• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07a
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• pp.398-401
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• 2002

When the current flows over the allowable current due to the overload, it causes electric disaster such as an electrical fire and an electric shock by short current or leakage of electricity because the covering is deteriorated according to the heating action. In this paper, for the wire(IV 1.6mm) used as interior wiring, we analyzed a variation of the surroundings temperature, the form and the structure of a covering, and the crystal structure of a conductor. In the result of this experiment, the surroundings temperature at the allowable current of 300% rose to about 47$^{\circ}C$, and it rose up to the maximum allowable temperature of the wire at 400%. Consequently, it was broken within one minute at 500%. In the analysis of a metallograph, the conductor broken by the over current showed the dendrite. These analyses result will be applied to judging the electrical fire.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.4
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• pp.615-620
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• 2017

In this study, we have developed the resistive leakage current detecting and tripping circuit breaker based on a 32bit ARM processor. The developed leakage circuit breaker can be operated in a desired trip threshold within 0.03 seconds as specified in KS C 4613. This resistive leakage current breaker is expected to be applicable as a circuit breake for prevention of electric fires and electric shock in smart distribution panel.

• Journal of the Semiconductor & Display Technology
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• v.17 no.3
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• pp.104-107
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• 2018

In this paper, we developed a sensor for monitoring the leakage current through the chassis of the robot. The leakage current sensor needs to be developed because it is a necessary part to prevent electric shock accidents that may occur through the chassis of a robot or an electric vehicle. This leakage monitoring sensor was developed to be mounted directly on the chassis of the robot. This sensor protects the control system from noise by discharging static and high-frequency noise that may occur in the chassis of the robot and monitors the leakage current by measuring the amount of current discharged through the ground. In this paper, a leakage monitoring sensor was developed with a simple structure using resistors, capacitors and OP-AMP, and the performance was evaluated.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.866-867
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• 2011

As part of the green growth, The Green Car has attracted wide attention. Types of the Green Car are Electric Vehicle, Plug-in Hybrid Electric Vehicle, Hybrid Electric Vehicle, Fuel Cell Vehicle and Clean Diesel Vehicle. Of these, The electric vehicle is equipped with the BDU(Battery Disconnecting Unit). BDU is supplying stable battery power and blocking it to protect electrical system of the electric vehicle. The BDU consists of electric components such as current sensor, fuse and pre-charge resistor. These must pass Voltage withstand test, Salt mist test, Thermal shock test, Vibration test and Short-circuit test commonly to verify reliability of the electric components. In addition, The current sensor should be verified whether normal operation. The breaking capacity of fuse should be verified. The durability of pre-charge resistor should be verified by supplying battery power and blocking it repeatedly. The reliability of BDU as well as the electric vehicle is secured by verifying the reliability of electric components. In addition, It will contribute to the acceleration and promotion of Green Car Technology.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2005.05a
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• pp.214-217
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• 2005

To improve the safety of facilities and human beings when the ground fault occurs, public power utility prescribes the reasonable ground resistances, measures and controls the ground resistance of all the ground electrodes biennially. Concerning the safety of human, there are two safety criteria widely accepted, i.e. the IEEE Std 80-2000 and the IEC 479-1:1994. The IEEE Std 80-2000 is based on a simplified electric shock model usually translated into permissible touch and step voltages. The IEC 479-1:1994 is less specific than IEEE Std 80-2000 for analysis purpose. The IEC 479-1:1994 provides values of permissible body current against electric shock duration. This paper provides a technical study of these two standards to analyze the safety of human beings of ground electrodes developed recently for distribution power system.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.2
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• pp.198-207
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• 2008

The conventional Residual Current Protective Devices(RCD, or earth leakage circuit breaker, ELB) operates depending on the total leakage current which is the vector-sum of resistive and capacitive components of a leakage current. However, the electric disaster such as electric shock or fire is mainly caused by the resistive component. Therefore, in this view point, the RCD is more realistic when it operates by the resistive component of the leakage current. In this paper, a new algorithm for measuring the resistive leakage current from the total leakage current is suggested, and is realized to an actual circuit. According to the suggested algorithm, the resistive component of the leakage current can be found by integrating the total leakage current over only a half cycle of the line voltage, and it is realized by using analog switches and resettable integrators. It is confirmed through experiments that the suggested algorithm detects, within maximum average error of 6.74%, the resistive leakage current from the total leakage current, and the RCD employing the suggested algorithm brakes the circuit within the regular interrupt time(30msec).

