• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2002.07a
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• pp.432-437
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• 2002

현재 비파괴 상태진단기술의 세계적인 연구동향은 비접촉식 시험기술, 실시간 광역기술, 고온 환경 하에서의 시험기술, 온라인 감시기술, 고감도, 고분해능, 소형화 및 무선통신기술 등을 개발하는 방향으로 연구가 활발히 진행되고 있다. 특히 고온 환경 하에서의 시험기술의 경우 철강공장 등에서 그 수요가 급증하고 있는데 반하여 국내의 경우 개발기술이 거의 전무하며 외국에서 전량 수입에 의존하고 있는 실정이다. 최근 여러 가지 다양한 복합재료와 공업용 재료들이 개발됨에 따라 이들 재료의 제작 공정이 복잡해질 뿐만 아니라 고온 및 고압의 공정조건이 요구되는 경우가 많다. 따라서 고온환경 하에서 재료의 특성을 비파괴적으로 검사할 수 있는 초음파 탐촉자가 요구된다고 하겠다. (중략)

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.1
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• pp.464-469
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• 2019

A remote monitoring panel and control system was developed to control various valves and access control chambers, including gas shutoff valves used in CBR(Chemical, Biological and Radiological) facilities. The remote monitoring panel consisted of a main panel installed in the NBC (Nuclear, Biological and Chemical) control room and auxiliary panel installed in the clean room, and the size was divided into pure control and control including CCTV. This system can be monitored and controlled remotely according to the situation where an explosion door and gas barrier door can occur during war and during normal times. This system is divided into normal mode and war mode. In particular, it periodically senses the operation status of various valves, sensors, and filters in the CBR facilities to determine if each apparatus and equipment is in normal operation, and remotely alerts situation workers when repair or replacement is necessary. Damage due to the abnormal operation of each device in the situation can be prevented. This enables control of the blower, supply and exhaust damper, emergency generator, and coolant pump according to the state of shutoff valve and positive pressure valve in the occurrence of NBC, and prevents damage caused by abrupt inflow of conventional weapons and nuclear explosions.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1628-1629
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• 2011

산업현장에서는 회전기기의 고체절연시스템(solid insulation system)의 열화정도를 평가하기 위하여 일정 진단주기에 맞춰 Off-line 상태에서 직류시험 및 교류시험을 통하여 효과적으로 절연물에 대한 상태평가를 시행하고 있다. 직류시험으로는 절연저항, 성극지수(PI) 시험 등이 있으며 교류시험으로는 교류전류시험(${\Delta}I$), 유전정접시험(${\Delta}tan{\delta}$), 부분방전(PD)시험이 있다. 여기서 부분방전은 절연체의 국부적인 열화현상을 추정할 수 있는 중요한 파라미터로, 부분방전시험(PD test)을 통하여 고정자권선(stator winding)에 대한 절연특성을 효과적으로 진단할 수 있다. 고압 전동기는 기동정지의 빈번함과 장기간 운전에 의해 열적, 전기적, 기계적 스트레스를 받게 되고, 이로 인해 과열, 진동, 절연파괴에 이르는 문제점이 발생되어 결국 시스템의 운전정지를 초래하는 심각한 사고로 이어질 수 있다. 따라서 고압 전동기의 절연상태를 주기적으로 감시하고 사고 징후를 검출하여 시스템을 안정적으로 운영하기 위한 고압 전동기 Off-line 절연진단에 대하여 기술하고 수차발전기에 대한 절연상태진단 결과를 바탕으로 절연시스템의 신뢰성 평가 방법에 대하여 고찰하고자 한다.

