• Journal of Hydrogen and New Energy
• /
• v.23 no.6
• /
• pp.612-618
• /
• 2012

In this paper, in order to prevent electric shock of high voltage system of HFCV after crash test, insulation performance measurement methods were studied. Under conditions of in-use, insulation performance tests can be divided into measurement method using the vehicle's own RESS as DC voltage source and measurement method using DC voltage from off-vehicle sources. However, these tests can not be applied after a post-crash because parts of high voltage system cover should be removed, and insulation performance can be influenced during these tests. Therefore, we proposed post-crash insulation performance test methods for preventing electric shock through problem analysis of previous post-crash insulation performance tests. Also, test equipment which can measure voltage absence and total energy was developed. We verified performance of the equipment through experiments with vehicle test.

• Journal of Hydrogen and New Energy
• /
• v.22 no.6
• /
• pp.810-818
• /
• 2011

This paper analyzed the suitability about the isolation performance criteria which was based on human impedance and effect of current in IEC 60479-1 on the safety of human being was examined. The method of evaluation by megger and DC voltmeter was analyzed. The differences of isolation performance according to design of high-voltage system were analyzed. The factors which affect the insulation performance were analyzed for HFCV, EV, HEV, etc. through analysis of the isolation performance evaluation method. Finally, design for improved isolation performance was proposed.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.60 no.5
• /
• pp.1068-1072
• /
• 2011

Hydrogen Fuel Cell Vehicle(HFCV) is system that uses electrical energy of fuel cell stack to main power source, which is different system with other vehicles that use high-voltage, large-current. Isolation performance of this system which is connected with electrical fire and electrical shock is important point. Isolation resistance of electric installation is divided according to working voltage, it follows criterion more than $100{\Omega}$/VDC (or $500{\Omega}$/VAC) about system operation voltage in a hydrogen fuel cell vehicle. Although measurement of isolation resistance in a hydrogen fuel cell vehicle is two methods, it uses mainly measurement by megger. However, the present isolation resistance measurement system that is optimized to use in electrical facilities is unsuitable for isolation performance estimation of a hydrogen fuel cell vehicle because of limit of maximum short current and difference of measurement resolution. Therefore, this research developed the isolation resistance measurement system so that may be suitable in isolation performance estimation of a hydrogen fuel cell vehicle, verified isolation performance about known resistance by performance verification of laboratory level about developed system, and executed performance verification through comparing results of developed system by performance verification of vehicle level with ones of existing megger. Developed system is judged to aid estimation and upgrade of isolation performance in a hydrogen fuel cell vehicle hereafter.

• Journal of Korean Society for Quality Management
• /
• v.43 no.3
• /
• pp.299-312
• /
• 2015

Purpose: This paper analyzes the phenomenon on the degradation of the electrical performance by the pressure in the manufacturing process of sandwich type radomes. Methods: This paper consists of two steps to analyze the relation between the electrical performance and the pressure. First, the thickness of the core of the flat panels which were fabricated with different pressure was measured with the microscope, and then the electrical performance of the flat panels was analyzed with simulation and experiment. Based on the results of the electrical performance and the measured thickness with respect to the flat panels, the relation between the electrical performance and the applied pressure in the manufacturing process was analyzed. Results: The simulated and measured results with respect to the flat panel shows that the high pressure results in the nonuniform thickness of the core, which is applied to the radome fabrication. As a result, the degradation of the electrical performance occurs because the unintended scattered field is generated as the electromagnetic wave transmits (or impinges upon) the radome. Furthermore, we observed that the electrical performance of both the flat panel and the radome got worse as the high pressure was applied. Conclusion: Through simulation and experiment, therefore, it is demonstrated that for the high pressure in the manufacturing process the nonuniform thickness of the core increases and results in the degradation of the electrical performance of the radome.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.28 no.6
• /
• pp.21-29
• /
• 2014

