. And then the transient stability analysis focusing on special protection scheme (SPS) operations is analyzed when critical lines, which are HVDC lines or high voltage AC lines, are tripped. The latest generic model of HVDC system is considered for evaluating the impacts of the SPS operations for introducing HVDC system in the AC grid. The analyses of proposed scenarios are evaluated by electromechanical simulation.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.48 no.3
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• pp.247-256
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• 1999

In this paper, a methodology for optimal design of PID controller using the modified genetic algorithm has been proposed to improve the transient stability at system fault in HVDC transmission system, mathematical model preparation for stability analysis, and supplementary signal control by an optimal PID controller using the modified genetic algorithm(MGA). The propriety was verified through computer simulations regarding transient stability. It means that the application of MGA-PID controller in HVDC transmission system can contribute the propriety to the improvement of the transient stability in HVDC transmission system and the design of MGA-PID controller has been proved indispensible when applied to HVDC transmission system.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.1102-1103
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• 2015

The researchers worldwide have been trying to apply high temperature superconducting wire for power system devices. High voltage direct current (HVDC) transmission system has been used for bulk and long-distance power transmission. The authors designed a laboratory-scale superconducting DC transmission line to investigate its applicability to an HVDC system. The superconducting DC transmission line was simulated in connection to a laboratory-scale HVDC system using PSCAD/EMTDC. The operating characteristics of the superconducting DC transmission line connected to HVDC system and the effects of the superconducting DC transmission line on HVDC system were analyzed and compared with the results of a conventional DC transmission line. The results of operating characteristics for the superconducting DC transmission line were discussed in detail.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.4
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• pp.554-560
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• 2018

Since Korea has a small land area, it is expected to construct the conductor return type with neutral wire in the case of ${\pm}500kV$ HVDC double bipole transmission line. Therefore, in order to apply ${\pm}500kV$ HVDC double bipole transmission line with neutral wire in Korea, it is necessary to develop technology for insulation and environmental designs. In this study, radio interference, audible noise, electric field and ion current density according to the polarity arrangement were compared and assessed in the ${\pm}500kV$ HVDC double bipole transmission line with the conductor return method. And the optimum configuration of HVDC double bipole transmission line was determined from the viewpoint of electrical environment.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.51 no.7
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• pp.317-326
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• 2002

In this paper, a methodology for optimal PI supplementary controller using the modified genetic algorithm has been proposed to the oscillation damping in HDVC transmission system. These study processes are summarized as the formulation for load flow calculation in HVDC transmission system with SVC, the investigations on the basic control in HVDC system, the mathematical modeling for dynamic characteristics analyses, and the optimal design of MGA based PI controller generation the supplementary control signal of SVC. Its properties were verified through a series of computer simulations including dynamic stability. It means that the application of MGA-PI controller in HVDC transmission system can contribute the propriety to the improvement of the stability in HVDC transmission system and the design of MGA-OI controller has been proved indispensible when applied to HVDC transmission system.

• The Transactions of the Korean Institute of Power Electronics
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• v.21 no.5
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• pp.442-448
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• 2016

This paper presents electromagnetic force effect of the conductor and insulator in the HVDC valve hall. This paper is based on IEC 60865, which is applicable to the mechanical and thermal effects of short-circuit currents. The paper contains procedures for the calculation of the electromagnetic effect on HVDC conductors and flexible conductors, as well as the thermal effect on HVDC conductors. The results are applied to the Godeok -Dangjin HVDC system.

• Journal of Electrical Engineering and Technology
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• v.9 no.3
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• pp.1002-1008
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• 2014

This paper describes insulation design and its reliability evaluation of ${\pm}80kV$ HVDC XLPE cable. Recently, the construction of HVDC transmission system, which is combined overhead line with underground cable, has been completed. This system is installed with existing 154 kV AC transmission line on the same tower. In this paper, the lightning transient analysis is firstly reviewed for selection of basic impulse insulation level and nominal insulation thickness. Then the electrical performance tests including load cycle test and superimposed impulse test based on CIGRE TB 496 are performed to evaluate the reliability of newly designed HVDC cable. There is no breakdown for ${\pm}80kV$ HVDC XLPE cable during electrical performance test. Finally, this system is installed in Jeju island based on successful electrical performance test (Type test). After installation tests are also successfully completed.