• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.61-62
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• 2011

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.8
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• pp.82-87
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• 2011

Induction motor is most widely used as the driving power in the industrial site. Induction motor current is composed of two parts, magnetizing current and load current. Load current uses energy what is doing the work. Load current varies with load variance but magnetizing current is constant, regardless of load variation. Magnetizing current needs for establishing the rotating magnetic field of induction motor and lags behind the voltage. Generally capacitor is used for power-factor compensation of inductive load. Self-excitation occurs when the capacitive reactive current from the capacitor is greater than the magnetizing current of the induction motor. When this occurs, excessive voltages can result on the terminals of the motor. This excessive voltage can cause insulation degradation and ultimately result in motor insulation failure. In this paper, we analyzed that how the magnetizing current and condenser current is operating at the allowable limit by the load variation. Condenser current is below allowable limit of magnetizing current but magnetizing current is above allowable limit at the lower load operation condition.

• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.1165-1168
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• 2002

This paper presents a neural network based self-tuning fuzzy PID control scheme with variable learning rate for sensorless vector controlled induction motor drives. MRAS(Model Reference Adaptive System) is used for rotor speed estimation. When induction motor is continuously used long time. its electrical and mechanical parameters will change, which degrade the performance of PID controller considerably. This paper re-analyzes the fuzzy controller as conventional PID controller structure, introduces a single neuron with a back-propagation learning algorithm to tune the control parameters, and proposes a variable learning rate to improve the control performance. The proposed scheme is simple in structure and computational burden is small. The simulation using Matlab/Simulink and the experiment using DS1102 board show the robustness of the proposed controller to parameter variations.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.30B no.9
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• pp.122-132
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• 1993

In this paper, a self tuning control algorithm is proposed for the high performance drive of DC servo motor, which is adequate to the servo system having frequent load variation. In order to realization of the algorithm, the control system is developed using a fixed point high speed digital signal processor. TMS320C25. Control algorithm is composed of two parts. One is estimation law part using recursive least mean square method, the other is control law part using minimum variance control method. For the purpose of easiness of applying adaptive algorithm, developed control system is based o PC-DSP structure which can develop, debug programs and monitor the dynamic behaviors,etc. Through computer simulation and experimental results, it was verified that proposed control system could estimate system parameters and was robust to the variation of the load and as a result, was adequate to the servo motor drives.

• Proceedings of the KIEE Conference
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• 1999.11c
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• pp.488-490
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• 1999

This paper describes the design of self-tuning speed controller for DC motor drive system using RLS(Recursive Least Squares) algorithm and Pole-Placement method. The model parameters, related to inertia and damping coefficient of motor, are estimated on-line by using RLS estimation algorithm. And a control signal is calculated by using pole placement method. Simulation and experimental results show that the proposed controller possesses excellent adaptation capability than a conventional PI/IP controller under parameter change.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10a
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• pp.987-992
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• 1992

In recent years, induction motor is applied for several industrial actuatung parts instead of direct current motor because of the robust construction, nonexpensive and maintenance-free actuator etc. and having capability of speed control according to development of power electrounics and microprocessor techniques. In the paper, a microprocessor-based digital control approach for spped control of induction motor system is presented by considering a simple modelling equation as the system expression equation of induction motor and using the self tuning control and torque effdforward control method. As the model equation of the induction motor system, we use a second order differential equation which is well known in the modeling equation is induced form the control theory stand point such tath we can describe usually the motor system connected by inverter, generator and load etc. The effectiveness of the control system composed by the above mentioned design concept is illustrated by the expermental result in the presence of step reference change and generator load variation.

• Proceedings of the KIEE Conference
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• 1995.11a
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• pp.24-26
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• 1995

The Development of A.C. Induction Motor for Railway Rolling Stock. The traction motor is designed as 4-pole induction motor with self ventilation. The winding insulation is throughout of materials of class C. The rotor is designed as a squrrel rotor with copper bar and casting. The rotor speed is detected by means of a pulse generator. The newer tection motor have no casting(frame). Punched-in holes make up the air duct and transfer the heat losses in complete. Maximim motor rpm is higher due to rotor construction. New is the entry of water-cooled traction motors in urban, However the water cooling design in - unfortunately - not applicable in traction motor.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.32 no.10
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• pp.850-855
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• 2008

This paper suggests a new linear motor which is able to levitate as well as move its mover without any linear bearing or even additive windings. Its structure is very similar to a well-known both-sided linear motor which consists of two stators and a common mover. And the movement principle is the same with that of conventional linear motor. But unlike the conventional one, the amplitudes of phase currents are controlled to levitate the mover. In this paper, the structure and principle of the suggested bearingless linear motor are introduced in detail and its feasibility is experimentally investigated. Using the prototype and a very simple controller, we succeeded in the levitation and linear movement of the mover at a time.

• Transactions of the Korean Society of Automotive Engineers
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• v.20 no.1
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• pp.8-13
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• 2012

In this paper, Hybrid Electric Vehicle is directly designed and manufactured for base study of HEV's system and Green Car. Foundation design consists of power train design and the frame design. The power train concept includes motor, engine, generator and battery. And the concept of the frame is the single-seat of this self-made HEV. A frame installed in hybrid system contains suspension, steering wheel, seat, accelerating pedal, brake pedal, clutch handle and various chassis parts with bearings. Electromagnetic clutch is equipped to transmit engine power to drive axle. The control algorism make using LabVIEW to control of an engine and a motor depending on drive condition. A parallel type hybrid system is manufactured to control operation of a motor and an engine depending on vehicle speed.

• Proceedings of the KIEE Conference
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• 2004.10a
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• pp.173-175
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• 2004

This paper presents a novel design of a self tuning PI controller of induction motor using fuzzy control. In this approach, the fuzzy tuning of a PI controller gains is achieved through fuzzy rules deduced from many robustness simulation tests applied to several induction motors, for a variety of operating conditions such as response to speed command from standstill, step load torque application and speed variations, with nominal parameters and an changed rotor resistance, self inductance and inertia. Simulation results on a speed controller of induction motor are presented to show the effectiveness of the proposed gain tuner. And this controller is better than the fixed gains one in terms of robustness, even under great variations of operating conditions and load disturbance.