• Journal of Electrical Engineering and Technology
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• 제7권2호
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• pp.200-206
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• 2012

In order to develop a deep-underground great train express (GTX) in South Korea, the specifications decision and development of a traction control system (including an inverter and a traction motor), which considers a variety of route conditions, must be advanced. In this study, we examined the running resistance properties of a high-speed traction system based on a variety of tunnel types and vehicle organization methods. Then, we studied the power requirements necessary for the traction motor to maintain balanced speed in the high-speed traction system. From this, we determined the design criteria for the development of a high-speed traction system for use in the deep-underground GTX. Finally, we designed a linear induction motor (LIM) for a propulsion system, and we used the finite element method (FEM) to analyze its performance as it travelled through deep-underground tunnels.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1993년도 하계학술대회 논문집 B
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• pp.1020-1022
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• 1993

The speed control associated with do send motors for direct-drive applications of mobile robot is considered. In odor to the high-performance operation of dc servo motor, drive circuits is controlled Pulse Width Modulations. In this case, PWM driving circuit has nonliner charactristics. This circuit composed of H-type bridge with freewheeling diodes in odor to deal with storage energy of motor's inductance and also control method is developed. At resultes, speed charactristics of motor is shown lineristics. In oder to speed control of motor. The opertion of phase-locked servo system is described and a linear discrete model is developed to their behavior. Thise model discussed are the design problems, speed variation.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1996년도 창립기념 전력전자학술발표회 논문집
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• pp.1-4
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• 1996

The purpose of this treatise is to estimate speed of an induction motor and realize a robust speed control system with estimated speed in field-weakening region. A speed estimation is based on Model Reference Adaptive System(MRAS) technique and two flux estimator are designed to be robust against parameter variation. The MRAS-based overall control scheme has been implemented on 7.5kW Spindle induction motor control system. And it is verified that the proposed control scheme is very stable and robust in field-weakening region.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2001년도 학술대회논문집
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• pp.181-185
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• 2001

This paper presents a digitally speed sensorless control system for induction motor with direct torque control (DTC). The drive is based on Mode1 Reference Adaptive System (MRAS) using state observer as a reference model fat flux estimation. The system are closed loop stator flux and torque observer for wide speed range that inputs are currents and voltages sensing of motor terminal, model reference adaptive control (MRAS) with rotor flux linkages for the speed turning aignal at low speed range, two hysteresis controllers. The Proposed system is verified through simulation.

• 한국기계가공학회지
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• 제11권2호
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• pp.105-111
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• 2012

High speed machining is the core technology that influences the performance of machine tools, and the high speed motor spindle is widely used for the high speed machine tools. The important problem in high speed spindle is to minimize the thermal effect by motor and bearing and frequency effect. This paper presents the thermal characteristic analysis and frequency experiment for a high speed spindle considering the flow rate of cooling oil. A high speed spindle is composed of angular contact ceramic ball bearings, high speed built-in motor, oil cooling jacket and so on. The thermal analyses of high speed spindle need to minimize the thermal effect and maximize the cooling effect and they are carried out under the various cooling conditions. Heat generations of the bearing and the high speed motor are estimated from the theoretical and experimental data. To find out the characteristic of vibration, the high speed spindle is excited in operational range. This result can be applied to the design and manufacture of a high speed tapping spindle.

• 유공압시스템학회논문집
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• 제2권2호
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• pp.8-13
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• 2005

This paper investigates a fast, accurate and inexpensive hydraulic motor speed control system using high speed on-off solenoid valves. In order to retain the advantages of the two position valve and obtain better performance, the valves are operated by pulse width modulation(PWM) control. PWM signal is generated from a LabWIEW program in microcomputer in order to set up various duty ratio and frequency of carrier wave in PWM signal with varying system parameters. As the results of experiments, the speed control of a hydraulic motor was successfully implemented using on-off solenoid valves. In order to attenuate the pressure ripple and speed variation due to discontinuously controlled flow through the on-off valves, a resonator hose fabricated for automobile power steering system was connected between the valve and a hydraulic motor. From experimental results obtained in the hydraulic motor system with a resonator hose, it was ascertained that the resonator hose showed excellent performances in reducing pressure ripple and motor speed variation.

• Journal of Magnetics
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• 제21권3호
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• pp.405-412
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• 2016

In general, surface mounted PM synchronous motors (SPMSMs) are mainly adopted as a driving motor for high-speed applications, because they have high efficiency and high power density. However, the SPMSMs have some weak points such as the increase of magnetic reluctance and additional losses as a consequence of using a non-magnetic sleeve. Especially, the magneto-motive force (MMF) in the air-gap of the SPMSMs is weakened due to the magnetically increased resistance. For that reason, a large amount of PM is consumed to meet the required MMF. Nevertheless, it cannot help using the sleeve in order to maintain the mechanical integrity of a rotor assembly in high-speed rotation. Thus, in this paper, a multi-layer interior PM synchronous motor (IPMSM) not using the sleeve is presented and designed as an alternative of a SPMSM. Both motors are evaluated by test results based on a variety of characteristics required for an air blower system of a fuel cell electric vehicle.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제48권7호
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• pp.357-362
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• 1999

This paper presents a speed control method for the capacitor-run induction motor. The equivalent circuit of the motor is analyzed using the forward(Positive sequence) and backward(negative sequence) components, and simple circuit equations are obtained. Simulations for the speed control are performed by adjusting the voltage magnitude of the auxiliary winding. A prototype system has been implemented which consists of an inverter and a controller with TMS320C31 digital signal processor. The experimental results using 1/4hp capacitor-run induction motor show a good agreement with analyses.

• Journal of Electrical Engineering and Technology
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• 제2권4호
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• pp.500-504
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• 2007

In this paper, the induction motor rotor fault diagnosis system using current signals, which are measured using axis-transformation method, and speed, which is estimated using current information, are presented. In inverter-fed motor drives unlike line-driven motor drives the stator currents have numerous harmonics components and therefore fault diagnosis using stator currents is very difficult. The current and speed signal for rotor fault diagnosis needs to be precise. Also, high resolution information, which means the diagnosis system, demands additional hardware such as low pass filter, high resolution ADC, encoder and etc. Therefore, the proposed axis-transformation and speed estimation method are expected to contribute to low cost fault diagnosis systems in inverter-fed motor drives without the need for an encoder and any additional hardware. In order to confirm validity of the developed algorithms, various experiments for rotor faults are tested and the line current spectrum of each faulty situation using Park transformation and speed estimation method are compared with the results obtained from fast Fourier transforms.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 B
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• pp.921-923
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• 2001

In the field of factory automation, single phase induction motors are frequently used for speed control application because of its simplicity and low cost. In this paper, we compare the performances of a single phase induction type speed control motor with a BLDC motor. From the experimental results in the controllable torque-speed load range, the efficiency characteristics and safe operation load areas are compared for each type sample motor.