• Proceedings of the KIEE Conference
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• 1997.07f
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• pp.2088-2090
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• 1997

This paper consists of the speed sensorless vector control of induction motors with the estimation of rotor resistance. In the application of variable-speed induction motor drives, if an inaccurate rotor resistance is used because the rotor resistance can change due to skin effects and temperature variables, it is difficult to achieve a collect field orientation. In this paper, to overcome these difficulties adaptive algorithm is designed for rotor resistance identification. The proposed adaptive algorithm for rotor resistance estimation in the synchronous reference frame is applied by sliding mode current controller satisfing persistent excitation(PE) condition. Adaptive flux observer is here used for the purpose of estimating rotor flux and speed in the speed sensorless scheme. Computer simulations are carried out to verify the validity of the proposed algorithm.

• Proceedings of the KIEE Conference
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• 1997.07f
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• pp.2095-2097
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• 1997

This paper describes a indirect sensing method for the rotor flux position of interior permanent magnet (IPM) brushless DC motors. The phase inductance of an IPM motor varies appreciably according to the rotor position. The waveform characteristics of the terminal voltage of IPM brushless DC motors is analysed and a simple and practical method for indirect sensing of the rotor position is proposed. A compact sensorless drive is implemented and tested using a 87c196mc 16-bit microcomputer. The experimental results show the validity of the proposed method and the drive works well from 500 to 7,200rpm.

• Proceedings of the KIEE Conference
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• 1997.07f
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• pp.2149-2151
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• 1997

Open loop microstepping control of two phase hybrid step motors provides enhanced step resolution, smoothness of operation, and removes most of the objectionable resonance phenomena. In this paper, we discuss the technigues about design and implementation of microstepping driver of two phase hybrid step motors.

• Proceedings of the KIEE Conference
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• 1997.07f
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• pp.1961-1963
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• 1997

A new higher reaching speed algorithm for the position control systems of the treveling wave type Ultrasonic Motors(USM) is presented. As the frictional forces of the stator materials revolves the rotor, the temperature of the contact surfaces is increased. It deteriorates the performance of control system so that the control frequency of inverter deviate from the natural resonant frequence of USM during the normal operation. In order to get higher reaching speed in the position control, we propose a novel algorithm that detect the resonant frequency of USM using the simple hardware and decision Processing. The effectiveness of proposed algorithm is verified by the experimental results.

• Proceedings of the KIEE Conference
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• 1996.07a
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• pp.172-174
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• 1996

In this paper, the characteristics of single-phase induction motors is studied using TDFE(Time Domain Finite Element) analysis. The magnetic field equation from the Maxwell's equations is solved using 2-Dimensional TDFE method, and the circuit equations from the stator and rotor are solved simultaneously. The 3-D effects, which are the end-leakage reactance and the resistance of end-rings are considered in 2-D combined equations. The proposed method is applied to the commercial single-phase induction motor. The calculated waveforms of the currents shows a good agreement with the measured ones.

• Proceedings of the KIEE Conference
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• 1996.07a
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• pp.281-284
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• 1996

Samsung Electronics has developed high performance velocity and position controllers for induction motors, and succeeded in mass production for the first time in Korea. Dynamic performance and final control accuracy of the controller are equivalent to those of AC servo motor controller. At present, we adopted the controller as spindle motor drive for Samsung CNC systems, and expect its wide use in industry as general purpose velocity and position controller for induction motor.

• Proceedings of the KIEE Conference
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• 1996.07a
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• pp.510-513
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• 1996

This paper consists of the speed sensorless vector control of induction motors with the estimation of rotor resistance. In the application of variable-speed induction motor drives, if an inaccurate rotor resistance is used because the rotor resistance can change due to skin effects and temperature variables, it is difficult to achieve a collect field orientation. In this paper, to overcome these difficulties adaptive algorithm is designed for rotor resistance identification at the beginning of the transient state. And an adaptive flux observer is used for the purpose of estimating rotor flux and speed in the speed sensorless scheme. Computer simulations are carried out to verity the validity of the proposed algorithm.

• Proceedings of the KIEE Conference
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• 1996.07a
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• pp.507-509
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• 1996

This paper is concerned with a position, control of induction motors using binary control. Due to the robustness and fast response, variable structure control is widely used for motor control field. However, the chattering phenomenon which is a drawback of VSC deteriorates the control performance and damages system components. In this paper, using binary control which has the characteristics of chattering alleviation and robust property solves this problem. The principle of binary control with inertial external loop and the design method of binary position controller are described. Also the control performance of proposed controller is confirmed by experiments.

• Proceedings of the KIEE Conference
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• 1996.07a
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• pp.133-135
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• 1996

This paper deals with the effect of teeth number variation in permanent Magnet DC motor. As teeth number varies, both flux density distribution and winding pitch are influenced, which is closely related to torque-speed characteristics, output power, and efficiency. In this study, motor design carried out using finite element method, and prototype motors were manufactured to test their performance analysis. In spite of torque ripple due to cogging effect better characteristic of machine using small teeth number was recorded than the motors with large number of rotor teeth. One of that reasons is caused by adopting large coil-length due to large number of teeth, i. e. large coil-pitch.

• Proceedings of the KIEE Conference
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• 1996.07a
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• pp.6-8
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• 1996

Induction Motors are preferred because of their ability to achieve higher power density, efficiency and reliability than permanent DC Motors for Electric Vehicle Drives. This paper describes induction motor design procedure to achieve high power density for EV using nonlinear optimization technique. Objective functions are considered to improve power density and a set of eight design variables is identified. As a numerical example, an induction motor of 15kW, 3 phase and 4 pole is designed.