• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2004년도 학술대회 논문집 정보 및 제어부문
• /
• pp.711-713
• /
• 2004

In the past time, the protection relay did only a protection function. Currently, its upgraded device i.e. IED(Intelligent Electric Device) has been designed to protect, control, and monitor the whole power system automatically. Also the device is desired to successfully measure important elements of the power system. This paper considers design method of a digital protection IED with a function of measuring various elements and a communication function. The protection IED is composed of the specific function modules that are signal process module, communication module, input/output module and main control module. A signal process module use a DSP processor for analysis of input signal. Main control module use a embedded processor, Xscale, that has an ARM Core. The communication protocol uses IEC61850 protocol that becomes standard in the future. The protection IED is able to process mass information with high-performance processor. As each function module is designed individually, the reliability of the device can be enhanced.

• 대한전기학회논문지:전력기술부문A
• /
• 제50권9호
• /
• pp.411-416
• /
• 2001

Distance relay is the most widely used in transmission line protection because it is applicable not only as main protection but also as back-up protection. However, the protection range of the distance relay is always fixed in the unchangeable operating range while the power system varies, and therefore the distance relay is the device that is the highly influenced by the power system changes. In this regard, this paper describes an approach to minimize the mal-operation of the distance relay due to the power system changes through changing protection range of the distance relay into optimal condition in response to the load variation and power system condition. Also mal-function of the distance repay in case of high resistance ground faults could be minimized through modeling the protection range into quadratic function.

• 조명전기설비학회논문지
• /
• 제27권12호
• /
• pp.74-80
• /
• 2013

Generator faults does not happen more often than the transmission and substation facility faults. However, impacts on the power system by generator faults are very large. In order to minimize the impact of generator faults, generator protection and control system with high reliability is required. Most of the generator relay in generator protection and control system of large power plant of Korea is operated by imports from abroad. Accordingly, in order to accumulate source technology and increase the import substitution effect, localization of multi-function generator protection IED is being developed. This paper deals with the implementation of a multi-function prototype IED H/W, which can be command and data exchange through communication for measuring, monitoring, protection and control. And the IED specification, various relay elements, measurement elements, communication functions, module function, and test system for the prototype IED H/W are described.

• 전기학회논문지
• /
• 제67권11호
• /
• pp.1570-1575
• /
• 2018

The increased penetration of PV is impacting on grid operation and in particular the voltage within the local grid can be significantly influenced by the various PV systems. The increased penetration of PV is impacting on grid operation and in particular the voltage within the local grid can be significantly influenced by the various PV systems. This paper describes domestic technical standard of Photovoltaic(PV) PCS(Power Conditioning Systems)- Characteristics of the utility interface. Especially protective function test items of 1) Output overvoltage protection test, 2) Output undervoltage protection test, 3) Frequency rise protection test, 4) Frequency fall protection test, 5) System voltage's momentary interruptions, 6) System voltage distortion capability test. Therefore in this paper protective function test item of facilities evaluation detailed standards for new renewable energy, small, medium and large photovoltaic inverter standard is studied and analyzed and finally full tested by PV inverter performance function.

• 디지털콘텐츠학회 논문지
• /
• 제18권4호
• /
• pp.795-802
• /
• 2017

자연재난 및 사회재난 등으로 인해 국가기반시설의 기능이 정지되어 국가기반체계가 마비된다면 국민의 생명 신체 및 재산피해는 물론 국가안보에 심각한 위협요인으로 작용할 수 있다. 본 논문에서는 국가기반체계 보호제도에 대한 국내외 동향을 살펴보고 국가운영연속성인 핵심기능연속성의 세부구성 요소인 필수기능, 승계 순서, 권한의 위임, 연속성 시설, 연속성 통신, 중요 기록 관리, 인적 자본, 테스트, 교육 및 훈련, 통제 및 지시 권한이양, 복원에 대하여 구체적으로 알아보고 국가기반 체계 보호계획 관련제도의 분석을 실시하여 구체적인 문제를 살펴보고 효율적인 국가기반체계 보호제도 개선안을 제시하였다.

