• Proceedings of the KIEE Conference
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• 1996.07a
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• pp.470-472
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• 1996

In this paper, we proposed a new speed control algorithm based on the least-order observer theory. The proposed system using the new algorithm can estimate the instantaneous speed accurately even at low speed by using a load torgue observer estimating the torgue component of indirect-vector controlled induction motor. Thus the stable characteristics of speed control are possible at low speed even in the case of using low-resolution rotary encoder. Also, the system becomes robust against disturbance by feedforward control the load torque estimated automatically at the speed observer.

• Proceedings of the KIPE Conference
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• 2004.07a
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• pp.303-307
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• 2004

This paper presents a new speed control scheme of the spindle induction motor (IM) using fuzzy-logic control in field weakening region. The implementation of the proposed FLC-based spindle IM are investigated and compared to those obtained from the conventional PI controller based drive system, we have confirmed good simulation and experimental results at different dynamic operating conditions such as sudden change in command speed, step change, etc.

• Proceedings of the KIPE Conference
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• 2003.11a
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• pp.73-76
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• 2003

This paper proposes a maximum output power control of grid-connected wind power generation system using cage-type induction generators. For generator control, indirect vector control is used, where d-axis current controls the excitation level and q-axis current controls the generator speed. The generated power flows into the utility through the grid-side converter, by which the do link voltage is controlled to be constant and the ac current is controlled in sinusoid and. The generator speed is adjusted according to wind speed for extracting maximum power generation. Experimental results are shown to verify the validity of the proposed scheme.

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.1117-1119
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• 2000

An easier implementation method of the field oriented control of induction machine using Matlab/Simulink dSpace board is proposed in this paper. Space Vector PWM and Indirect Fied Oriented Control Algorithm is designed for the help of Simulink. And this system is simultaneously simulated and experimented in Matlab/Simulink environment with dSpace borad (DS1102). It is possible that Matlab and dSpace board compiler can make $'^*.c'$ and $'^*.obj'$ file of models designed in Matlab/Simulink environment automatically. Experimental results are given.

• Proceedings of the KIEE Conference
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• 2006.10c
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• pp.282-284
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• 2006

Generally PI controller is used to control the speed of an induction motor. It has the good performance of speed control in case of adjusting the control parameters. But it occurred the problem to change the control parameters in the change of operation condition. In order to solve this problem, Fuzzy control or Artificial neural network is introduced in the speed control of an induction motor. However, Fuzzy control have the problems as the difficulties to change the membership function and fuzzy rule and the remaining error. Also Neural network has the problem as the difficulties to analyze the behavior of inner part. Therefore, the study on the combination of two controller is proceeded. In this paper, Speed controller of an induction motor based fuzzy-neural network is proposed and the speed control of an induction motor is performed using the proposed controller. Through the experiment, the fast response and good stability of the proposed speed controller is proved.

• Proceedings of the KIEE Conference
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• 1996.07a
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• pp.285-288
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• 1996

Iron loss is a possible source of performance deterioration, especially for a torque regulation, in field oriented induction machine. In this paper, study on the model of an induction machine with iron losses, a flux estimation strategy, the design of direct and indirect field oriented controller, a precise torque regulation scheme and the determination of a core lost resistance are discussed. Simulation and experimental results are also included and show the effectiveness of the proposed analysis and the proposed control strategy.

• Proceedings of the KIEE Conference
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• 2003.04a
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• pp.338-340
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• 2003

This paper proposes a stand-alone adjustable speed wind Power generation system using a cage-type induction generator. Indirect vector control is used, where the q-axis current controls the generator speed and the d-axis current controls the excitation level. The generator speed is adjusted according to the wind speed so as to produce the maximum output power. The generated power is charged in the battery bank through ac/dc PWM converter. The proposed scheme has been verified by the experimental results.

• Proceedings of the KIEE Conference
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• 1999.07f
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• pp.2742-2744
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• 1999

In this paper, an auto-tuning method for fuzzy logic controller based on the genetic algorithm is presented. In the proposed method, normalization parameters and membership function parameters of fuzzy controller are translated into binary bit-strings, which are processed by the genetic algorithm in order to be optimized for the well-chosen objective function (i.e. fitness function). To examine the validity of the proposed method. a genetic algorithm based fuzzy controller for an indirect vector control of induction motors is simulated and experiment is carried out. The simulation and experimental results show a significant enhancement in shortening development time and improving system performance over a traditional manually tuned fuzzy logic controller.

• Proceedings of the KIEE Conference
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• 1999.07f
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• pp.2770-2772
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• 1999

This paper discusses the basic principle of vector control applied to induction motors. A indirect strategy for impressed stator currents control is used for system modeling. IRFOC for induction motor was modelled using "Matlab with Simulink" IRFOC be applied to 15kW induction motor is simulated in different conditions; step changes in torque at a fixed reference speed, and cyclic change of speed reference. Simulation result considering the variation of stator, rotor resistance includes the response of speed, torque and rotor d-q fluxes.

• Bulletin of the Korean Mathematical Society
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• v.38 no.1
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• pp.29-53
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• 2001

This note presents a an indirect adaptive control scheme for first-order continuous-time systems. The estimated plant model is controllable and then the adaptive scheme is free from singularities. The singularities are avoided through a modification of the estimated plant parameter vector so that its associated Sylvester matrix is guaranteed to be nonsingular. That properties is achieved by ensuring that the absolute value of its determinant does not lie below a positive threshold. A modification scheme based on the achievement of a modified diagonally dominant Sylvester matrix of the parameter estimates is also given as an alternative method. This diagonal dominance is achieved through estimates modification as a way to guarantee the controllability of the modified estimated model when a controllability measure of the ‘a priori’ estimated model fails. In both schemes, the use of a hysteresis switching function for the modification of the estimates is not required to ensure the nonsingularity of the Sylvester matrix of the estimates.