• Proceedings of the KIEE Conference
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• 1993.11a
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• pp.63-65
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• 1993

In short primary, short secondary Single-sided Liner Induction Motor (SLIM), the thrust calculation is difficult when the overlapped area changes between the primary and the secondary. To solve this problem, we construct neural network that its inputs are the secondary displacement and the slip, and predict the thrust.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.91.3-91
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• 2002

This paper describes a design of an induction motor control system for industrial sewing machines. On the basis of vector control principle, the control system is simulated by using the ACSL, implemented on a DSP(TMS320C31).A space vector modulation is used as the inverter switching strategy. For the application of industrial sewing machines, A fast acceleration (deceleration) and removal of velocity ripples are required, because a sewing quality and sewing machines life time depends on these characteristics. The designed control system has fast dynamic characteristics and small speed vibration. The result is applied to the industrial sewing machine and result are shown.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.878-879
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• 2015

최근 산업계에서 널리 사용되고 있는 유도전동기, 특히 단상 유도전동기는 고주파에 의한 영향으로 인하여 crawling 현상이 발생하기도 한다. 이러한 고주파에 의한 영향을 저감시키기 위하여 주로 skew를 적용시키고 있다. 본 논문에서는 crawling 현상 저감을 위하여 skew 값에 따른 각 차수별 고주파를 분석하고 양호한 토크 특성을 발생시키도록 연구되었다. 또한 2D 해석 및 샘플 제작을 통한 실험을 통하여 실제 모델에서의 skew에 의한 crawling 현상 저감을 확인하였다.

• Proceedings of the KIEE Conference
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• 1998.07f
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• pp.2169-2171
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• 1998

In order to improved the three phase GTO CSI of high efficiency IM drive with low loss commutation and snubber energy, we studied the energy recovery circuit to recover stored energy in clamping capacitor, dc link inductor and snubber capacitor, used an induction motor as the load of inverter. Specially, we investigated how dc input power is increased or decreased according to size of dc link inductor. The validity of this system is proved through experiment.

• Proceedings of the KIEE Conference
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• 1994.07a
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• pp.174-176
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• 1994

In the moving secondary type linear induction motor(LIM), because the secondary don't get continual thrust, it is difficult to analyze the dynamic characteristics. So we have resolved this problem by using the neural network.

• Proceedings of the KIEE Conference
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• 1994.07a
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• pp.33-35
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• 1994

In Linear Induction Motor(LIM), the end effect is caused by the abrupt change in the airgap magnetic reluctance at both ends of the machina Especially, in high speed, it has an adverse effect on various characteristics of LIM such as thrust, efficiency, power factor, etc. In this paper, we analyze the end effect, and describes the method to reduce end effect essentially and decrease the secondary material cost.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.51 no.8
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• pp.361-367
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• 2002

Many failures in high voltage equipment are preceded by partial discharge activity. In this paper deals with the application of the high frequency partial discharge measurement technique in motorette. HFPD measurement is very effective method to detect the PD occurred in motorette which is the called name of test specimen for accelerating test of stator winding[1] In this study, CT type HFPD sensor is used to detect the partial discharges and a measured HFPD pattern is analyzed by fractal mathematics. The neural network algorithm is used to pattern recognition and ageing diagnosis. As a result of this study, the fractal dimensions are increased along to applied voltage and HFPD pattern recognition using neural network shown excellent recognition rate. Also, the ageing diagnosis of motorette has been Possible.

• Proceedings of the KIEE Conference
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• 1998.07a
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• pp.28-30
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• 1998

In the case of long secondary (applied in long distance), as it is established horizontal, the defects of droop arises resulting damage of entire system. Actually, it is difficult to expect reasonable characteristics and desirable operating in that case. This paper is about numerical analysis of secondary droop, non-symmetric and position displacement problems. In the base of this paper, the correction of mechanical difficulties in practical manufacturing and optimal design of TLIM considering these aspects can be progressed successively.

• Proceedings of the KIEE Conference
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• 1995.07a
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• pp.3-5
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• 1995

For a linear induction motor(LIM), the constants of each phase are different due to the structure. In this paper, a vector control analysis method of a LIM taking into consideration its asymmetrical constants are proposed. And, in order to prove the propriety of proposed vector control method and to analyze the dynamic characteristics of LIM's vector control, FEM taking into account of movement and using stator tapped winding is used in the analysis region. So, It is confirmed that the proposed asymetrical constants vector control theory and simulation method of mixing with FEM is appropriate to dynamic characteristics analysis of LIM.

• Journal of Electrical Engineering and Technology
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• v.10 no.2
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• pp.574-585
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• 2015

This paper aims to improve the performance of conventional direct torque control (DTC) drives proposed by Takahashi by extending the idea for 5-level inverter. Hybrid cascaded H-bridge topology is used to achieve inverter voltage vector composed of 5-level of voltage. Although DTC is very popular for its simplicity but it suffers from some disadvantages like- high torque ripple and uncontrollable switching frequency. To compensate these shortcomings conventional DTC strategy is modified for five levels voltage source inverter (VSI). Multilevel hysteresis controller for both flux and torque is used. Optimal voltage vector selection from precise lookup table utilizing 12 sector, 9 torque level and 4 flux level is proposed to improve DTC performance. These voltage references are produced utilizing a hybrid cascaded H-bridge multilevel inverter, where inverter each phase can be realized using multiple dc source. Fuel cells, car batteries or ultra-capacitor are normally the choice of required dc source. Simulation results shows that the DTC drive performance is considerably improved in terms of lower torque and flux ripple and less THD. These have been experimentally evaluated and compared with the basic DTC developed by Takahashi.