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.917-918
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• 2007

The former earth leakage breaker is operating by total leakage current which is the vector-sum of resistive leakage current and capacitive leakage current. However, the electric disaster like the electric shock and fire is caused mainly by resistive leakage current. Therefore, the earth leakage breaker is ideal when it is operating by resistive leakage current. In this paper, the theory for finding the component of resistive leakage current from total leakage current is suggested and it is embodied to actual circuit. The resistive leakage current can be found by integrating the total leakage current during half cycle of line voltage. Thus, we can simply find resistive leakage current by using OP-AMP integrators, and we can confirm that the resistive leakage current is computed exactly from total leakage current obtained by resistive leakage current and capacitive leakage current. The results that the earth leakage breaker is operating within regular interrupt time are verified when the former earth leakage breaker's controller circuit is replaced by the proposed controller circuit.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.9
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• pp.14-19
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• 2014

Recently, many renewable energy generating businesses are ongoing progress due to the introduction of the RPS(Renewable Portfolio Standards) as well as the needs of environmentally friendly energy resources. Researches on photovoltaic system are actively being processed since the photovoltaic system is relatively easy to install and becomes commercialized in many domestic application areas. Furthermore, the floating photovoltaic system is likely to be installed more actively since the conventional photovoltaic system requires relatively large areas of land. Also, the floating photovoltaic system is more efficient than photovoltaic system installed in land due to the operation in lower temperature. However, safety problems such as electric shock could arise since the cable should be installed in the water. In this paper, the leakage current and the voltage rising are measured and analyzed for the case when the cables are damaged connecting the floating photovoltaic system to the grid.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.58 no.3
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• pp.351-356
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• 2009

In this study, we analyzed and experimented about electric continuity for human body safety from green cars. And we compared power systems of HEV and examined about human body effect of current and time. We investigated internal and external standards and regulations for human body safety from high voltage electrical equipments. Indirect contact refers to contact between the human body and exposed conductive parts. According to UNECE R100, ISO 23273-3, ISO 6469-3 and Japanese Regulation Attachment 101, electric continuity between any two exposed conductive parts shall not exceed $0.1{\Omega}$. The value of electric continuity was measured below $0.1{\Omega}$ at the actual condition of green car. We expected that the results of these experiments can utilize to data for electrical safety of green car.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.50 no.7
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• pp.331-337
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• 2001

With the increasing reliability of analysis schemes and the dramatically increased calculating speed, the computer simulation has become and indispensable process to predict the interruption capacity of circuit breakers. Generally, circuit breakers have to possess both the small current and large current interruption abilities and the circuit breaker designers need to evaluate its capacities to save the time and the expense. The analysis of small current and the large current interruption performances have been considered separately because the phenomena occurring in a interrupter are quite different. To analyze the dielectric recovery after large current interruption many physical phenomena such as heat transfer, convection and arc radiation, the nozzle ablation, the ionization of high temperature SF(sub)6 gas, the electric and themagnetic forces and so forth mush be considered. However, in the analysis of small current interruption performance only the cold gas flow analysis needs to be carried out because the capacitive current is to small that the influence from the current can be neglected. In this paper, an empirical equation which is obtained from a series of tests to estimate the dielectric recovery strength has been applied to a real circuit breaker. The results of analysis have been compared with the test results and the reliability has been investigated.