• Proceedings of the KIEE Conference
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• 2002.07c
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• pp.1413-1415
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• 2002

The Displacement current measurement system used in this experiment because detecting the dynamic behavior of monolayers at the air-water interface is possible. It basically consists of a film balance, a pair of electrodes connected to each other through a sensitive ammeter. Here, one electrode is suspended in air and the other electrode is placed in the water. PBLG phase transformation measured by Maxwell-displacement-current-measurement method in surface of the water. Measured (surfacc pressure, displacement current and dipole moment) of monolayers of PBLG on the water surface. We measured displacement current that occur when changed temperature(15, 20, 25$^{\circ}$ ) and the compression speed(30, 40, 50(mm/min)). From the result, it is known that curren generated in the range of high surface pressur compression velocity and temperature become faste.

• Journal of Sensor Science and Technology
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• v.4 no.3
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• pp.1-8
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• 1995

An electronically compensated current sensor for measurement of power is presented in this paper. An electronic technique which is proposed to design an improved current sensor by means of a feedback winding and an electronic compensation is described. A precision power transducer with a proposed current sensor has been constructed for testing and performance evaluation.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.05c
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• pp.47-50
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• 2001

Conventionally, air-cored Rogowski coil was designed for use as high alternating and transient current sensor without saturation caused by ferromagnetic material in its core. This paper investigated that Rogowski coil can be applied to low current measurement in 60Hz power line. Measured parameters R, L of coil were compared with theoretically calculated values. Output voltages crossed by Rogowski coil have shown some linearity according to input current(tens to thousands of amperes) passing through it. And also shielding effect for external noises was investigated for three cases.

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.801-803
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• 2000

The large scale magnets like thermalnuclear fusion devices are necessary for superconducting CICC cable, When the Cable In Conduit Conductors(CICC) is occurred by the external turbulence, the CICC occurs to quench, The CICC can be broken because the CICC spends all energy in the quench-happened spot. Therefore, it is necessary to develop measurement systems of the quench detection. The measurement systems of the relative good degree of efficiency are the voltage tap sensors. The weak points of voltage tap sensors are effected by EMF noise and inductance. The thermalnuclear fusion devices easily can't measure inductance value because of plasma current. In the experiment, The value of inductance was estimated by FEM techniques and the decrement of Inductance value measured as long as remaining plasma current.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.53 no.4
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• pp.213-217
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• 2004

A current transformer(CT) used for the estabilishment of high current national standard, has generally very small ratio error and phase angle error. Both the errors of CT depend critically on the external burden used. When both the ratio and phase angle errors at two different burdens including zero burden are known, those at any other burdens are calculated theoretically. The theoretical values are well consistent with the experimental results within the $82{\times}10$-6, implying the measurement system of CT in KRISS is well maintained.

• Proceedings of the KIEE Conference
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• 2009.04b
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• pp.201-203
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• 2009

This paper presents the real time stray current monitoring techniques on the DC railway system. These techniques are two types. The first one is the rail potential measurement technique between running rail and earthing mats on the important locations such as substation, station, and so on. And the second one is measurement technique of stray current through substation earthing mats and from collection mats, and continuous monitoring of return currents through the running rails. We need to apply these techniques on DC railway system to monitor stray current periodically and maintain the system properly.

• International Journal of Safety
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• v.5 no.2
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• pp.1-5
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• 2006

A data acquisition and processing system for measuring the current collection signals of the Korean High-speed Railway is developed. The current collection system is composed of a pantograph and the overhead catenary that supplies electrical power to the train through the pantograph. The system simultaneously measures the signals generated at the interface between the catenary and the pantograph through the accelerometers, load cells and strain gauges placed at various locations. The on-track test data are processed to evaluate the current collection reliability. The fiequency analysis of the signals reveals the presence of several structural vibration modes in the pantograph, as well as the components arising from the periodicity in the structure of the catenary and pantograph at the interface. The feasibility of predicting the contact performance from the measured signals is also demonstrated.

• Journal of Advanced Marine Engineering and Technology
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• v.32 no.8
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• pp.1257-1262
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• 2008

A long-distance remote sensing of temperature and current based on a fiber Bragg grating (FBG) is proposed and demonstrated. The thermal expanding effect of the epoxy and the Er-doped fiber ring laser (EFRL) are applied to the sensor system to enhance the temperature and current sensitivity. An EFRL with a 5 km-single-mode fiber and a FBG shows a high extinction ratio of more than 60 dB and a low power fluctuation of less than 1 dB. The metal wires are used to supply the current to the sensors. When the NOA65 puts on the FBG as a thermal expanding material, the temperature and current sensitivity of the lasing wavelength shift are about $30\;pm/^{\circ}C$ and 3pm/mA, respectively. The proposed sensing scheme is useful for measurement of current or temperature at a distant object of more than several km.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.659-660
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• 2010

• 한국초전도학회:학술대회논문집
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• v.11
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• pp.57-57
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• 2001