• 한국생활과학회지
• /
• 제22권1호
• /
• pp.141-155
• /
• 2013

The purpose of this study is to identify consumers' needs and purchase intention of high-functional sportswear according to sports participation motivations. Internet survey was done for data collection and the subjects were 300 consumers in their 20-39's who participated in sport activities at least once a week. Factors of sport participation motivations were ostentation, social interaction, self development, mental health, and physical health. Consumers were segmented into the motivation retard group, the multi-purpose pursuit group, the health pursuit group, and the extrinsic motivation pursuit group. And factors of consumers' needs for high-functional sportswear were practicality and comfort function, body protection and physical function, and skin protection and health function. The multi-purpose pursuit group showed strong needs for active and comfort, body protection and physical function, and skin protection and health function but the motivation retard group showed the lowest needs for high functional sportswear. Purchase experiences of high-functional sportswear, accomplishment, and duration period of sport activity affected positively on the purchase intention of high-functional sportswear.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2000년도 춘계학술대회 논문집
• /
• pp.202-209
• /
• 2000

This paper introduces the main function and protection method of IGBT gate driver that designed by KOROS. Recently, the applications of insulated gate bipolar transistors(IGBTs) have expanded widely, particularly in the area of railway converters. This driver is suitable for railway traction applications, so they are designed for circumstance of railway vehicle such as vibration. The input control power for this driver is supplied from battery charger of railway. it is no necessary an isolated power supply board or auxiliary power supply, with substantial savings in cost and space in railway applications. This gate driver can be used wide range of input voltage. So, performance of the driver has no relation with the battery voltage(70V∼110V). The protection methods of IGBT gate driver have many kind of ways, but this gate driver it designed to apply to converter for railway system, so this gate driver includes protection for arm short current and low control power voltage, etc. And the process of protection method and protection reference value are optimized by means of sufficient test with our own facilities.

• Journal of the Korean Statistical Society
• /
• 제31권3호
• /
• pp.379-389
• /
• 2002

For two normal distribution with unknown means and unknown variances, a sequential procedure for estimating the difference of two normal means which satisfies both the coverage probability condition and the $\beta$-protection is proposed under some smoothness of variable imprecision function, and the asymptotic normality of the proposed stopping time after some centering and scaling is given.

• 대한전기학회논문지:전력기술부문A
• /
• 제50권8호
• /
• pp.365-372
• /
• 2001

This paper presents a new protection concept to achieve the adaptive optimal function by introducing the multi-agent system technology. Making each relay an agent which consists of relay agent module and coordinator module, each agent works autonomously to improve protection capability by cooperating with other agents. It is applied to the overcurrent protection system of the industrial power system in order to show the feasibility of the proposed methodology.

• International journal of advanced smart convergence
• /
• 제13권3호
• /
• pp.376-387
• /
• 2024

This paper examines the performance improvement of a photovoltaic power generation system with a surge protection function by applying a digital surge detection device for surge suppression in a direct current distribution panel applied to a photovoltaic power generation system. The main components used for surge protection are mainly SAD, MOV, and GTA components, and a digital surge detection device was additionally applied to this. Each component has advantages and disadvantages in terms of performance and functionality for surge protection, so a surge protection device with meaningful performance and functionality must be designed in a complex device structure that harmonizes the advantages and disadvantages of each component in order to construct a surge protection device with meaningful performance and function. Through empirical experiments, a performance analysis of a complex surge detection device to which a digital surge detection device is applied was conducted. As a result of the experiment, through absorption and blocking of surges detected through a digital surge detection device, it has both absorption and blocking performance for surges and exhibits surge absorption characteristics for hundreds of voltages in micro second. This performance showed a relatively stable state against surge noise compared to conventional devices, which produced an output waveform of stable quality in the inverter output waveform.