• Journal of the Korean Society of Industry Convergence
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• v.9 no.1
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• pp.67-72
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• 2006

This study is on the development of algorithm of surge test for quality control on electrical parts of throttle body in automobiles with internal combustion engine, not only to know its condition to be good or not, but also jugding its condition to be classified into six types. To know whether its condition to be good or not, comparing and analyzing between two waveforms generated from master and test coil of throttle body. If test net area is below 20% of master area, the condition of test coil is good. By analyzing test coil waveform to master coil waveform, the condition of test coil into winding badness, insulation badness, layer and corona discharge, short badness should known. Therefore quality control system on electrical parts of throttle body should be developed.

• Journal of the Korean Magnetics Society
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• v.26 no.5
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• pp.154-158
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• 2016

A CRDM (Control Rod Drive Mechanism) is an electromagnetic device which drives a control rod assembly linearly to regulate the reactivity of a nuclear core. An RPIS (Rod Position Indication System) is used as a position indicator for a control rod assembly of a CRDM of SMART, and an RPIS consists of permanent magnets and reed switches. SMART is designed for the maximum coolant temperature of $350^{\circ}C$, and the permanent magnets are installed inside of the reactor. The reed switches and electrical circuit are installed outside of the reactor on the other hand. Test coil for a reed switch is test equipment for quality verification of a reed switch, and a test coil consists of a coil and core. In this study, magnetic property of test coil and permanent magnet on a reed switch is compared by using finite element electromagnetic simulation.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.52 no.11
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• pp.557-562
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• 2003

To develop a stable and compact small-sized superconducting magnetic energy storage (SMES) system, which provides electric power with high quality to sensitive electric loads, we fabricated a SMES coil and tested it. Because such a large-sized superconducting coil quenches far away from its critical current, the recovery current is frequently used as a stability criterion in the coil fabrication. Therefore, we first investigated the recovery current characteristics of the large current conductor, which was used in our SMES coil fabrication. The test results indicate that the recovery currents measured in the conductor are nearly identical to those based on the single wire. This implies that the recovery current is affected by the conductor's cooling condition rather than its size and current capacity. In the SMES coil test the first quench occurred at 1250 A, which is equivalent to the stored energy of about 2 MJ. It corresponds to the quench current density of about $130A/mm^2$ This value is much higher in comparison with that reported in the other work. In addition, the first quench current of the coil agrees well with the measured recovery current of the conductor having similar cooling condition with it. This means that to determine the recovery current of a conductor is, first of all, important in the design and fabrication of a large-sized superconducting coil.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.9
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• pp.1656-1662
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• 2011

In a previous paper, the EMTP modeling technique using search coil test is established through various transient analysis including system grounding condition and grounding resistance for HVDC submarine cables. It was also proved by comparison with real test results. Based on this EMTP modeling technique, in this paper, it will be applied for modeling of ${\pm}180kV$ real HVDC submarine system(Jeju~Haenam). This paper variously analyses the effects of fault resistance including the resistance between core and sheath, the resistance between sheath and amore and the resistance between amore and sea water through EMTP modeling of search coil method. The results can contribute to the accuracy of detailed fault point prediction of search coil test for HVDC submarine cables.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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• 2003.10a
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• pp.307-310
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• 2003

The KSTAR (Korea Superconducting Tokamak Advanced Research) prototype TF (Toroidal Field) coil was tested in the superconducting coil test facility in KBSI (Korea basic Science Institute). The test was divided into several campaigns according to the objectives. The objectives of the first campaign were to cool the coil into operating temperature and to find any defect in the coil such as cold leaks. From the results of the first campaign, which was carried out during Jan. 2003, any defect in the TF prototype coil was not found. At the second campaign, the large-current charging experiment was one of the major issues, and was carried out during Aug. 2003 In this paper, the test preparation, and the test results of the second campaign were presented.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.943-944
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• 2007

