• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.6
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• pp.885-891
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• 2017

The energy storage system(ESS) is a core component for exchanging the power system structure of the unidirectional power flow into a bidirectional structure. Its important role has been increasing because it has multiple functions such as output stabilization of new renewable energy, demand management, frequency regulation, etc. However, the performance evaluation technology of ESS in korea is lower than one of advanced countries and the recognition of standardization is also lack compared to advanced countries. Furthermore, in order to more accurately and reliably validate the performance of the ESS in advanced countries, it has been required to perform not only performance testing by H/W devices but also performance verification by S/W tool. Therefore, in order to verify the performance testing of ESS by S/W tool, this paper proposes the modeling method of performance testing devices for MW scaled ESS by using the PSCAD/EMTDC S/W, based on real testing devices in domestic institute. From the simulation results of proposed modeling method, it is confirmed that the proposed modeling method is a useful tool for performance validation of ESS.

• Journal of Power Electronics
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• v.9 no.4
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• pp.575-581
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• 2009

In this paper two modes of operating a wound rotor induction machine as a generator at sub-and super-synchronous speeds in wind energy conversion systems are investigated. In the first mode, known as double fed induction generator (DFIG), the rotor circuit is fed from the ac mains via a controlled rectifier and a forced commutated inverter. Adjusting the applied rotor voltage magnitude and phase leads to machine operation as a generator at sub-synchronous speeds. In the second mode, the machine is operated in a slip recovery scheme where the slip energy is fed back to the ac mains via a rectifier and line commutated inverter. This mode is described as double output induction generator (DOIG) leading to increase the efficiency of the wind-to electrical energy conversion system. Simulated results of both modes are presented. Experimental verification of the simulated results are presented for the DOIG mode of operation, showing larger amount of power captured and better power factor when compared to conventional induction generators.

• Nuclear Engineering and Technology
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• v.38 no.2
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• pp.185-194
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• 2006

Transient operations for an integral type reactor, SMART-P, have been experimentally investigated using a thermal-hydraulic integral test facility, VISTA (Experimental Verification by Integral Simulation of Transients and Accidents), in order to verify the system design and performance of the SMART-P, a pilot plant of SMART. The VISTA facility was subjected to various accident conditions such as feedwater increase and decrease, loss of coolant flow, and control rod withdrawal accidents in order to elucidate the thermal-hydraulic responses following such accidents and finally to verify the system design of the SMARTP. Full functional control logics have been implemented in the VISTA facility in order to control the required control action for an accident simulation. As one of the sensitivity tests to verify the PRHRS performance, the effects of the initial water level in the compensation tank are experimentally investigated. When the initial water level is 16%, the water is quickly drained and nitrogen gas is then introduced into the PRHR system, resulting in deterioration of the PRHRS performance. It is thus found that nitrogen ingression should be prevented to ensure stable PRHRS operation.

• Journal of the Earthquake Engineering Society of Korea
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• v.18 no.3
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• pp.141-150
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• 2014

A methodology to evaluate the seismic performance of interface piping systems that cross the isolation interface in the seismically isolated nuclear power plant (NPP) was developed. The developed methodology was applied to the safety-related interface piping system to demonstrate the seismic performance of the target piping system. Not only the seismic performance for the design level earthquakes but also the performance for the beyond design level earthquakes were evaluated. Two artificial seismic ground input motions which were matched to the design response spectra and two historical earthquake ground motions were used for the seismic analysis of piping system. The preliminary performance evaluation results show that the excessive relative displacements can occur in the seismically isolated piping system. If the input ground motion contained relatively high energy in the low frequency region, we could find that the stress response of the piping system exceed the allowable stress level even though the intensity of the input ground motion is equal to the design level earthquake. The structural responses and seismic performances of piping system were varied sensitively with respect to the intensities and frequency contents of input ground motions. Therefore, for the application of isolation system to NPPs and the verification of the safety of piping system, the seismic performance of the piping system subjected to the earthquake at the target NPP site should be evaluated firstly.

