• Nuclear Engineering and Technology
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• v.55 no.12
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• pp.4317-4328
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• 2023

To ensure the measuring accuracy of the wall temperature, the outer wall temperature measurement values by using three kinds of thermocouple welding methods were analyzed and evaluated in the paper, including single-point flush-mounted in the wall groove method, single-point insert-mounted in the wall groove, and outer surface direct welding method, based on the application of a tube-in-tube condensing heat exchanger. And the impacts of silver, tin, and thermal resistance adhesive as filling materials on wall temperature measurement were also investigated, and the results were compared to that obtained without filling materials. The results showed that the wall temperatures measured by the three welding methods were lower than the theoretically calculated value. And the wall temperature measured by the outer surface direct welding method was lowest under the same experimental conditions. The wall temperatures measured by single-point flush-mounted and insert-mounted in the wall groove methods were also affected by different welding filling materials. It was found that the greater the thermal resistance of filling materials, the smaller the heat loss. By analyzing the reasons for the low measured value of wall temperature, a new wall temperature measurement method was developed to improve the accuracy of the current measurement method. Meanwhile, the outer wall temperature measurement experiments of vertical and horizontal heat transfer tubes were carried out to validate and calibrate the improved outer wall temperature measurement method. The results showed that the average outer wall temperature deviation measured by the improved wall temperature measurement method ranged from - 0.82% to +2.29% for vertical tubes and - 4.75% to - 1.44% for horizontal tubes, and the improved measurement method had good measurement accuracy.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.9
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• pp.1560-1565
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• 2010

The renewable resource are getting more attentions with increased concerns on the depletion of fossil fuels and several environmental issues like emission problem. Wind power is a representative option among several renewable sources and the generation capacity using wind power is being increased. However, the wind generation is so volatile on its output characteristic, so it is required to assess the grid impact of wind power generation by measuring the fluctuation effect more precisely. This paper proposes the method for measuring the generation output according to IEC 61400-21(Measurement and assessment of power quality characteristics of grid connected wind turbines) to assess the power quality of wind turbine generation. In addition, it shows an application case to a small-scale wind power generator. In the case study, it suggests a structure design of the proposed measurement instrument both on hardware and software aspects, which is composed of a remote monitoring & data analysis program and an FPGA based real-time signal processing device.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.675-676
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• 2008

The computer based three phase power analysing system has been developed as a traveling standard for onsite power calibration. The system is utilized with digital-to-analog converts which were synchronized each other. Using digital signal processing technique the software has been developed to calculate power parameters. The calibration system is fully traceable to national standard system and, accuracy allows the calibration of industrial power measurement systems.

• The Transactions of the Korean Institute of Power Electronics
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• v.14 no.4
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• pp.261-267
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• 2009

Due to the measurement noise or system noise, the performance of photovoltaic power generation system can be degraded. If this noise is contained in the solar array voltage measurement signal, the correct operation of the maximum power point tracker can not be guaranteed. The application of the extended Kalman filter to the photovoltaic system can obtain enhanced states estimation result. The Kalman filter provides a recursive solution to optimally estimate from random noise signals. Additionally, as a consequence of Kalman filter, the unmeasurable state such as inductor current can be estimated without current sensor. The methods for system modeling and extended Kalman filter design are presented and the experimental results verify the validity of the proposed system.

• Journal of Electrical Engineering and Technology
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• v.7 no.3
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• pp.304-311
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• 2012

So far, the importance for an accurate load model has been constantly raised and its necessity would be further more emphasized. Currently used load model for analysis of power system in Korea was developed 10 years ago, which is aggregated by applying the statistically estimated load compositions to load models based on individual appliances. As modern appliances have diversified and rapidly changed, the existing load model is no longer compatible with current loads in the Korean power system. Therefore, a measurement based load model is more suitable for modern power system analysis because it can accurately include the load characteristics by directly measuring target load. This paper proposes a ZIP model employing a Kalman-filter as the estimation algorithm for the model parameters. The Kamlan-filter based parameter identification offers an advantage of fast parameter determination by removing iterative calculation. To verify the proposed load model, the four-second-interval real data from the Korea Energy Management System (K-EMS) is used.

• Journal of Sensor Science and Technology
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• v.18 no.1
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• pp.63-71
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• 2009

It is said that the desirable bio-signal measurement and stimulation system should be an implantable type if the several problems such as biocompatibility, electrical safety, and so on are overcome. In addition to the biocompatibility issue, a robust RF communication and a stable electrical power source for the implantable bio-signal measurement and stimulation system are very important matters. In this paper, a wireless telemetry system which adopts the FCC's approved MICS (medical implant communication service) protocol and a wireless power transmission has been proposed. The proposed system composed of a base station (BS) and an implantable medical device (IMD) has the advantages that the interference with other RF devices can be reduced by the use of the specially assigned MICS frequency band of 402.MHz to 405 MHz. Also, the proposed system includes various functions of a multi-channel bio-signal acquisition and an electric stimulation. Since the electrical power for the IMD can be provided by the inductive link between PCB patterned coils, the IMD needs no battery so that the IMD can be smaller size and much less dangerous than the active type IMD which includes the internal battery. Finally, the validity as a wireless telemetry system has been demonstrated through the experiments by using the implemented BS and IMD.

• Journal of Biosystems Engineering
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• v.17 no.4
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• pp.326-335
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• 1992

This study was carried out to develop a measurement and analysis system of ride vibrations of tractors. The system consists of a portable digital computer, a PCL-812 PG interface card for A/D conversion, two accelerometers, two signal conditioners, a DC-AC power inverter and a DC power supplier. The computer programs installed in the system for data acquisition and analysis were also developed. It was intended that the system should be cheap enough to be afforded by college laboratories but reliable in its functions of measurement and analysis. Characteristics of the components and methods used in the system development were discussed.

• Proceedings of the KIPE Conference
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• 2003.07a
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• pp.177-181
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• 2003

Need of power stability, reliability is increased, as using of sensitive: nonlinear load are increasing. Therefore, Power Quality Problems become the center of public interest. Many kinds of algorithms have been studied for monitoring of Power Quality Problems. Monitoring algorithms of using RMS, FT and the others are easy to applicate to system. But, it is not enough to monitor all of Foyer. Quality problems. Wavelet Transform is more proper to applicate. so, This paper presents measurement system using discrete wavelet transform.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.10 no.6
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• pp.118-125
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• 2011

In this paper, a WCDMA experimental base station is constructed for power management of mobile communication base station and effective isotropic radiated power is determined by using received power of pilot channel measured on the line-of sight. The measurement system was constructed by a experimental base station and a measurement receiver and the common pilot channel (CPICH) power of the base station was measured. Effective isotropic radiated power (EIRP) of the base station obtained by the measurement value considering correction factor for the errors represented the difference of 0.5 dB compared to the established EIRP of the base station.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.05a
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• pp.410-413
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• 2003

We have developed the measurement system for the high power laser The absorber is made of gold-plated copper cavity. The calibration heater is using a manganin(CuMn12Ni ; Isabellenhutte) coil, and output power is measured by using of resistance bridge with composed manganin and copper coil. Developed system can measure for 5∼1000w laser output power range. Calibration factors are 489.13 J/mV at 100W range and 489.13 J/mV at 500W range. Correction factors are 0.99 at 100W range and 1.006 at 500W range.