• Journal of the Korean Institute of Gas
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• v.2 no.3
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• pp.88-95
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• 1998

Vibration analysis of rotating machinery can give an indication of possible faults thus allowing maintenance before further damage occurs. Current predictive maintenance system installed in Pyung-tak has the ability to diagnose the mechanical problems within the LNG Pump when the vibration exceeds preset overall alarm levels. In this study, LNG pump auto-diagnosis system based upon Windows NT and DSP Board is developed. This system analysis velocity signal acquired from dual accelerometer input monitor system to diagnose pump condition. Many plots which display machine condition are shown and features of vibration are stored in every time. If the fault is found, the system diagnoses automatically using expert system and trend monitoring. Operator checks pump condition intuitively using personal computer monitor.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.9
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• pp.1281-1286
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• 2010

Power plants have many components and equipment. It is difficult for operators to know the time of failure or the equipment that fails. Plants incur heavy economic losses due to unexpected failure. The equipment in power plants is constantly monitored by various sensors and instruments. However, prevention of failure is very difficult. Therefore, engineers are developing many types of failure-alarm systems that can detect the abnormal functioning of equipment. Such failure-alarm systems inform only about the abnormal functioning of equipment and do not indicate the cause of failure or the parts that have failed. In this study, we have developed a failure-prediction system that can provide details on the cause of trouble and the maintenance method.

• Journal of Digital Contents Society
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• v.18 no.6
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• pp.1175-1182
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• 2017

Recent trend in the manufacturing industry is focused on the convergence with IoT and Big Data, by emergence of the 4th Industrial Revolution. To realize a smart factory, the proposed system based on MTConnect technology collects and integrates various status information of machines from many production facilities including heterogeneous devices. Also it can distribute the acquisited status of heterogeneous manufacturing machines to the remote devices. As a key technology of a flexible automated production line, the proposed system can provide much possibility to manage important information such as error detection and processing state management in the unmanned automation line.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.819-820
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• 2016

Electrical power distribution is consists of high voltage, low voltage and motor control center(MCC). Motor control centers involves turning the motor on and off, it is configured electronic over current relay to detect a motor overcurrent flows. Existing electronic over current relay detects electrical fault such as overcurrent, undercurrent, phase sequence, negative sequence current, current unbalance and earth fault. However, it is difficult to detect mechanical fault such as locked rotor, motor stator and rotor and bearing fault. In this paper, we propose a condition monitoring and fault diagnosis system for electrical and mechanical fault detection of rotating machinery. The proposed system is designed with signal input and control part, system interface part and data acquisition board for condition monitoring and fault diagnosis, it was possible to detect electrical fault and mechanical fault through measurement and control of insulation resistance, locked rotor, MC counter and bearing temperature.

• Journal of the Institute of Convergence Signal Processing
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• v.6 no.1
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• pp.23-26
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• 2005

This paper describes the algorithm for deciding the status of the operating machines in the power plants. It is very important to decide whether the status of the operating machines is good or not in the industry to protect the accidents of machines and improve the operation efficiency of the plants. There are two steps to analyze the status of the running machines. First, we extract the features from the input original data. Second, we classify those features into normal/abnormal condition of the machines using the wavelet transform and the input RMS vector through the K-means algorithm. In this paper we developed the algorithm to detect the fault operation using the K-means method from the sound of the operating machines.

• Journal of KSNVE
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• v.6 no.3
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• pp.341-347
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• 1996

Vibration analysis is one of the most powerful tools available for the detection and isolation of incipient faults in mechanical systems. The methods of vibration analysis in use today and under continuous study are broad band vibration monitoring, time domain analysis, and frequency domain analysis. In recent years, great interest has been generated concerning the use of time- frequency repesentation and its application for a machinery diagnostics and condition monitoring system. The objective of the study described in this paper was to develop a new diagnostic tool for the rotating machinery. This paper introduces a new time frequency representation. Directional Winger-Ville Distribution, which analyese the time-frequency structure of the rotating machinery vibration.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.674-677
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• 2000

This paper describes a remote monitoring and control system using mobile internet environments through TCP/IP. The server program acts as the main interface between the machine system and the internet technology. The client program is to be distributed to the remote users such as PDA who want to monitor the machine status. A server system is designed to send information of the faults and status of application system to the client part. Therefore, The client parts can take measures and control the system remotely according to the error and faults of system. We developed the client- serversystem for remote control of a green house environment.