• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.627-630
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• 2004

The PID type controller has been widely used in industrial application due to its simply control structure, ease of design, and inexpensive cost. However, control performance of the PID type controller suffers greatly from high uncertainty and nonlinearity of the system, large disturbances and so on. This paper presents a hybrid fuzzy logic proportional plus conventional integral derivative controller (fuzzy P+ID). In comparison with a conventional PID controller, only one additional parameter has to be adjusted to tune the fuzzy P+ID controller. In this case, the stability of a system remains unchanged after the PID controller is replaced by the fuzzy P+ID controller without modifying the original controller parameters. Finally, the proposed hybrid fuzzy P+ID controller is applied to BLDC motor drive. Simulation results demonstrated that the control performance of the proposed controller is better than that of the conventional controller.

• Proceedings of the KIEE Conference
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• 1992.07b
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• pp.685-688
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• 1992

This paper studies the commutation phenomenon in the Brushless DC Motor with the trapezoidal BEMF waveform. It is shown that the torque ripple am the speed ripple due to the phase commutation depend on driving sytem, operating speed am load condition. The effects of resistance and BEMF flat width on torque ripple are considered. Speed - torque characteristics of the motor is presented considering the phase commutation. Uncommutating current control method can attenuate the torque ripple in the low speed region, and also minimize the switching loss am switching frequency. In this paper, the commutation phenomena are verified by analytical formulation and simulation.

• Proceedings of the KIEE Conference
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• 1987.07b
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• pp.1317-1321
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• 1987

A new type of motor-driven Total Artificial Heart(TAH) system with rolling cylinder mechanism has been developed. Brushless DC motor was chosen as energy converter and controlled by PI controller according to the given velocity profile under the highly time-varying load. Computer simulation was also performed to calculate the optimal gains of PI controller which minimize the input power, one of the most important parameter in artificial heart system.

• Journal of Industrial Technology
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• v.24 no.A
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• pp.109-117
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• 2004

This paper presents a current control strategy to reduce torque ripple of Brushless DC Motor in commutation period with PWM pattern. The torque ripple is mainly caused by the inequality in the rate of change between rising current and decaying one during commutation. And also it is influenced by the shape of real back EMF. Therefore, in the proposed control strategy, considering real back EMF a compensation voltage is generated to equalize the rate of change in these commutating currents. And then, by providing the compensation voltage in commutation period with PWM pattern, the torque ripple can be reduced. The simulation and experimental results verify that the proposed method can reduce the torque and the current ripples significantly.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.202-205
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• 2008

This paper presents an optimization of permanent magnet (PM) in a brushless dc (BLDC) motor using the response surface methodology (RSM). Size and angle of the PM are optimized to minimize the cogging torque, while reducing the magnitude of harmonic at a dominant frequency and maintaining the operating torque. A fitted RS model is constructed by verifying the high reliability of the total variation and the variation of estimated error. The optimized design is validated by carrying out the reanalysis and comparing to the initial model using the nonlinear transient finite element analysis.

• Proceedings of the KIEE Conference
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• 1997.11a
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• pp.32-34
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• 1997

For a given brushless DC linear motor, we suggest the numerical prediction methods to analyze it's thrust characteristics. First, we calculate the magnetic flux density by the finite element method, and we then compute the maximum thrust with three computational methods - a Lorentz equation, a Maxwell stress method and a virtual work method. To confirm the accuracy of the computational methods, we measure the thrust of the linear motor made by our laboratory with a force-torque sensor. Also, we calculate the thrust by the measured back electromotive force. To choose the appropriate method for a specified application, we compare the maximum thrusts of the computational method and the calculation by the back electromotive force with the measured one. We conclude that the Maxwell stress method is turned out the best because it has the most accurate results among three computational methods and it is more convenient than the calculation method by the back electromotive force.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.916-917
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• 2015

This paper deals with electromagneitc characteristics analysis of high-speed brushless DC motor. First, under same rated and restricted conditions, four models which have different slot combinations each other are designed using 2-d finite element (FE) analyses. Designed models are analyzed and compared in terms of core loss, copper loss, eddy-current loss, etc. On the basis of analysis results, it is found that the motor with a 2-pole PM rotor and a 6-slot stator has most outstanding performances in electromagnetic aspects.

• Proceedings of the KIPE Conference
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• 2006.06a
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• pp.16-18
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• 2006

This paper presents a sensorless speed control of Brushless DC motor using terminal voltage of one phase. Rotor position information is extracted by indirectly sensing the Back-EMF from only one of the three terminal voltages for a three phase BLDC motor. This is a advantage for the cost saving and size reduction. Also, it can be substituted for conventional Hall-IC or encoder applied to position control.

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.629-631
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• 2000

This paper deals with the design of a inner rotor type Brushless DC (BLDC) motor for Electric Power Steering to reduce the cogging torque. The effect of the design parameters on the characteristic and cogging torque is analyzed by Finite Element Method (FEM). The considered design parameters are as follows : the number of pole and slot. dead-zone and skew angle. and teeth shape. The winding resistance of each motor is calculated and the characteristic curve is derived from considering reactance drop voltage for original model.

• Journal of Institute of Control, Robotics and Systems
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• v.13 no.6
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• pp.589-595
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• 2007

This paper presents a new method on controller design of brushless dc motors. In such drives the current ripples are generated by motor inductance in stator windings and the back EMF. To suppress the current ripples the current controller is generally used. To minimize the size and the cost of the drives it is desirable to control motors without the current controller and the current sensing circuits. To estimate the motor CUlTent it is modeled by a neural network that is contigured as an output-error dynamic system. The identified model is essentially a one step ahead prediction structure in which past inputs and outputs are used to calculate the current output. Using the model, a state feedback controller to compensate the effects of disturbance has been designed. The controller is implemented by a 16-bit microprocessor and the effectiveness of the proposed control method is verified through experiments.