In this paper examine the characteristics of the generator supplying the most significant electrical energy in some parts required to drive the vehicle, and it is focused on to fabricate a performance evaluation unit for developing alternator with better performance. Through performance tests in accordance with the electrical load of alternators that is made in Valeo Corp. and Denso Corp., which are currently applied by H Corp., the fabricated performance evaluation unit has measured the power generation amount of the electrical energy supplied from the alternator, and it was analyzed. On the basis of this result, and to understand the flow of electrical energy of the vehicle, furthermore, it is intended to verify the usefulness of the performance evaluation unit which is designed in this paper. In this paper, based on the mechanism of the proposed performance evaluation unit, it will try to learn the convergence technology that can be applied to the design of the performance evaluation unit of other components of the vehicle.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2007.11a
• /
• pp.209-212
• /
• 2007

It is increased electrical energy consumption with the development of intelligence society in buildings and thus an energy conservation through efficient use of electricity and reliability, safety, etc became more important. This research paper intensively investigated performance based construction specifications and design criteria of electrical installations in domestic and foreign country. It is necessary to analyze the key features based on performance and general trend about contractor guarantee, warranty method, performance design criteria from the investigated data. This paper shows a reasonable performance based construction specifications and design criteria of electrical installations.

• JSTS:Journal of Semiconductor Technology and Science
• /
• v.1 no.2
• /
• pp.116-124
• /
• 2001

We implemented POPeye (Probe of Performance ＋ eye), a system analysis simulator to evaluate DRAM performance in a personal computer environment. When running any real-life application programs such as Microsoft Office and Paint Shop Pro on Windows OS, POPeye simulates detailed transactions between a CPU and a memory system. Using this tool, we comparatively analyzed the performance of a DDR-SDRAM, a D-RDRAM, and a DDR-FCRAM.

• Transactions of Materials Processing
• /
• v.32 no.3
• /
• pp.153-159
• /
• 2023

This paper presents the optimal design of a heating system using radiant heating elements for application in smart farms. Smart farming, an advanced agricultural technology, is based on artificial intelligence and the internet of things and promotes crop production. Temperature and humidity regulation is critical in smart farms, and thus, a heating system is essential. Radiant heating elements are devices that generate heat using electrical energy. Among other applications, radiant heating elements are used for environmental control and heating in smart farm greenhouses. The performance of these elements is directly related to their electrical energy consumption. Therefore, achieving a balance between efficient electrical energy consumption and maximum heating performance in smart farms is crucial for the optimal design of radiant heating elements. In this study, the size, electrical energy supply, heat generation efficiency, and heating performance of radiant heating elements used in these heating systems were investigated. The effects of the size and electrical energy supply of radiant heating elements on the heating performance were experimentally analyzed. As the radiant heating element size increased, the heat generation efficiency improved, but the electrical energy consumption also increased. In addition, increasing the electrical energy supply improved both the heat generation efficiency and heating performance of the radiant heating elements. Based on these results, a method for determining the optimal size and electrical energy supply of radiant heating elements was proposed, and it reduced the electrical energy consumption while maintaining an appropriate heating performance in smart farms. These research findings are expected to contribute to energy conservation and performance improvement in smart farming.

• KIEE International Transactions on Power Engineering
• /
• v.2A no.4
• /
• pp.160-165
• /
• 2002

This paper describes a proposed performance criteria and evaluation procedures for transmission system planning in Korea. Performance criteria of the transmission system are expected to be used as a guideline for investment into a transmission network. Moreover, performance evaluation procedures, which are based on current practices and widely accepted theories, are suggested to achieve fair and acceptable results.

• Proceedings of the KIEE Conference
• /
• 1995.07b
• /
• pp.658-660
• /
• 1995

This paper presents a performance analysis of the multiple sliding mode control for SISO system. The multiple sliding mode control technique uses sliding surfaces for each state. The performance analysis is done by comparison between the multiple sliding mode control and the sliding mode control. Overall performance of the multiple sliding mode control is improved over that of the sliding mode control. Results of numerical simulations are presented.