• Journal of Electrical Engineering and Technology
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• v.12 no.1
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• pp.100-109
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• 2017

This paper proposes performance improvement schemes for sensorless PMSM control drive using a four-switch three-phase inverter (so-called B4 inverter). In the proposed scheme, the back-EMF estimation-based sensorless control algorithm is used to control the brushless PMSM without position sensors. In order to have stable operation, this paper presents a gain adjustment scheme that compensates the reduction of stable sensorless operation range as long as the rotor speed increases. In B4 topology, the center point of dc-link capacitors is connected to 3-phase load, and it is prone to have the load current distortion. Hence, to mitigate this problem, a distortion compensation scheme by modifying voltage commands using measured dc-link potentials is proposed in this paper. The validity of the proposed method is evaluated by simulations and experiments.

• Journal of Power System Engineering
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• v.19 no.4
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• pp.89-96
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• 2015

This paper investigates some strategies to overcome the chattering problem of the conventional sliding mode observer (SMO) and to improve the rotor position estimation performance for full range sensorless control of a PMSM. An adaptive observer gain based on the Lyapunov's stability criterion and a cascade low pass filter with advanced phase delay compensation were proposed to reduce the chattering problem and to strengthen the filtering capability of the SMO. Several cases studies through experiments were carried out to confirm conventional SMO's problems and effectiveness of the proposed strategies. The experimental results show that the proposed method gives precise estimation on speed and rotor position when the motor rotates on 2% of its rated speed.

• Proceedings of the KIEE Conference
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• 1998.07f
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• pp.2094-2096
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• 1998

In this paper, a new speed estimation method using neural networks is proposed and speed sensorless vector control is realized with the estimated speed. The effectiveness and the usefulness of the proposed algorithms are thoroughly verified with the experiments on the fully-digitalized 2.2kW induction motor drive systems.

• Proceedings of the KIEE Conference
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• 2001.04a
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• pp.308-310
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• 2001

This paper investigates a novel speed sensorless control method of I.M considering the secondary resistance identification based on the transientless torque control technique. Especially, this paper aimed at the identification of the secondary resistance simultaneously with speed estimation superposing of sinusoidal flux wave to a constant flux value. Furthermore, the secondary flux with some frequency is controlled independently on torque control. The proposed speed estimation method is derived from a motor circuit equation theoretically and also it can be conducted easily by detecting primary motor currents and primary voltage commands at every sampling time. Some numerical simulations with the assumption of using a pulse width modulation(PWM) voltage source inverter are performed to verify the proposed method.

• Proceedings of the KIEE Conference
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• 1998.07f
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• pp.2005-2007
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• 1998

The rotor speed flux information most important in the speed sensorless vector c So in the paper used current voltage model for flux information in a induction motor. Voltage realized low pass filter insted of integrator, c model realized used of current equation. And cur voltage model estimated flux compoed of Pl cont For conpensation of estimated flux error conpansation algorithm using exactly, rapidly flux obtained for conpensation of estimated flux Proposed control system used TMS320C31 DS high speed processing. The effectiveness of proposed method is verified by simulation experimental results. This method shows h characteristic speed estimation highly flux esti and stable, robust character of load regulation.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.53 no.3
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• pp.145-153
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• 2004

A nonlinear adaptive speed observer is designed for the sensorless control of induction motors. In order to design the speed observer, the measurements of the stator currents and the estimates of the rotor fluxes are used. The sliding mode cascade observer is designed to estimate the time derivatives of the stator currents. The open-loop observer is designed to estimate the rotor fluxes and its time derivatives using the stator current derivatives. The adaptive observer is also designed to estimate the rotor resistance. Sequentially, the rotor speed is calculated using these estimated values. It is shown that the estimation errors of the corresponding states and the parameters converge to the specified residual set. It is also shown that the speed controller using these estimates is performed well. The simulation examples are represented to investigate the validity of the proposed observers for the sensorless control of induction motors.

• Proceedings of the KIPE Conference
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• 1998.07a
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• pp.217-220
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• 1998

In this paper, for high performance as drive, in the speed sensorless vector control of induction motor, introduced flux estimator of voltage model and error compensation algorithm using closed loop integration method, and then we proposed a improved flux estimation method of high accuracy. And the rotor speed is estimating using the stator current and the estimated flux, it is used speed information. The proposed scheme is verified through digital simulations and experiments for 3.7[kW] induction motor and shows good dynamic performance.

• Proceedings of the KIEE Conference
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• 1996.07a
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• pp.510-513
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• 1996

This paper consists of the speed sensorless vector control of induction motors with the estimation of rotor resistance. In the application of variable-speed induction motor drives, if an inaccurate rotor resistance is used because the rotor resistance can change due to skin effects and temperature variables, it is difficult to achieve a collect field orientation. In this paper, to overcome these difficulties adaptive algorithm is designed for rotor resistance identification at the beginning of the transient state. And an adaptive flux observer is used for the purpose of estimating rotor flux and speed in the speed sensorless scheme. Computer simulations are carried out to verity the validity of the proposed algorithm.

• Journal of Power Electronics
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• v.16 no.4
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• pp.1346-1354
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• 2016

This paper proposes a design guideline for the feedback gain of the adaptive full-order observer in the speed sensorless control of induction machines. The performance of the adaptive full-order observer is dependent on its feedback gain. This paper presents a pole placement method for the observer feedback gain design to improve the estimation performance of the speed adaptive observer. In the proposed method, the observer poles can be chosen independently of the induction motor poles. Instead, they can be positioned according to the operating speed. An analysis and experimental results obtained with the proposed method reveals better performances under general operating conditions.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.54 no.2
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• pp.101-109
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• 2005

The newly developed speed sensorless control scheme is proposed to estimate both motor speed and rotor resistance simultaneously using variable rotor flux. The rotor flux is given as sinusoidal waveform with an amplitude and a frequency without affecting precise torque control. Especially the proposed method makes the simultaneous estimation of rotor resistance and speed with high precision even though at the low speed area including a few rpm. Moreover, on-line identification of rotor resistance can be performed simply without calculating troublesome trigonometric functions and complicated integral computation. Therefore, the proposed system can be accomplished by using very cheap microprocessors for several applications. The results of the numerical simulations and experiments demonstrate that this method is effective to estimate the speed and on-line identification of rotor resistance for sensorless induction motors.