• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• 제5B권2호
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• pp.103-110
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• 2005

Broken rotor bars in induction motors can be detected by monitoring any abnormality of the spectrum amplitudes at certain frequencies in the motor current spectrum. Broken rotor bar fault detection schemes should rely on multiple signatures in order to overcome or reduce the effect of any misinterpretation of the signatures that are obscured by factors such as measurement noises and different load conditions. Multiple Discriminant Analysis (MDA) and Artificial Neural Networks (ANN) provide appropriate environments to develop such fault detection schemes because of their multi-input processing capabilities. This paper describes two fault detection schemes for broken rotor bar fault detection with multiple signature processing, and demonstrates that multiple signature processing is more efficient than single signature processing.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 D
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• pp.2535-2537
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• 2000

In order to detect and monitor the broken cords of steel-cord belt from being damaged by impact of large lump of materials and the corrosion of steel cord, we developed a non-contact magnetic coil detection system. This measures the deterioration of reinforcing cables in steel cord conveyor belt which transport the ores in raw material plant. In this research, magnetic coil sensor of broken-cord detection system has exciting part and sensing part. The broken-cord detection system is operated by supplying a transmitter coil with electric power to generate magnetic field, and then the change of induced voltage is detected in each receiver coils due to resultant magnetic flux effected by the broken steel cords at the inside of the conveyor belt. By the informations such as the position and size of the broken steel cords obtained by SCBMS(Steel Cord Belt Monitoring System), it is expected that not only the span of belt life will be lengthened, but also this system can enable operators to plan scheduled maintenance and prevent the enlargement of damaged parts in steel cord belt at an early stage

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2006년도 하계종합학술대회
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• pp.847-848
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• 2006

R-type thermocouple(TC) interface circuits with cold-junction compensator(CJC) and its broken wires detection was developed. The circuit consists of a CJC device, a instrumentation amplifier(IA), and two resistor and a diode for broken wire detection. The experiment results show that the interface circuit has a good CJC function on the temperature range for $20^{\circ}C$ to $1400^{\circ}C$. At the range the output voltage of the IA was -14V when the TC was broken. At normal operation condition the output voltage of IA was 0V to 10V for the temperature range.

• 한국멀티미디어학회논문지
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• 제15권3호
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• pp.312-322
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• 2012

The paper presents an approach for recognizing the broken area of the traffic signs. The method is based on the Recognition System for Traffic Signs (RSTS). This paper describes an approach to using the location histogram matching for the broken traffic signs recognition, after the general process of the image detection and image categorization. The recognition proceeds by using the SIFT matching to adjust the acquired image to a standard position, then the histogram bin will be compared preprocessed image with reference image, and finally output the location and percents value of the broken area. And between the processing, some preprocessing like the blurring is added in the paper to improve the performance. And after the reorganization, the program can operate with the GPS for traffic signs maintenance. Experimental results verified that our scheme have a relatively high recognition rate and a good performance in general situation.

• 한국철도학회논문집
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• 제20권2호
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• pp.190-195
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• 2017

본 논문에서는 임피던스 측정을 통한 레일절손을 검지하는 방법에 대해서 제시하도록 한다. 일반적으로 레일절손은 궤도회로를 통해 실시간으로 판단을 하나 궤도회로를 사용하지 않고 레일의 임피던스를 측정함으로 인해서 절손유무와 절손위치를 추정하였다. 레일의 한쪽에 병렬공진을 발생시켜 전기적으로 절연을 함으로써 다른쪽 레일의 임피던스가 측정되도록하였다. 측정된 임피던스가 인덕턴스 성분을 가지면 레일의 절손이 존재하지 않으며, 캐패시턴스 성분을 가지면 레일의 절손이 발생하게된다. 전송선로모델을 이용하여 제시한 구조를 모델링하였으며, 모델링을 통해 임피던스 값에 따라 절손위치가 추정가능함을 보였다. 실제 60m 레일 모형에 대해서 제안한 방법으로 임피던스를 측정하였으며, 임피던스 값에 따라 절손유무가 판단이 되는 것을 확인하였다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.2082-2089
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• 2011

This study is examination of application on site for performance and stability of real-time broken rail detection equipment development system about connection, welded part occurring data errors of broken rail monitoring system. As a result of analysis about data collected in Seoul Metro No.2 Subway from Mar. 2010 to Jan. 2011, we found it is possible to detect crack location(Thermit welding) within the margin of error of ${\pm}1m$ accurately as the first attenuation was -1.2dB and the second was -1.3dB.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2001년도 Proceedings ICPE 01 2001 International Conference on Power Electronics
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• pp.365-368
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• 2001

The advantage of the squirrel cage induction motor is the brush less rotor. This advantage for operation and maintenance turns out to be a disadvantage for the detection of the cage rotor bar and endring defects, which means that the detection of cage faults is due to the measurement and analysis of only the stator input signals. The monitoring task in an inverter drive is complicated mainly because the voltage and current waveforms are nonsinusoidal and the high dv/dt values from fast switching inverterd distort the measurements. In this paper, we are going to discuss the detection method of broken rotor bar of the inverter fed squirrel cage induction motor by the motor current signature analysis(MCSA) and the opening terminal voltage signal analysis.

• 한국소음진동공학회논문집
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• 제12권4호
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• pp.287-293
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• 2002

The unexpected failure of the induction motor makes the downtime of production, and the cost of the process cessation enormous. To reduce the downtime and increase the reliability of the motor, the vibration measurements for the fault detection have been used previously. Recently motor current signature analysis(MCSA) has been adapted for the fault detection and diagnosis of the motors. MCSA provides a powerful analysis tool for detecting the presence of mechanical and electrical faults in both the motor and driven equipment. In this paper, the fault severity of the rotor bar has been derived in terms of the resistance change which is calculated from the equivalent circuit model. Results show that the fault of the rotor can be easily detected and the measured value of the resistance change is verified by the detected fault from on-site tests using MCSA for the induction motors in an iron foundry.

• Journal of Power Electronics
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• 제6권3호
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• pp.245-252
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• 2006

This paper presents a method based on neural networks to detect the broken rotor bars and end rings of squirrel cage induction motors. At first, detection methods are studied, and then traditional methods of fault detection and dynamic models of induction motors by using winding function model are introduced. In this method, all of the stator slots and rotor bars are considered, thus the performance of the motor in healthy situations or breakage in each part can be checked. The frequency spectrum of current signals is derived by using Fourier transformation and is analyzed in different conditions. In continuation, an analytical discussion and a simple algorithm are presented to detect the fault. This algorithm is based on neural networks. The neural network has been trained by using information of a 1.1 KW induction motor. This system has been tested with a different amount of load torque, and it is capable of working on-line and of recognizing all normal and ill conditions.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.1041-1042
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• 2007

This paper proposes a new method for detecting broken rotor bars in a squirrel-cage induction motor. The air-gap flux variation analysis was done using search coils inserted in stator slots when broken rotor bar occurs. An accurate modeling and analysis of air-gap flux variation in the induction motor are developed using finite-element (FE) software packages, and measurement of the flux are made using search coils. The simulation was done for the induction motor with 380 [V], 7.5 [kW], 4 Poles, 1,760 [rpm] ratings using the commercial FE analysis tool. The simulation and experiment results can be useful for detecting the broken rotor bar of an induction motor.