• Journal of Power Electronics
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• 제11권6호
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• pp.801-810
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• 2011

An open circuit fault diagnostic method in IGBTs for the ac to dc converters used in microgrid applications is developed in this paper. An ac to dc converter is a key technology for microgrids in order to interface both distributed generation (DG) and renewable energy resources (RES). Also, highly reliable ac to dc converters are necessary to keep converters in continuous operation as long as possible during power switch fault conditions. Therefore, the proposed fault diagnostic method is developed to reduce the fault detection time and to avoid any other fault alarms because continuous operation is desired. The proposed diagnostic method is a combination of the absolute normalized dc current technique and the false alarm suppression algorithm to overcome the long fault detection time and fault alarm problems. The simulation and experimental results show that the developed fault diagnostic method can perform fault detection within about one cycle. The results illustrate that the reliability of an ac to dc converter interfaced with a microgrid can be improved by using the proposed fault diagnostic method.

• 전자공학회논문지A
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• 제33A권2호
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• pp.173-183
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• 1996

In this paper, a new structure that can do fault detection and location of digial logic circuits more efficiently using current testing techniques is proposed. In the conventional method, observation point for steady state power supply current was only one, but in the proposed method more fault classes are divided for fault detection and location through the ovservation of steady state power supply current at two points. Also, it is shown that this structure can be easily applied in detection of stuck-open fault which is not easy to do testing with conventional current testing techniques. In the presented mehtod, an extra trasnistor is used, and current path is made compulsorily in the CMOS circuits in which no current path can be established in steady state, then it can be known that stuck-open tault is in the MOS transistor on the considering current path, if this path disappears due to stuck-open fault. The validity and the effectiveness is shwon, thorugh the SPICE simulation of circuits with fault and the current path search experiment using current path search program based on transistor short model wirtten in C language on SUN sparc workstation.

• 한국전자통신학회논문지
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• 제3권1호
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• pp.1-7
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• 2008

해저광케이블은 국제통신의 98% 이상을 처리하고 있는 국가의 중요한 정보통신 인프라이다. 하지만 선박의 닻, 어선의 어구, 해저 지진 등 다양한 요인으로 인해 고장이 발생하며, 고장 발생시 대용량 해저통신 트래픽의 영향을 최소화하고, 케이블 수리 선박의 운영비용 절감을 위해서 수리 기간을 최대한 단축해야 한다. 해저광케이블 고장 유형은 Shunt Fault, Cable Cut, Open Fault, Fiber Break 등 여러 유형이 있으며, 고장이 발생하면 육상 터미널 국사(육양국)에서 정확하고 신속하게 고장 유형 및 고장 지점을 파악하고, 케이블 수리 선박은 수리 현장으로 출동하여 수리 작업을 수행하게 된다. 수리작업 기간 중 육양국에서는 케이블 수리 선박에서 요청하는 각종 Test를 수행하게 되며, 이때 육양국 Test 기법은 매우 중요하다. 본 논문에서는 해저광케이블 고장 유형 및 고장 지점 탐지 기법을 제시하고, 해저광케이블 수리기간 단축을 위한 육양국 Test 기법을 고찰하고자 한다.

• 조명전기설비학회논문지
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• 제26권11호
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• pp.109-115
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• 2012

Recently, permanent magnet synchronous motor are applied to various applications. Because of the importance of high reliable operation in these areas, many research related to the fault detection and diagnosis of inverter system are conducted. So, a faults model for an inverter-driven permanent magnet synchronous motor is studied by using the fault current of motor according to switch open, which can be effectively used for performance evaluation of the diagnostic algorithm. And fault of the permanent magnet synchronous motor inverter drive system is divided into four types. The feasibility of the proposed method are improved by simulation and experiment.

• 제어로봇시스템학회논문지
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• 제16권8호
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• pp.780-785
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• 2010

The OPRoS (Open Platform for Robotic Services) framework is proposed as an application runtime environment for service robot systems. For the successful deployment of the OPRoS framework, fault tolerance support is crucial on top of its basic functionalities of lifecycle, thread and connection management. In the previous work [1] on OPRoS fault tolerance supports, we presented a framework-based fault tolerance architecture. In this paper, we extend the architecture with component-based fault tolerance techniques, which can provide more simplicity and efficiency than the pure framework-based approach. This argument is especially true for fault detection, since most faults and failure can be defined when the system cannot meet the requirement of the application functions. Specifically, the paper applies two widely-used fault detection techniques to the OPRoS framework: 'bridge component' and 'process model' component techniques for fault detection. The application details and performance of the proposed techniques are demonstrated by the same application scenario in [1]. The combination of component-based techniques with the framework-based architecture would improve the reliability of robot systems using the OPRoS framework.

• Journal of Power Electronics
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• 제11권6호
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• pp.824-836
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• 2011

A new fault-tolerant control topology for open-loop motor-drive systems with Delta-connected stator windings is introduced in this paper. This new control topology enables the operation of a three-phase induction machine as a two-phase machine fed by a three-phase inverter upon a failure in one of the motor phases. This topology utilizes the "open-Delta" configuration to independently control the current in each of the two remaining healthy phases. This new control technique leads to the alleviation of any torque pulsations resulting from the consequences of the asymmetrical conditions associated with this class of faults.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2018년도 전력전자학술대회
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• pp.270-272
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• 2018

This paper proposes an open-phase fault control system using 3-phase neutral voltage. The proposed control system is designed as a new topology which uses the potential difference between neutral point and ground(G) of three phase. And the open-phase detection system is configured to three resistance devices(Y-wiring) of the same capacity to each line of three phase power source R,S,T. This paper also designs a mobile phone application for remote alarm of open-phase fault.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2019년도 전력전자학술대회
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• pp.540-542
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• 2019

This paper proposes an open-phase fault control system using 3-phase neutral voltage. The proposed control system is designed as a new topology which uses the potential difference between neutral point and ground of three phase. The open-phase detection system is also configured to Y-wiring of three capacitance devices of the same capacity to each line of three phase power source R-S-T. This paper also designs a mobile phone application for remote alarm of open-phase fault.

• 조명전기설비학회논문지
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• 제23권6호
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• pp.40-51
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• 2009

인버터 스위치의 개당 혹은 인버터와 모터 터미널의 분리로 인해 발생하는 고장을 해석하고 진단 알고리즘의 시험 평가를 위해 효과적으로 사용할 수 있는 영구자석 동기전동기 구동 인버터의 개방 고장에 의한 제어 특성해석 및 고장모델이 제시된다. 기존의 전동기의 해석과 제어에 많이 사용되는 dq 모델은 상전압 모델을 변환한 것으로 고장 상황에서는 3상평형 조건이 성립하지 않기 때문에 개방 회로의 입력 전압을 구하기가 쉽지 않아 고장 모델의 해석을 위해 직접 사용하기 어렵다. 이를 해결하기 위해 스위치 개방에 따른 전통기의 선전압 관계를 이용한 인버터의 고장 모델이 제안되고 제안된 고장모델의 타당성을 입증하기 위해 시뮬레이션이 수행된다. 전체 시스템이 DSP TMS320F28335에 의해 구현되어 동일 고장 조건에서의 비교 실험과 특성 해석이 수행된다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1993년도 정기총회 및 추계학술대회 논문집 학회본부
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• pp.154-156
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• 1993

In this paper, fault analysis using simulation method and fault diagnosis scheme are presented for induction motor drive system. Major faults such as inverter 'a' phase open fault, inverter 'a'-'b' phase short circuit fault and inverter 'a' phase ground fault are analyzed and simulated. On-line and off-line fault diagnosis systems are proposed.