• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.2
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• pp.137-143
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• 2010

Complete dryness inside the stator is a necessary and sufficient condition for the leak test. Microcracks caused by high cycle fatigue due to operation are generated in stator windings, and they are interrupted by water molecules during the leak test. For this reason, during leak test, the wrong value is indicated when there are no leaks in stator windings. Generator manufacturers presents unique dryness judgment criteria for the leak test, but there is no actual criterion that accurately indicates the dryness point for the leak test. The reason is because stator winding has a complex structure and the absence of effective dryness equipment in power plants. This paper proposes a dryness judgment criterion to evaluate if inside the stator winding is dried completely and presents experimental results.

• Transactions of the Korean Society of Automotive Engineers
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• v.19 no.1
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• pp.73-81
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• 2011

The performance of emission factor has been validated by comparison with on-road test data. Emission factor, which is a function of vehicle speed, has been acquired based on chassis dynamometer test with NIER driving pattern. Portable Emission Measurement System, PEMS has measured on-road emission. Test vehicle was operated on defined test routes under different driving conditions, and made ten trips along its route. Emission factors properly simulate on-road test result, although there is some drawback to consider variety of driving condition on real world. Vehicle specific power and acceleration have been used to explain the distributed on-road result within same vehicle speed range. The trend in carbon dioxide and nitrogen oxide emission with respect to specific power and acceleration is clear. It has been found that specific power is a good explanatory variable for microscopic analysis for modal test result. Acceleration is good for microscopic as well as macroscopic analysis.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.6
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• pp.683-691
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• 2011

In order to develop technology for an equipment qualification (EQ) test, which is an important process in localizing solenoid-operated valves used in nuclear power plants, we analyzed related regulations, test procedures, conditions, equipment, and acceptance criteria. EQ regulations for the solenoid-operated valve are classified as law, guide, and standard, and are subdivided according to test specimens and contents. The EQ test is composed of functional, normal-, and accident- condition tests. The solenoid-operated valve is aged under normal and accident conditions, which are predicted in the design conditions of a nuclear power plant, and the performance of the valve is measured by a functional test. The test method and procedure analyzed in this paper might be very useful for manufacturers as well as EQ testers.

• Journal of the Society of Disaster Information
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• v.13 no.3
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• pp.358-365
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• 2017

As the damage caused by disasters increases rapidly around the world, it is necessary to develop the technology for equipment to reduce human injury. Therefore in the support of fire safety and 119 rescue and rescue technology research and development project, in the "Development of a power assist device for a fireman to rescue humans(2015 ~ 2018)" for life saving restoration, we are developing equipment that satisfies the lifting performance considering the disaster environment and the disaster response scenario(Amount of load over 100 kg, height of over 1 m, height over middle 60 cm, speed over 0.2 m/s). In this study, we propose a lifting performance and environmental test method to evaluate the usefulness of the power-assisted device and analyze and verify detailed specifications of the device through dynamics analysis of the lifting performance test. This study suggests that the proposed test method can be applied practically to evaluate whether a stable performance of a power-assisted device is achieved.

• New & Renewable Energy
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• v.5 no.3
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• pp.4-12
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• 2009

The effect of change in DFIG (doubly-fed wind power generator) rotating speed and active power on the grid was analyzed to understand the characteristics of wind power using the wind power simulator connected to the grid at Gochang Power Quality Test Center. Electric power quality improvement devices (DVR, STATCOM, SSTS) and electric power quality disturbance application devices for 22.9 kV grid are equipped at Gochang Power Quality Test Center. Induction motor and VVVF inverter were used to emulate the blade of a wind power generator, and a simulator for Cage wound induction generator and DFIG was developed. The trial line were assumed to be 20 km and 40 km in length, and variable wind speed pattern was set using wind speed data from Ducjeokdo to verify the power characteristics of the wind power generator according to rotating speed.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.8
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• pp.1572-1579
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• 2009

