• Proceedings of the KIPE Conference
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• 2003.07a
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• pp.162-167
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• 2003

In this paper, systematization design method by analogical Interpretation which is profitable in the compatability and standardization of developed products and is useful of reducing construction time and price was introduced. Systematization design based on analogical interpretation is a method which systematizes each characteristic with mathematical description in order to make variable design parameters correspond with the terms desired. In this paper, after choosing a differential transformer as the sample for design components each characteristic was expressed mathematically by analogical interpretation and miniaturized ones were manufactured by similarity factors. The relationship between input voltages of an actual differential transformer and the model and output voltages occurred by the change of the displacements in operational axis was shown.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.1380-1383
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• 1996

This paper presents a recoil and counter recoil(R&CR) motion measurement method using linear variable differential transformers(LVDT). The output of a LVDT is obtained from the differential voltage of the 2nd transformers. As a sensor core is attached at the motion body, the output is directly proportional to the core motion. Displacement, velocity and acceleration are measure from the core length. With a comparison between the measurement result and the known value which is obtained by the precision steel tape, the accuracy and the usefulness of the proposed scheme is validated.

• Proceedings of the KIPE Conference
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• 1999.07a
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• pp.218-221
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• 1999

We introduce the systematization design method using similarity theory which is profitable in the compatability, the reduction of construction time and price. The design method can make us predict the characteristic experiment for the magnitude we desire as the expression equation applied continuously. We can induce the design sample the user demand with the verification of the data on optimum design previously. Therefore, in case of designing and developing the products, systematization design method is very useful for the standardization of the developed goods, compatability, the reduction of construction time and price. In this paper, we presented the analogical algorithms of systematization design using similarity theory, design factors and processing method of the restriction factors. Also, we analyzed the output voltage in terms of input voltage and displacement as choosing a differential transformer as the model.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.49 no.9
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• pp.578-583
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• 2000

We introduce the systematization design method using analogical analysis. The design method can make us predict the characteristic experiment for the magnitude we desire as the expression equation applied continuously. We can induce the design sample the users demand with the verification of the data on optimum design previously. Therefore in case of designing and developing the products systematization design method is very useful for the standardization of the developed goods compatability the reduction of construction time and price. In this paper we present the analogical algorithms of systematization design using similarity theory design factors and processing method of the restriction factors. Also we analyze the output voltage in terms of input voltage and displacement as choosing a differential transformer as the model.

• Journal of Institute of Control, Robotics and Systems
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• v.3 no.5
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• pp.455-460
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• 1997

This paper presents a recoil and counter recoil motion measurement method using linear variable differential transformers(LVDT). The output of a LVDT is obtained from the differential voltage of the 2nd transformers. As the sensor core is attached to the motion body, the output is directly proportional to the core motion. Displacement, velocity and acceleration are measured from the core length. A comparison between the measurement result and the known value, which is obtained by the precision steel tape, shows that the accuracy and the usefulness of the proposed scheme is validated.

• Journal of Institute of Control, Robotics and Systems
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• v.6 no.1
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• pp.51-56
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• 2000

This paper presents the characteristics of the dynamic response and calibration technique on a linear variable differential transformer(LVDT). The linear error of the LVDT was proven $\pm$1% in the static calibration and $\pm$0.5% in the dynamic calibration. In this paper, the linearity error generated in the static and dynamic state of the core movement can be eliminated using the correction algorithem of the static and dynamic state derived from the least square linear approximation for the nonlinearity of the curves of direct data fitting and Lagrange polynomials. With the static and dynamic calibration method, the calibration accuracy of the LVDT can be reduced to within $\pm{0.5%.}$.

• Proceedings of the KIEE Conference
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• 2000.11a
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• pp.171-173
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• 2000

This paper presents a discriminating algorithm between magnetizing inrush and internal faults of transformers using difference of a differential current. Incase of inrush, change of magnetizing inductance repeats. Thus, second difference of differential current periodically shows pulse while periodic pulse is not represented in case of internal winding fault. The proposed algorithm is suitable irrespective of the amount of remanent flux.

• Journal of the Korean Society of Propulsion Engineers
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• v.3 no.4
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• pp.12-22
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• 1999

Operation of an electromagnetic shaker system using a Class-D amplifier may cause unacceptable electromagnetic interference to another electronic system, requiring the user to take whatever steps are necessary to correct the interference. A differential amplifier in a Class-D amplifier is used to decrease the effect of a common-mode noise voltage in a shaker system. To prevent a ground loop, a transformer is inserted in another shaker system. These methods show reduction of the unwanted vibration which has occurred before. A transformer in a charge amplifier was used to prevent a ground loop in a shaker system using a Class-AB amplifier a few years ago, but it was susceptible of noise in a shaker system using a Class-D amplifier. Hence we corrected a ground loop between a charge amplifier and a vibration control/analysis system without a transformer. The usefulness of this approach is illustrated by the results of experiments.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.760-761
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• 2011

Ground differential relay is used to provide fast, sensitive, and selective protection for the wye connected and grounded electrical power equipment such as generators, power transformers, and grounding transformers. The ground differential protection only protects the ground faults within the protection zone, so that it can't protect the line-to-line fault. This paper proposes the algorithm to provide the protection for the line-to-line fault through the ground differential protection. The proposed algorithm detects the line-to-line fault of transformer using the comparison between the positive and the negative current, when the ground differential relay dose not operate. The performance of the algorithm is verified using a PSCAD/EMTDC simulator under various case studies.

• Proceedings of the KIEE Conference
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• 2005.07a
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• pp.444-446
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• 2005

This paper describes a current differential relaying algorithm for power transformers with an advanced compensation algorithm for the secondary current of CTs. The comparative study was conducted with and without the compensating algorithm. The algorithm can reduce the operating time of the relay in the case of an internal fault and improve security for external faults. The performance of the proposed algorithm was investigated when the C100 CT, a quarter of the rated CT(C400), is used.