• Journal of Aerospace System Engineering
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• v.11 no.6
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• pp.42-49
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• 2017

A 10kw wind turbine blade aerodynamic design was carried out using the self-developed program AeroDA. The concept, basic shape, and optimization were designed and verified. A performance analysis was carried out and the key factors in each design stage are summarized. In addition, a guide for the placement of cross-section airfoils constituting the blades is presented, and the importance of the stall margin test as a method of verifying aerodynamic design is summarized. In order to verify the design program AeroDA, we compared the results of the performance analysis with a specialized program DNVGL_Bladed.

• Journal of Radiation Protection and Research
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• v.41 no.4
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• pp.384-388
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• 2016

Background: For a verification of newly-developed neutron absorbers, one of guidelines on the qualification and acceptance of neutron absorbers is the neutron attenuation test. However, this approach can cause a problem for the qualifications that it cannot distinguish how the neutron attenuates from materials. Materials and Methods: In this study, an estimation method of neutron absorption performances for materials is proposed to detect both direct penetration and back-scattering neutrons. For the verification of the proposed method, MCNP simulations with the experimental system designed in this study were pursued using the polyethylene, iron, normal glass and the vitrified form. Results and Discussion: The results show that it can easily test neutron absorption ability using single absorber model. Also, from simulation results of single absorber and double absorbers model, it is verified that the proposed method can evaluate not only the direct thermal neutrons passing through materials, but also the scattered neutrons reflected to the materials. Therefore, the neutron absorption performances can be accurately estimated using the proposed method comparing with the conventional neutron attenuation test. Conclusion: It is expected that the proposed method can contribute to increase the reliability of the performance of neutron absorbers.

• Journal of the Korean Solar Energy Society
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• v.29 no.1
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• pp.24-31
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• 2009

The aim of this study is to develop a software tool of thermal performance and economic analysis of windows, called WEPTools which helps architects, builders, and engineers quickly identify the most cost-effective window system in the very early stages of the design process. This software is suitable for examining middle or Large-sized commercial and residential buildings that are characterized by one thermal zone. To establish the reliability of the simulation results, we adopt TRNSYS algorithm of which verification has already well approved. Therefore it performs whole-building energy analysis for 8760 hours/year, including dynamic thermal calculation.

• IEMEK Journal of Embedded Systems and Applications
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• v.8 no.1
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• pp.17-24
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• 2013

In this paper, we present a multi-core processor including multimedia specific instructions to process multimedia data efficiently in the mobile environment. Multimedia specific instructions exploit subword level parallelism (SLP), while the multi-core processor exploits data level parallelism (DLP). These combined parallelisms improve the performance of multimedia processing applications. The proposed multi-core processor including multimedia specific instructions is implemented and tested using a Xilinx ISE 10.1 tool and SoCMaster3 testbed system including Vertex 4 FPGA. Experimental results using a fire detection algorithm show that multimedia specific instructions outperform baseline instructions in the same multi-core architecture in terms of performance (1.2x better), energy efficiency (1.37x better), and area efficiency (1.23x better).

• Proceedings of the KIEE Conference
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• 2005.07a
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• pp.834-836
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• 2005

This paper describes algorithms for enhancing the reliability of measurements to verify the performance of energy efficiency programs with an simple method. Fundamentally, measurements contain erroneous data because of the various causes. and so proper procedures or schemes are prepared before the performance is evaluated. In this paper, we propose an approach for detecting and correcting an adulterate data, such as missing and bad data. Erroneous data are detected or corrected by pre-described measuring conditions, ensemble average, and standard deviation of measurements at measuring time. The proposed algorithms are tested by field test measurements. From case studies we drew the promising results.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2020.11a
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• pp.109-110
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• 2020

In This study, we tried to review an efficient curing method in consideration of safety and constructability among the problems of winter construction. In other words, as a result of the mock-up test, the measured value of carbon monoxide was 0 ppm in the case of an electric hot air fan. Since there is no carbon monoxide, problems such as suffocation are expected to be solved. In terms of temperature characteristics, electric hot air fans exhibited high thermal efficiency performance with a slight difference in upper/lower temperatures compared to the existing ones. In the future, we plan to conduct thermal efficiency evaluation through actual site performance verification. We will propose an efficient curing method through applicability evaluation.