In this dissertation ultra-broadband power amplifier(UPA) was designed and fabricated using negative feedback technique. UPA was made of pre-amplifier, drive amplifier and power amplifier. Negative feedback technique was used to achieve ultra-broadband performance. Designed power amplifier has 30dB gain and 2W output power. The load-pull data of power amplifier for optimal power matching was extracted from the measured S-parameter. Fabricated PCB material, permittivity is 4.6 and thickness is 0.8mm, is FR4 and UPA was fabricated 3 modules for comparison of the simulated and measured results. Size of the fabricated pre-amplifier and drive amplifier module is 40mm'50mm'16mm. And from the experimental results, gain of the pre-amplifier module is 9.87dB at 2GHz and flatness is 0.63dB. Experimental result of the drive amplifier module is 10.97dB at 2GHz and flatness of that is 0.26dB. Test result of the power amplifier module is 10.71dB at 2GHz and flatness is 0.72dB. Total size of the power amplifier is 45mm'134mm'16mm. According to the test results, gain of the UPA is 28.98dB at 2GHz and flatness is 1.68dB. Output power was 32.098dBm at 2GHz, 32.154dBm at 1GHz and 31.273dBm at 100MHz.

• Journal of Power Electronics
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• v.11 no.4
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• pp.471-478
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• 2011

This paper addresses the establishment of a kVA-range plug-in hybrid electrical vehicle (PHEV) integration test platform and associated issues. Advancements in battery and power electronic technology, hybrid vehicles are becoming increasingly dependent on the electrical energy provided by the batteries. Minimal or no support by the internal combustion engine may result in the vehicle being occasionally unable to recharge the batteries during highly dynamic driving that occurs in urban areas. The inability to sustain its own energy source creates a situation where the vehicle must connect to the electrical grid in order to recharge its batteries. The effects of a large penetration of electric vehicles connected into the grid are still relatively unknown. This paper presents a novel methodology that will be utilized to study the effects of PHEV charging at the sub-transmission level. The proposed test platform utilizes the power hardware-in-the-loop (PHIL) concept in conjunction with high-fidelity PHEV energy system simulation models. The battery, in particular, is simulated utilizing a real-time digital simulator ($RTDS^{TM}$) which generates appropriate control commands to a power electronics-based voltage amplifier that interfaces via a LC-LC-type filter to a power grid. In addition, the PHEV impact is evaluated via another power electronic converter controlled through $dSPACE^{TM}$, a rapid control systems prototyping software.

• Nuclear Engineering and Technology
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• v.29 no.6
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• pp.488-499
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• 1997

The measurements of the moderator temperature coefficient (MTC) are performed to demonstrate that the calculational model produces results that are consistent with the measurements. Since negative MTC is also a technical specification value that may limit the cycle length, it is important to measure it as accurately as possible. In this report, preferred choice of test method depending on the time in cycle, best power indication and temperature definition in MTC calculation were determined based on the MTC test results taken during initial startup testing and at 2/3 cycle burnup in the Yonggwang nuclear power plant. The results show that the ratio and rodded methods provided good agreement with the predictions during initial startup testing. However, near end-of-cycle the depletion method gives better results, and so is suggested to be used in the MTC measurements at 2/3 cycle burnup. The use of primary Delta T power as a power indicator in the MTC calculations is highly advisable since it responds with good consistent results very quickly to changes unlike secondary calorimetric power. For the appropriate temperature definitions used in the MTC calculations, it is considered that the arithmetic average temperature measured simply by inlet and outlet thermocouples is preferred. Although volumetric average temperature provides better results, the improvement is not sufficient to compensate for the simplicity of calculations by arithmetic average temperature.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.772-776
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• 2011

EAV-2, which has a solar cell, fuel cell and battery as its power sources, is under development by KARI. Electric power sources are selected through voltage matching without power converter and controller and tested. The ground integrated test for integrated system is performed during 5 hr. it is confirmed that battery's power response is faster than other power sources at starting and transient condition, fuel cell and solar cell are a major electrical power during cruise condition. It is revealed that the used energy portions of fuel cell, solar cell and battery are 68%, 29%, 2.5% respectively.

• Journal of Power System Engineering
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• v.11 no.3
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• pp.35-40
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• 2007

Leak would happen because of the damage of high temperature and high-pressure valve in nuclear power plant. condition based prevention maintenance is essential by using the suitable method based on local condition. Energy loss prevention can prevent from an accurate test, Local actually and ability. The methods of test for high energy fluid leak at present are analysis of ${\Delta}T$, AE(Acoustic Emission) analysis, and thermal image. The result for test of secondary system in nuclear power plant Unit reveals that the AE occurred clearly in leakage situation, but thermal image didn't occur. It is identified that leak is occurred when the orifice located front and back of valve operates. It shows that making a impatient judgment by using the single method if it is leakage is containing uncertainty. So we think that using the Multi-Measuring method is more sound judgment than single-measuring method.