• Journal of the Korea Academia-Industrial cooperation Society
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• v.5 no.4
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• pp.350-353
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• 2004

The integral reactor is tripped by the boron injection to the reactor when the CEA(Control element assembly) is not available due to its malfunction. In general, the borated water is made by dissolving the boron powder in the water and is stored in a tank. and then injected. But, this method is disadvantageous from the view point of construction cost, operation and maintenance because it has many components and is complicated. In this study, the boron powder direct vessel injection method is adopted to improve the system. Injecting the boron powder directly to the vessel and decreasing of number of components, the system configuration, operation and maintenance is simplified and the construction cost is reduced.

• Proceedings of the IEEK Conference
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• 1999.11a
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• pp.935-938
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• 1999

메모리 테스트는 Built-In Self Test(BIST)와 같이 메모리에 내장된 회로를 통하여 자체 점검하는 방법과 테스터를 통하여 생성된 패턴을 주입하는 방법이 있다. 테스트 패턴 생성방법으로는 각각의 고장모델에 대한 테스트 패턴을 deterministic하게 생성해주는 방법과 Pseudo Random Pattern Generator(PRPG)를 이용하여 생성하는 경우로 구분할 수 있다. 본 연구에서는 PRPG를 패턴 생성기로 사용하여 여러 가지 메모리의 결함을 대표한다고 볼 수 있는 Static 및 Dynamic Neighborhood Pattern Sensitive Fault(NPSF) 등 다양한 종류의 고장을 점검할 수 있도록 메모리 BIST를 구성하였다. 기존의 Linear Feedback Shift Register(LFSR)보다 본 연구에서 제안하는 Linear Hybrid Cellular Automata(LHCA)를 이용한 PRPG가 높고 안정된 고장 점검도를 나타내었다.

• Aerospace Engineering and Technology
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• v.11 no.2
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• pp.129-139
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• 2012

This paper will describe the structure and characteristics of operator training system which was developed to maintain the quality of operational ability for COMS (Communication, Ocean and Meteorological Satellite) operators during a long-term nominal operations of missions and a contingency operations against an occurrence of anomaly. In particular it will present benefits and expected effects of the training system with a focus on three parts which are functions especially for trainer-friendly failure injection, an automatic sequencer of training scenario based on the predefined plan and additional functions of the existing COMS simulator. Furthermore, it will present a practical example of training on the training system to understand the overall mechanism of training process.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.05a
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• pp.767-770
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• 2009

In this paper, I studied the "Establishment of Fault Tolerant System" as well as the sensor and cylinder that are general components being used in automation equipments. I design a system that when the sensor breaks down on free flow conveyor, it will be converted to virtual sensor system mode by simulation, also I design IPC(Internal Pressure Cylinder), a basis of various applicable fault tolerant system by analyzing the changing of analog data according to the load of operation. With IPC and the increasing ability of developer, the Fault Tolerant System will be widely applied in the increasment of service time of cylinder, grease pouring time expection, fault recognition of cylinder and etc.

• The Journal of the Korea institute of electronic communication sciences
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• v.19 no.2
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• pp.361-370
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• 2024

In this paper, a method was studied for applying a series resonant type fault current limiter that can be manufactured at low cost to the smart grid distribution system. First, the impact of the harmonic components of the short-circuit fault current injected into the series resonance circuit of the fault current limiter on the peak value of the transient response was analyzed, and a methodology for determining the steady-state response was studied using percent impedance-based fault current computation method. Next, the effectiveness of the method was verified by applying it to a test distribution line. The test distribution system using the designed current limiter was modeled using EMTP_RV, and a three-phase short-circuit fault was simulated. In the fault simulation results, it was confirmed that the steady-state response of the fault current accurately followed the design target value after applying the fault current limiter. In addition, by comparing the fault current waveform before and after applying the fault current limiter, it was confirmed that the fault current was greatly suppressed, confirming the effect of applying the series resonance type current limiter to the distribution system.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.20 no.6
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• pp.299-312
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• 2021

