• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.9 no.4
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• pp.78-85
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• 1995

This paper covers stability and stabilization of Multi-Excited Induction Motor used in numberous electric equipment system of industrial field. The induction motor with multi-excitation has tow sets of three-phase system : One is connected to the AC source to supply most power required at the load, and the other is to the inverter for variable frequency and/or magnitude of voltage. The conventional induction motor is operated under single excitation mode only, that is called induction mode. But in multi-excited induction motor both the induction mode and the synchronous mode are possible, and the proposed multi-excited induction motor can be driven as a synchronous motor by the extra three-phase input. At the synchronous mode the efficiency is improved so higher than that at induction mode or conventional induction motor. The rating of the inverter used for speed control of numberous electric equipment system can be reduced upto one-tenth of that for conventional induction motor. Also the cost and maintenance fee of multi-excited induction motor can be reduced compared to any other motor.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.4
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• pp.517-522
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• 2019

This paper proposes a new motor parameter estimation method. Because the proposed method is based on difference equations, it does not affect the error in the voltage magnitude so called dead-time effect. Information on the motor constant may be needed to improve the motor control performance. For example, a control technique called DTC (Direct Torque Control) requires a motor constant when calculating the torque and flux magnitude. As another example, in the case of predictive control, information on the motor parameters is required to generate voltage references. Because the constant of the motor fluctuates according to the driving environment, it is essential to estimate the correct motor constant because the control performance is degraded when incorrect motor information is used. In the proposed scheme, the motor constant estimated based on the voltage difference equation is obtained using the RLS (Recursive Least Square) technique. The RLS algorithm is applied to obtain the value through an iterative calculation so that the estimation performance is robust to noise. The simulation results carried out with surface mounted permanent magnet motors confirmed the validity of the proposed method.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.898-899
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• 2015

This paper present a transient experiment to verify the performance of limited angle torque motor(LATM) designed using electromagnetic transient analysis. LATM requires access to the transitional state to the torque performance evaluation. Because LATM moves the rotor using a magnetic torque generated by the interaction of the permanent magnet and the armature winding. A separate control is not applied, it is switched on at the same time under the conditions that the current applied to the armature winding. It was compared to the transient analysis of the experimental data of LATM for the verification of approach method in the transitional state.

• Proceedings of the KIPE Conference
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• 2006.06a
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• pp.485-487
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• 2006

Speed and torque controls of permanent magnet synchronous motors are usually attained by the application of position and speed sensors. However, speed and position sensors require the additional mounting space, reduce the reliability in harsh environments and increase the cost of a motor. Therefore, many studies have been performed for the elimination of speed and position sensors. This paper investigates an Improved sliding mode observer for the speed sensorless control of a permanent magnet synchronous motor. The proposed control strategy is the sliding mode observer with a variable boundary layer for a low-chattering and fast-reponse control. The proposed algorithm is verified through the simulation and experimentation.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.77-78
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• 2006

Post industrial technologies have improved human standard of living, however, a host of negative environmental consequences from the unlimited industrial appetite have posed serious global challenges. Remanufacturing is an industrial manufacturing process that is to restore old products to perform like a new and to save energy, natural resources, landfill space and to reduce air pollution by less re-smelting. By extending product life cycle, remanufacturing gives us enormous opportunities for sustainable development of our society. This paper introduces current state of the art and future perspective in the field of automotive remanufacturing focusing on alternator and start motor. The results could be used as a basic information for further remanufacturing applications in Korea.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.908-909
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• 2011

전기 자동차용 전동기는 고출력, 소형화, 제어의 용이성 등으로 인해 영구자석형 전동기를 많이 채택하고 있는 추세이다. 이 중 IPM 전동기는 출력 특성 및 제어의 용이성으로 인해 많이 사용되고 있다. 특히 IPMSM을 EV용으로 적합하게 사용할 수 있도록 학계 및 산업계에서 전동기의 출력 개선, 열적 문제 해결, 구조 강도 문제 해결 등의 노력을 진행해왔다. 이 논문에서는 항복 강도를 고려하여 영구자석 센터 포스트 간격을 변화시키면서 전동기의 출력 특성을 살펴보았다.

• Proceedings of the KIEE Conference
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• 1996.07a
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• pp.267-269
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• 1996

Servo systems became indispensable to applications such as industrial robots and numerically controlled machinery. Especially, induction motor drives are widely used as ac-servo system owing to the fact that it is maintenance-free. At the present time, Quick torque control methods such as vector control have been employed that enables an induction motor to attain as quick torque response as a dc motor. However, these methods can not be realized without knowing several motor parameters accurately, because the methods need them to calculate flux or voltage command. Most of all, secondary resistance has to be identified accurately, because it's value varies greatly for operation of induction motors. In this paper, a new identification method of secondary resistance based on quick torque control system of induction motors is proposed. The proposed method is derived theoretically from motor circuit equation and can be realized very simply by detecting primary current and voltage command of the motor. Through the numerical simulation considered using PWM inverter, the validity of the proposed method was successfully confirmed.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.25 no.6
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• pp.414-419
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• 2015

Recently, commercial ships and other specialized vessels with electric propulsion system employ variable speed induction motor as its prime mover. The wide application of electrical motors also includes being the main drive system in most industrial machineries. However, during its start-up, shutdown, and brake switch operation, excessive torque variation are generated. As such, flexible coupling are installed in order to reduce the transmitted torque fluctuation to the driven side. In this paper, the pulse torque generated by an variable speed induction motor was analyzed theoretically and through measurement of torsional vibration. Induction motor with inverter on marine propulsion system and industrial compressor were used as experimental subjects. The study confirmed that pulse torque are generated regardless of motor speed and interpreted as a vibration source of the whole system. Results presented herein can be adopted as the basis in future amendment of inspection classifying body regulations.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.6 no.5
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• pp.432-438
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• 2005

In this paper, the high precision position control of AC Servo motor for semiconductor equipment is studied. The control system was implemented using TI DSP TMS320F2812 which has 150 MIPS speed for next generation motor control. The controlled 100W PMSM motor has 2,500 ppr optical incremental encoder. The control system has speed controller and current controller to control the motor position. The encoder pulses are divided into 4 times, which has 10,000 ppr and the motor system has the position accuracy of 1/10,000. If the resolution of the encoder is increased, the resolution of the position control will be increased.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.1
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• pp.144-152
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• 2017

A motor model and off-line diagnosis method of the induction motor having an interturn fault(ITF) is studied. The proposed method is based on the magnitude comparison of the six impedance in the d-q plane. To prove the impedance unbalance, the induction motor model is presented with an ITF circuit loop with a fault resistance. Then, six impedance components in the stationary d-q plane are defined depending on the connected phase windings. Finding the maximum and minimum magnitude of the six impedance, the ITF and the faulty phase can be founded. To verify the proposed method, the experimental results with an induction motor having an ITF are shown.