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유도전동기에 발생되는 고장신호 검출 해석모델에 관한 연구
김선화(Seonhwa Kim),노영진(Youngjin Roh),임강민(Gangmin Lim),김현철(Hyeonchul Kim) 대한기계학회 2019 대한기계학회 춘추학술대회 Vol.2019 No.11
This paper presents the calculation of unbalanced magnetic pull (UMP) due to the geometrical problem in induction motor and evaluation of the stability of the motor system. Usually, the excessive noise and vibration occurred in the induction motor by means of geometrical problem. The existence of abnormal assembling in the rotor will produce airgap permeance wave which is a function of axial and circumferential coordinate. In this paper, the UMP is calculated using permeance and magnetomotive force (MMF) and it is not only the case of parallel eccentricity but also static and dynamic misalignment. Based on the percentage of misalignment and eccentricity, the result shows that the UMP and magnetic pressure are increased according to the increasing of misalignment and eccentricity. The UMP is occurred not only in 2fL frequency component but also the others.
최재원(Jaewon Choi),김선화(Seonhwa Kim),임강민(Gangmin Lim),이동기(Donggi Lee) 대한기계학회 2019 대한기계학회 춘추학술대회 Vol.2019 No.11
In recent years, as the power demand of thermal power plants increases, the amount of fuel used increases, resulting in an increase in coal supply, which increases the operational burden on major components of the fuel system and increases the frequency of failures. Vibration analysis is one of the representative methods of nondestructive testing used to diagnose the failure of rotating machinery. This study is a case study related to conveyor system equipment diagnosis of thermal power plant. Especially, it is a case of diagnosing failure of gearbox, bearing, etc. of rotating equipment based on ISO standard. The vibration of the Conveyor Drive Motor was measured using ISO 20816. The review confirmed that the application of Class IV was necessary due to the flexible foundation structure. In addition, it was confirmed that the rotational speed component (29.9 Hz) was dominant in the case of the motor, and the rotational speed component (29.9 Hz) was also dominant in the reducer. Vibration caused by the gear defect frequency component has less energy transfer effect and the looseness phenomenon was observed. As a recommendation, it was found that the field balancing needs to be carried out on the motor side, and the stiffness reinforcement is necessary to remove the effect of looseness.
박동희(Donghee Park),안병현(Byunghyun Ahn),김효중(Hyojung Kim),하정민(Jeongmin Ha),임강민(Gangmin Lim),최병근(Byeongkeun Choi) 한국소음진동공학회 2017 한국소음진동공학회 논문집 Vol.27 No.5
Ultrasound signal is widely used to detect fault by heterodyned signal. Typically an expert will scan around the object with the scanning module while listening through headphones and observing a display panel. But this diagnosis procedure is required by specialized expert and hardly detect early defect. In this paper, Feature selection based on GA (genetic algorithms) is selected from the features of ultrasound signal on frequency domain and time domain. Then, by using the Support Vector Machine one of the machine learning, the performance of classification is evaluated by extracted features and selected features. The results of classification is compared with feature extraction based on PCA (principal component analysis). Therefore, the feature selected for each defect can be used as a reference by feature analysis for ultrasound.