• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.4
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• pp.45-56
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• 2011

This paper is proposed artificial neural network(ANN) rotor resistance estimation of induction motor drive controlled by multi-adaptive fuzzy learning controller(AFLC). A simple double layer feedforward ANN trained by the back-propagation technique is employed in the rotor resistance identification. In this estimator, double models of the state variable estimations are used; one provides the actual induction motor output states and the other gives the ANN model output states. The total error between the desired and actual state variables is then back propagated to adjust the weights of the ANN model, so that the output of this model tracks the actual output. When the training is completed, the weights of the ANN correspond to the parameters in the actual motor. The estimation and control performance of ANN and multi-AFLC is evaluated by analysis for various operating conditions. Also, this paper is proposed the analysis results to verify the effectiveness of this controller.

• Proceedings of the KIEE Conference
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• 1989.11a
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• pp.20-24
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• 1989

The time optimal position control scheme can be repeatedly taken from the initial state of a dynamic system to a desired one as fast as possible at the industrial drives. In this case, the machine parameters will vary due to temperature, frequency, and saturation effects. In particular, the rotor resistance value changes dramatically with temperature and frequency. These changes affect the command values of the stator current components and slip speed. There is a mismatch between the commanded variables and actual variables of the induction motor drive, and this situation leads to decoupling of the vector controller from the plant, i.e the induction motor. Consequences of such decoupling include the initiation of oscillations of the rotor flux and unsuitable switching of electromagnetic torque of the induction motor servo drive. Therefore, a rotor resistance parameter compensating method for the induction motor is described.

• Journal of Power Electronics
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• v.13 no.2
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• pp.250-255
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• 2013

This paper proposes an optimal current distribution method of dual-rotor brushless DC machines (DR-BLDCMs) which have inner and outer surface-mounted permanent-magnet rotors. The DR-BLDCM has high power density and high torque density compare to the conventional single rotor BLDCM. To drive the DR-BLDCM, dual 3-phase PWM inverters are required to excite the currents of a dual stator of the DR-BLDCM and an optimal current distribution algorithm is also needed to enhance the system efficiency. In this paper, the copper loss and the switching loss of a DR-BLDCM drive system are analyzed according to the motor parameters and the switching frequency. Moreover, the optimal current distribution method is proposed to minimize the total electrical loss. The validity of the proposed method was verified through several experiments.

• Proceedings of the KIPE Conference
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• 1996.06a
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• pp.21-25
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• 1996

To control the speed of IPMSM drives it is necessary to know the speed and the rotor position. This is normally done by measurement of this values with electromechenical sensors. In this paper, a new approach to the position elimination method for the high performance variable speed IPMSM drives with the current controlled PWM technique is presented. For the high performance drive capability in the speed region, a Extended Kalman filter algorithm is adopted to estimate the rotor position as well as the angular velocity for the practical sensorless IPMSM drives. The high performance drive characteristics of the proposed method are verified using the wide simulation.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.7
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• pp.903-909
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• 2014

As a direct drive type washing machine requires two operating modes, washing and spinning modes, a design of the motor with high efficiency in each mode is not applicable to a conventional procedure. To achieve the requirements, a multi-pole outer rotor type switched reluctance motors are considered. To select a suitable motor type for the application, a static toque is compared based on the FEM analysis. The selected type is obtained for high and wide toque than other types of the motor. Further, the pole shape and arc are optimized to meet the required torque and torque ripple. To verify the proposed structure, the prototype is designed and manufactured. And the simulation and experimental results verify the validity of the proposed structure.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.5B no.1
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• pp.84-89
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• 2005

This paper presents a control algorithm for a large salient-pole synchronous motor fed by a Load Commutated Inverter (LCI). Many papers have been presented in the past few years on the justification, design, and application of variable-speed drive. The focus of this paper is on high torque operation and the estimation of initial rotor position. The results of simulation indicate that it is possible to produce the maximum torque and estimate the initial rotor position.

• Proceedings of the KIPE Conference
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• 2002.07a
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• pp.129-132
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• 2002

The first purpose of this paper is to develop the sensorless drive at adjustable speed without any mechanical position or speed sensor. For this, this research analyzes terminal voltage, finds the rotor position information and makes the source of commutations of phase current. The second purpose is to propose the sensing method of initial rotor position without instantaneous rotating. Experimental results show the validity and practical use of the proposed sensing method.

• Proceedings of the KIEE Conference
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• 1995.07a
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• pp.294-296
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• 1995

In this paper, a vector control method for a AC-Excited BLSM(Brushless Synchronous Motor) is proposed. The BLSM has a feature that separate exciter is not needed for excitation. The proposed method is described in two parts as follow, one is the design of drive and the other is a modeling for its implementation. Rotor flux is estimated using indirect sensing method based on voltage equation in the synchronously rotation reference frame. And rotor position is calculated from rotor angular velocity and stator current. Through computer simulation results of this proposed system, it is shown that the BLSM drive has a ability of precision torque control from the static and dynamic performance.

• 유체기계공업학회:학술대회논문집
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• 2004.12a
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• pp.379-384
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• 2004

A prototype of 750 kW direct-drive wind turbine generator system, KBP-750D is under development in Korea. For the gearless, direct-drive prototype a synchronous generator with permanent magnets has been developed. The upwind 3-blade type machine employs variable speed and pitch control. The operating ranges of wind and rotor speed are 3 to 25 m/s and 9 to 25 rpm, respectively. The tip speed ratio of rotor blade is 7.5, designed for power coefficient 0.47, The blade pitch and torque are controlled with the predefined torque-speed curve according to the conditions of wind and public electric grid. This paper describes the outlines of primary components of KBP-750D.

• Journal of Electrical Engineering and Technology
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• v.1 no.1
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• pp.80-84
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• 2006

The sustained oscillation of rotor speed is often experienced in PWM inverter induction motor (IM) drive systems. In this paper the oscillation is investigated from the point of view of Hopf bifurcation theory. The sufficient and necessary conditions for existence of limit cycle are introduced to determine the bifurcation set in the stator voltage versus stator frequency plane. According to the conditions it is clarified that the bifurcation set inherently exists in the instable operation of IM. Moreover, it is numerically shown that the V/f curve can be adjusted to stabilize the sustained oscillation of rotor speed.