• Proceedings of the KIEE Conference
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• 1997.07a
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• pp.77-79
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• 1997

An induction watthour meter was designed for use on circuits in which the voltage and current are essentially sinusoidal. As the application of switching devices has been increased, the waveforms of voltage and current have involved the harmonics. Therefore, power energy involving voltage and current with the harmonics is supplied to the system and the registration error of watthour meter is existed. In this paper, we experimented on the error of watthour mesurement under the sinusoidal and nonsinusoidal input source.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.138-138
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• 2022

Understanding a stream's or river's discharge is essential for a variety of hydrological and geomorphological applications at various sizes. However, depending on the stream environment and flow conditions, it is crucial to use the appropriate techniques and instruments. This will ensure that discharge estimations are as reliable as possible. This study presents developed smart system for continuous measurement of open channel discharge and evaluate streamflow measurement over various techniques. This includes developed smart flow meter as flow point measurements, smart water level sensor (installed on Hydraulic Structure ? Weir) and current meters. Advantages and disadvantages of each equipment are presented to ensure that the most appropriate method can be selected. we found that smart water level sensor is more prominent once used during flood event as compared to smart flow meter and current meters, while current meters seems to show better accuracy once applied for open channel.

• Journal of the Korean Society for Railway
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• v.10 no.6
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• pp.645-649
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• 2007

Ground systems flow fault currents into the ground, and suppress Ground Potential Rise (GPR) by the current. In this paper, we designed and fabricated a surge impedance meter to analyze the ground impedance in wide frequency ranges. The meter consists of a surge generator, a high speed sample/hold (S/H) circuit and an associated electronics. The surge generator produces surge voltage up to 5kV in ranges of $50\sim500ns$. Field tests were carried out to evaluate the surge impedance meter at a driven-rod ground system. The results showed that surge impedance of ground systems should be measured by various fast surge waveforms, since the impedance increases as the rise time of applied voltage increases.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.11a
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• pp.472-475
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• 2002

A Rogowski coil can measure alternating currents from a few amps to over 1 million amps in a frequency range from less than 0.1 Hz to about lMhz. A Rogowski coil provides an induced output voltage which is proportional to the rate of change of the primary current enclosed by the flexible or the rigid coil-loop. Therefore, it is necessary to integrate the output voltage in order to produce a voltage proportional to the current. Also. it can reproduce the current waveform on an oscilloscope or any type of data acquisition device. This paper describes the practical design of the combination of a Rogowski coil and an integrator which provides a versatile current measuring system to accommodate a wide range of frequencies, current levels and conductor sizes.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.14 no.11
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• pp.912-916
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• 2001

Fluxmeter is a measuring instrument the magnetic flux intensity by means of an integration of the voltage induced to a search coil to unit time. It also is required to a precise integrator since the voltage induced to a search coil has a differential value of the flux ${\Phi}$ to unit time. In this study, a bias current which is a main problem of the integrator in a drift troublesome depending on the temperature of a FET is investigated. We have confirmed that the temperature dependence of both the bias current of a integrator using the FET and the reversal saturated current of the minor carrier in a P-N junction of a semiconductor were the same. The property of a commercial integrator goes rapidly down with increasing temperature. The bias current of a FET is increased twice as much with 10$^{\circ}C$ increment. As a result, the low drift integrator could be developed by setting the lower temperature up with a pottier device.

• International Journal of Advanced Culture Technology
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• v.3 no.1
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• pp.113-119
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• 2015

This paper presents a design and implementation of real time electrical energy computing tool to measure and record the electrical energy based on type of detection devices, Hall Effect current sensor and Microcontroller. The tool was installed on the system power supply of the room and compared with kWh meter. Finally, we found that the energy record has error of average power calculating results is 0.077%.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.11a
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• pp.449-450
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• 2008

• Proceedings of the KIPE Conference
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• 1998.10a
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• pp.575-580
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• 1998

A power meter is an instrument for measuring in watts the power flowing in a electric equipment. Since the value which a conventional power meter measures is analog, the power meter is hard to determine a phase difference between the voltage and current for a inductive load. The phase difference causes a loss of electric power and a increase of power-line load. In this paper, we propose a digital power meter using TI's DSP(Digital Singnal Processor) TMS320C5x, which is employed to calculate the phase difference and more accurate power consumption.

• Journal of Sensor Science and Technology
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• v.19 no.6
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• pp.475-482
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• 2010

Rogowski coil which detects magnetic flux on current changes. It is used for digital integration with watt-hour meter's current sensor, because, Rogowski coil has non-cored or non-magnetic core structure, so that, it cannot be saturated magnetically. This is a study for inventing accurate electric current sensors that have been applied on multi-layer ceramic substrate. We have confirmed its properties from each different layer's materials and pattern sizes by MWS 3D Electromagnetic field analysis program. And, after sensor manufacturing on multi-layer ceramic substrate, we confirmed its sensing quality is reliable as accurate electric current sensor for watt-hour meter.

• Journal of the Korean Society of Safety
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• v.27 no.6
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• pp.48-53
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• 2012

This paper is purposed to develop portable electric instrument to select NI-9223(National instrument comp.) and clamp meter(HIOKI comp.), which can be used in developing electric instrument, to detect leakage current(ZCT) and current(CT) signals. In this paper, The electric instrument that can interface with current and leakage current instrument(HIOKI 9283), is developed by NI-9223 of NI comp.. HIOKI clamp meter can measure current signals certainly by high-sensitivity of 10 ${\mu}A$ resolution(leakage current : at 10 mA range) and current 1~200A range. The NI-9223 use four 16-bit analog-to-digital converters(ADCs) for true simultaneous sampling at up to 1 MS/s per channel. NI-9223 can synchronize all analog input modules installed in the same chassis to share the same start clock and/or sample clocks. The monitoring program is developed by SignalExpress of LabVIEW. The monitoring program are developed to analyze at simultaneous sampling on electrical signals such as leakage current(ZCT) and current(CT). The developed system verification tests were conducted, and portable electric instrument can be used in place which requires analysis of the actual electrical signal.