• 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
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• v.63 no.5
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• pp.636-643
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• 2014

Length of most underground power cable in nation is not so long. Therefore it is operated without conductor transposition due to low unbalanced ratio. However, if cable length is long, line constant of each cable will be different. Different line constant can induce unbalanced voltage and current of sheath. Also it can induce several induced interference. This paper describes the operation effectiveness through steady and transient analysis on transposition and untransposition of cable conductor. Especially sheath current and induced voltage are analyzed and compared in case of transposition and untransposition. EMTP is used for modeling and analysis.

• Proceedings of the KIEE Conference
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• 2006.07a
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• pp.450-451
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• 2006

The method of conductor wiring is that a messenger wire is installed, the end of the wire is connected to the conductor and a engine puller pulls the conductor. The length of one section of wiring is $3{\sim}5km$ and one group messenger wire pulls simultaneously $2{\sim}4$ group conductor, while a tensioner maintains wiring tension to prevent the deflection of the conductor. However, there are many obstacles such as roads, power lines, communication lines, buildings, farms and crops. Therefore to prevent damage from conductor deflection a staging is used. The currently used staging is scaffolding lumber which is difficult to secure and it's construction efficiency is very low because it requires a lot of time and manpower. So this study developed a insulating defense tube and pipe connecting device, and a truss structure fabrication module using steel pipe which reduces construction time and cost through a compressive and dielectric strength test.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.10
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• pp.1881-1887
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• 2009

This paper discusses the effects of ECC (Earth Continuity Conductor) for reducing the level of induced sheath overvoltages at the single point bonded section of combined transmission lines which are mixed underground power cable with overhead line in one T/L. In previous papers, the characteristics of ECC on only underground power cable systems were sufficiently analyzed. However, the result of only underground power cable systems are totally different from that of combined transmission lines because ECC is commonly grounded with overhead grounding wire at mesh of cable head. Therefore, in this paper, the installation effects of ECC have been variously analyzed considering the three kinds of fault positions, cable formation of duct and trefoil, spacing between phase conductor and ECC, and the change of overhead transmission line section length on 154kV combined transmission line. Finally, simulation results show that ECC can effectively reduce the induced sheath voltage.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.50 no.12
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• pp.556-560
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• 2001

To solve aeolian noise, we have tried several special conductor bundles equipped with spiral rod and one kind of low aeolian noise conductor with a special shape. Charge simulation method was applied to analyze electric field distributions of them in transmission line and corona cage for investigating the corona characteristics. This paper describes the electric field distributions and the performances of audible noise and radio interference from the special bundles in 765 kV transmission line by using corona characteristics obtained from corona cage simulation.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.215-215
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• 2009

Improved flux-lock type superconducting fault current limiter(SFCL) is composed of a series transformer and superconducting unit of the YBCO coated conductor. The primary and secondary coils in the transformer were wound in series each other through an iron core and the YBCO coated conductor was connected with secondary coil in parallel. In this paper, we investigated the current limiting characteristics through initial line current after fault initiation. through the analysis, it was shown that the smaller initial line current is superior to current limiting characteristics and a point of view of power burden of the YBCO coated conductor.

• Journal of IKEEE
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• v.16 no.1
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• pp.1-6
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• 2012

Thermal rating or lifetime evaluation for aged overhead transmission line becomes more important concerns with respect to keeping power delivery stable having proper capability. Both load rating and dip/clearance are essential factors to determine transmission capacity. In order to evaluate thermal rating and conductor lifetime for domestic transmission lines with double-circuit, the dip/ground clearance standards as well as the electrical equipment technical standard are examined. Conductor temperature and dip are calculated under the assumption of a contingency, and then, a method to up-rate load capacity is searched. As thermal rating and limit dip for aged conductor are properly evaluated, an improved strategy in order to guarantee the existing power system reliability is presented in this paper.

• International journal of advanced smart convergence
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• v.8 no.2
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• pp.155-161
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• 2019

We introduces a mobile robot that can navigate on a power transmission line arranged in bundled conductors. The designs of the proposed robot are performed for navigation on bundled conductors, and the navigation method for bundled conductors and obstacle avoidance are presented. The robot consists of 13 degrees of freedom (DOF) with a symmetrical structure for the left and right parts, including the four wheel joints. The navigation method is designed using a combination of three motion primitives such as linear motion of counterbalancing box, linear motion of robot arm, and rotational motion of wheel part. To examine the performance of the proposed robot, navigation simulations are conducted using $ADAMS^{TM}$. The robot navigations were simulated on obstacle environments that consisted of two- and four-conductor bundles. Based on the simulation results, the performance of the proposed robot was reviewed through the analysis of the trajectories of end-effectors. We confirmed that the proposed robot was capable of achieving optimal navigation on bundled conductors that included obstacles.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.128-133
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• 2003

In this paper, we have proposed a method by using virtual simulation to calculate the behaviors of spacers to avoid conductor galloping with the hanging composite polymer spacer between conductors on different phases. We have considered with three types of modeling considerations for the analysis of galloping in power transmission lines, such as iced-single conductors without spacer, iced-single conductors with spacers, and iced-two bundle conductors with spacers. In simulation, the finite element method is used to calculate the structural response with geometric nonlinear behavior. The iced conductor is modeled by two beam-element faces with which it is connected. The ANSYS program is applied too. First, the calculation results show that the two beam-element model is very suitable to make a virtual simulation. Second, the amplitude of conductor galloping is reduced after hanged spacers. Third, when number of spacer is increased, the maximum magnitude of natural frequency of iced conductor will reduce. Final, the behaviors of spacers are verified in viewpoint of standard cases.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.5
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• pp.873-877
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• 2016

This paper proposed the structure that applied superconductors to the neutral line of a transformer and applied the normal conductors to the third line. The superconductor applied to the neutral line of a transformer limited the peak value of initial fault current, while the normal conductor finally limited the fault current. In order to secure the operating reliability of transformer type Superconducting Fault Current Limiter (SFCL) of previously proposed structure, we analyzed the operating characteristics according to the fault types. We tested a line-to-ground fault and a line-to-line fault. As a result of the experiment, all the faults showed that the superconductor stably limited the peak-value of initial fault current. Also, the normal conductor finally limited the fault current. Based on this research results, We thought that if the structure of inserting superconductor into the neutral line is applied to the real system, it could improve the reliability and stability of the power system.