In this paper, the development and the test of 13.2kV/630A high-Tc superconducting fault current limiting coil are described. The fault current limiting coil made of Coated Conductor (CC) was fabricated with bifilar winding method for non-inductive characteristics and tested in the distribution power system level in Dec. 2006. In order to determine the length of the superconducting coil, applied voltage per unit length(V/m) was studied analytically and it was verified through experiments. For the volume minimization, the coil was designed with concentrical arrangement method. The short-circuit test was performed with the prospective fault current of asymmetrical 10kA whose maximum fault current was $30kA_{peak}$. In the test, the voltage drop and the current of the coil were measured and the resistance of the coil was obtained. Also, the temperature rise of the coil was calculated with the relationship between the resistance and the temperature of CC. In this paper, the experimental results are analyzed and compared with the simulation.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.9
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• pp.1593-1599
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• 2010

This paper describes the EMTP modeling method using searching coil test for HVDC submarine cables. HVDC submarine cables consist of conductor, lead sheath and amore. It is different from general cable which is composed with just conductor and aluminium sheath. Therefore, the transient characteristics are totally different between HVDC submarine cable and general cable. However, the study on HVDC cable modeling and transient are insufficient. In this paper, EMTP modeling is performed according to grounding interval and grounding resistance, then they are compared with real test results by searching coil test.

• Transactions of Materials Processing
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• v.23 no.7
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• pp.431-438
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• 2014

For electromagnetic forming(EMF) the most important feature is a forming coil which creates the electromagnetic force(Lorentz force), using current density and a magnetic field. Most previous papers have concentrated on the final configuration of the blank or the efficiency of EMF process. Studies focused on the design parameters affected by the forming coil performance have not been conducted. In order to design a suitable forming coil for an object, the current study uses LS-DYNA EM-Module to not only optimize the coil but also to examine the effect of coil performance. By this method a suitable forming coil was made and tested to determine whether or not good formability was achieved in a free bulge test Numerical analysis was also used. The workpiece was Al 1100-O with a thickness of 1.27mm and the coil was made from copper CW004A, which has good electrical conductivity and is suitable for electrical components.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.9
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• pp.84-90
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• 2018

In constructing the multi-body dynamics model to analyze the behavior of the railway vehicle, it is very important to understand the properties of the suspension elements that constitute the suspension system. Among them, coil springs, which are mainly used in primary and secondary suspension systems, clearly show the axial stiffness in the drawings, but the lateral properties of the coil springs are not specified clearly, making it difficult to construct a dynamic analysis model. Therefore, in this paper, the model for analyzing the lateral stiffness of the coil spring is examined. A finite element method was applied to analyze the lateral stiffness of the coil spring and numerical analysis was performed by applying the coil spring lateral stiffness analysis model proposed by Krettek and Sobczak. And the test to analyze the lateral stiffness of coil spring was conducted. As a result of comparing with the test results, it was found that the results obtained by applying the lateral stiffness analysis model of Krettek and Sobczak and correcting the correction coefficient are similar to those of the test results.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.48 no.1
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• pp.13-18
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• 1999

To fabricate a 0.7 FJ, 100 kVA $\mu$SMES device for improving power quality in sensitive electric loads, we developed a design code for a $\mu$SMES device and designed the 0.7 MJ $\mu$SMES device by using it. In this study special emphasis was placed in influence of winding tensions on quench currents of superconducting coils because dry superconducting coils are usually quenched by local disturbances due to strand motions. We first investigated the quench currents of a few kA class superconducting cables for various winding tensions experimentally. To prove the validity of the code and develop all techniques related to fabrication and test of the 0.7 MJ $\mu$SMES device, a smaller size superconducting coil was wound with high winding tension of about 15 kgf/$mm^2$ based on the test results of superconducting cables and tested. It isshown form the test results that designed parameters for the smaller size superconducting coil are in good agreements with measured ones and the quench current of the coil with high winding tension reaches nearly to the critical current of the superconducting cable without any training effects.