Autonomous vehicles using V2X can drive safely information on areas outside the sensor coverage of autonomous vehicles conventional autonomous vehicles. As V2X technology has emerged as a key component of autonomous vehicles, research on V2X security is actively underway research on risk analysis due to failure of V2X communication is insufficient. In this paper, the service scenario and function of autonomous driving system V2X were derived by presenting the intersection scenario of the autonomous vehicle, the malfunction was defined by analyzing the hazard of V2X. he ISO26262 Part3 process was used to analyze the risk of malfunction of autonomous vehicle V2X. In addition, a fault injection scenario was presented to verify the fail-safe of the simulation-based intersection scenario.

• Proceedings of the KIPE Conference
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• 2011.07a
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• pp.186-187
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• 2011

3상 PWM 컨버터에서 LCL필터 필름 커패시터는 Self-healing 메커니즘에 의해 열화가 진행되며, 이는 시스템의 필터성능과 역률 저하로 이어진다. 따라서 계통측 커패시터의 고장을 판단하고 교체시기를 결정하는 것이 필요하다. 본 논문에서는 정전용량의 80%에 해당하는 공진주파수를 한 주기 동안 주입하였을 때 나타나는 응답의 변화를 통해 커패시터의 열화고장진단 알고리즘을 제안하였다.

• Proceedings of the KIEE Conference
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• 2000.07a
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• pp.40-42
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• 2000

동일한 변압기에서 인출된 서로 다른 선로 중 한 곳에서 지락이나 단락등의 사고가 발생하면, 고장선로 뿐 아니라 주변선로에도 사고가 제거되기 전까지 전압강하 현상이 발생하게 된다. 근래에 들어서 이러한 현상에 의한 피해사례가 많이 보고되고 있으며, 전력공급자나 수용가에서도 이 문제에 대해 높은 관심을 보이고 있다. 본 논문에서는 이러한 문제에 대한 대책으로 직렬변압기를 통하여 전압을 주입함으로서 부하에 항상 안정적인 전압을 공급할 수 있는 순간전압 보상장치에 대하여 연구하였다. 본 논문에서는 입력 전압의 peak값을 검출하여 직렬 주입될 전압의 크기와 위상을 구하는 방식을 사용하였고, 20kW급 prototype을 제작하여 실험을 수행하였다.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.661-662
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• 2015

최근 친환경적인 기술 개발에 대한 요구가 증가함에 따라 기존 엔진의 역할을 직접적으로 대체하게 되는 전기자동차용 전동기에 대한 연구가 활발히 진행되고 있다. 영구자석을 사용한 전동기의 경우, 계자 권선이 없기 때문에 회전자 동손이 없어지면서 효율이 높아지는 장점이 있지만 온도 상승 및 과부하 등으로 인한 영구자석의 불가역 감자로 인한 고장 가능성이 존재한다. 본 논문에서는 이러한 영구자석 감자현상을 진단하기 위한 방법 중 하나로 회전자 구속 조건에서 저전압 고주파 주입을 통한 입력전류 파형의 스펙트럼 분석을 제안한다. 제안한 방법은 전동기의 회전자를 구속시킨 상태에서 진단신호를 입력하고 인버터의 출력전류 파형을 측정하여 스펙트럼 분석을 수행하는 방법이다. 제안한 방법은 시뮬레이션을 통해 검증하였다.

• Transactions of the Korean Society of Automotive Engineers
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• v.22 no.3
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• pp.68-74
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• 2014

As the number of ECUs (Electronic control units) are increasing, reliability and functional stability of a software in an ECU is getting more important. Therefore the application of functional safety standards ISO 26262 is making the software more reliable. Software fault injection test (SFIT) is required as a verification technique for the application of ISO 26262. In case of applying SFIT, an artificial error is injected to inspect the vulnerability of the system which is not easily detected during normal operation. In this paper, the basic concept of SFIT will be examined and the application of SIFT based on ISO26262 will be described.