• Journal of Power Electronics
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• 제18권1호
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• pp.56-69
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• 2018

In this paper, an improved Space Vector Modulation (SVM) based fault tolerant operation on a nine-level Cascaded H-Bridge (CHB) inverter with an additional backup circuit is proposed. Any type of fault in a power converter may result in a power interruption and productivity loss. Three different faults on H-bridge modules in all three phases based on the SVM approach are investigated with diagrams. Any fault in an inverter phase creates an unbalanced output voltage, which can lead to instability in the system. An additional auxiliary unit is connected in series to the three phase cascaded H-bridge circuit. With the help of this and the redundant switching states in SVM, the CHB inverter produces a balanced output with low harmonic distortion. This ensures high DC bus utilization under numerous fault conditions in three phases, which improves the system reliability. Simulation results are presented on three phase nine-level inverter with the automatic fault detection algorithm in the MATLAB/SIMULINK software tool, and experimental results are presented with DSP on five-level inverter to validate the practicality of the proposed SVM fault tolerance strategy on a CHB inverter with an auxiliary circuit.

• 한국산업융합학회 논문집
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• 제25권6_2호
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• pp.1003-1008
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• 2022

This paper proposes a method related to fault tolerance operation and characteristic analysis of asymmetric 6-phase permanent magnet synchronous motor. In general, motor drive systems with multi-phase structures can be continuously operated despite a reduction of power and speed by using a phase changeover or control techniques according to the failures. As a result, it is widely used in industrial fields such as aviation and defense, which require high efficiency and high reliability. In this paper, the second order ripple of the electrical fundamental freuqnecy occurs in the dq-axis currents of the synchronous coordinate system through mathematical analysis according to the switch open of the dual 3-phase inverter. Therefore, the fault tolerant operation method is presented by applying the fault detection method with a constant cycle for continuous operations. The effectiveness of the proposed fault tolerance operation method is verified through the several experiments.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 B
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• pp.1214-1219
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• 2002

Railway signalling system always is required high safety and reliability. The failure of the train control system can provoke a serious accident. In this paper, we show how to achieve the safety and reliability by dividing signalling system into vital and non functions, studying operational environment.

• 정보와 통신
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• 제26권3호
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• pp.69-75
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• 2009

최근 대부분의 첨단 (Mission Critical) 무기체계가 컴퓨터 노드 연결에 의한 Ethernet 네트워크 기반으로 구성되고 있어, 이에 따른 시스템의 신뢰성 측면이 더욱 중요한 요소로 대두되고 있다. 본고에서는 첨단 무기체계의 신뢰도를 높이기 위한 Fault Tolerant Ethernet (FTE)의 기본인 이중화 방식을 비교 소개하고자 한다. 기존의 소프트웨어 접근방식과 하드웨어 접근방식은 물론, 최근 본 연구팀이 제안한 복합 (Hybrid) 방식도 비교 대상으로 하였다. 또한 FTE 구현 시 필수적 고려사항인 고장감시/자동 복구 Metric 및 관련 Simulation 결과도 함께 제시한다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1987년도 전기.전자공학 학술대회 논문집(II)
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• pp.1185-1187
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• 1987

Digital systems are increasingly being used in the ranges of many control engineering. The residue number system offers the possibility of high speed operation and error correction. The compact self-checking pulse-train residue arithmetic circuit is proposed. A fault tolerant digital filter is practically implemented using these proposed circuits.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1999년도 추계종합학술대회 논문집
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• pp.707-711
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• 1999

In this paper, an algorithm of fault tolerant gaits for a quadruped robot is proposed for the purpose of tolerating a locked joint failure. The robot can continue its walking after a locked failure occurs to a joint of a leg by the proposed algorithm. In particular, a periodic gait is proposed as a special form of the proposed algorithm and its existence and efficiency are analytically proven.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1987년도 한국자동제어학술회의논문집; 한국과학기술대학, 충남; 16-17 Oct. 1987
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• pp.161-163
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• 1987

An FTCS is developed for the purpose of improving the reliability of a process control system. The proposed FTCS has capabilities of failure detection, back-up control, graphic display, and self-checking. Also the FTCS is combined with the process simulator to experiment in laboratory for the evaluation of performance of operation. The FTCS is applied to Thermal Power Plant .

• 한국통신학회논문지
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• 제21권2호
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• pp.447-460
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• 1996

Network optimization and design procedures often separate quality of service (QOS) performance measures from reliability issues. This paper considers channel allocation and flow assignment (routing) in a network subject to link failures. Fault-tolerant channel allocation and flow assingments are determined which minimize network cost while maintaining QOS performance requirements. this approach is shown to yield significant network cost reductions compared to previous heuristic methods used in the design of packet switched network with unreliable links.

• 한국통신학회논문지
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• 제23권8호
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• pp.1977-1983
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• 1998

본 논문에서는 인코더 벡터(encoder vector)에 입각하여 양, 음 체크썸 벡터(positive, negative checksum vector)를 정의하고, 이를 벡터 컨버루션(vector convolution)에 적용하여 알고리즘 기반 결함허용 벡터 컨버루션 방식을 제안하였다. 또한 제안된 방식을 배열구조에서 구현하고 복잡도 해석을 통하여 추가 리던던시(redundancy)의 규모를 검토하였다.

• Journal of Electrical Engineering and Technology
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• 제11권5호
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• pp.1423-1432
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• 2016