• Journal of the Korea Society of Computer and Information
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• v.16 no.3
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• pp.141-147
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• 2011

This paper proposes an efficient two-stage fault prediction algorithm for fault detection and diagnosis of induction motors. In the first phase, we use a linear predictive coding (LPC) method to extract fault patterns. In the second phase, we use a dynamic time warping (DTW) method to match fault patterns. Experiment results using eight vibration data, which were collected from an induction motor of normal fault states with sampling frequency of 8 kHz and sampling time of 2.2 second, showed that our proposed fault prediction algorithm provides about 45% better accuracy than a conventional fault diagnosis algorithm. In addition, we implemented and tested the proposed fault prediction algorithm on a testbed system including TI's TMS320F2812 DSP that we developed.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.49 no.9
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• pp.626-634
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• 2000

The paper describes a new and rigorous mathematical model using counter-EMF for the rotor field oriented system with induction motor which uses the estimated speed and rotor flux based on a Model Reference Adaptive System as well as the real-time approach. The estimated speed and rotor flux is used for the speed and flux feedback control. The stability and the convergence of the estimator are improved on the basis of hyperstability theory for non-linear systems. The validity of the proposed method is verified by simulation and also the sensorless control was tested on the propulsion system simulator used for the development of Korean High-Speed Railway Train(KHSRT).

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.1136-1139
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• 2000

The paper describes a new and rigorous mathematical model for the rotor field oriented system with induction motor which uses the estimated speed and rotor flux based on a Model Reference Adaptive System, as well as the real-time approach. The estimated speed and rotor flux is used for the speed and flux feedback control. The stability and the convergence of the estimator are improved on the basis of hyperstability theory for non-linear systems. The real-time controller and estimator are implemented with a sampling period of $926{\mu}s$ using a dual TMS320C44 floating-point digital signal processor. The validity of the proposed method is verified by simulation, and also, the sensorless control was tested on the propulsion system simulator, used for the development of Korean High-Speed Railway Train (KHSRT) [5].

• Proceedings of the KIEE Conference
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• 2005.10b
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• pp.47-49
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• 2005

This paper presents a robust speed control method of induction motors(IM) using a Non-linear PI controller(NPI), NPI is high gain controller in region of small error, and low gain controller in region of large error. so in steady state, system will be robust against variation of load torque. The simulation and experiment results confirm the validity of proposed control scheme.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.8
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• pp.54-62
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• 2006

Voltage unbalance will be generated by the load unbalance operation such as combination operation of single & three phase load and current unbalance will be more severe by the deteriorated voltage quality. Under the these unbalance conditions, all power electronic converters used in different types of electronic systems can increase harmonic disturbances by injecting harmonic currents directly into the feeder grid of three phase 4-wire. Harmonic current may cause torque to decrease. it may also overheat or become noisy and torque oscillation in the rotor can lead to mechanical resonance and vibration. This paper presents a scheme on the characteristics of induction motor under the combination of linear & non-linear loads at the three phase 4-wire power distribution system by the unbalance and harmonic components. It was able to confirm that the number of torque pulsation decreased and torque ripple values increased by the harmonics that reduction was difficult by five harmonics filters at additional driving time of single-phase non-linear load.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.9 no.3
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• pp.73-79
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• 1995

This paper describes on the design considerations and analysis of moving primary-type linear induction motor for automatic conveyer system. For the study of the designed motor characteristics, calculated values obtained from the analysis using finite element method for various operation conditions are compared with the experimental results. Using the combined interactions of the thrust, the arigap flux density, and the reactive power at standstill as performance criteria, a proper ratio of the pole pitch to the effective airgap is presented for the design criterion.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.36 no.4
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• pp.240-251
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• 1987

In this paper, with the end effect taken into consideration, the fundamental characteristics of a linear induction motor-the eddy currents of the secondary conducting sheet (traveller), the flux density in the air gap-are analysed by means of electromagnetic field theory. Accordingly, the derived governing eqations of the chatacteristics with goodness factor, presents that it was possible not only to predict the performance characteristics, but to obtain the data that needs to optimize a design of a motor with the reduction of the end effect.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1994.10a
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• pp.360-364
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• 1994

This paper is concerned with extracting the diagnostic signature for motor-operated valves (MOV's) noninvasively. A torque estimator is developed and tested to obtain electical torque of the induction motors which are attached to the MOV's. Inverse filter is used to recover the gear meshing forces from the measured actuator housing vibration, which contain the gear rotation information. Frequency demodulation techniques are performed and an adaptive linear bandpass filter is implemented to improve signal-to-noise ratio. Finally, stand-alone valve experiments are carried out to validate the signature extraction scheme.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.1047-1048
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• 2010

• Proceedings of the KIEE Conference
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• 1983.07a
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• pp.59-60
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• 1983