• International Journal of Control, Automation, and Systems
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• v.3 no.4
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• pp.612-619
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• 2005

A robust adaptive speed sensorless induction motor direct torque control (DTC) using a neural network (NN) is presented in this paper. The inherent lumped uncertainties of the induction motor DTC system such as parametric uncertainty, external load disturbance and unmodeled dynamics are approximated by the NN. An additional robust control term is introduced to compensate for the reconstruction error. A control law and adaptive laws for the weights in the NN, as well as the bounding constant of the lumped uncertainties are established so that the whole closed-loop system is stable in the sense of Lyapunov. The effect of the speed estimation error is analyzed, and the stability proof of the control system is also proved. Experimental results as well as computer simulations are presented to show the validity and efficiency of the proposed system.

• Journal of Power Electronics
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• v.5 no.4
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• pp.282-288
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• 2005

In this paper, a new speed sensorless induction motor scheme which can estimate rotor speed and rotor resistance simultaneously is presented. The rotor flux with a low frequency sinusoidal waveform is used to conduct on-line simultaneous estimation of the rotor speed and rotor resistance. Hence the proposed sensorless control method is robust to rotor resistance variations. Also, the control scheme has no current minor loop to determine voltage references. It contributes to good control performance at low speeds. Some simulation results supported by experiments are given to show the effectiveness of this method.

• Proceedings of the KIEE Conference
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• 1998.11a
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• pp.171-175
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• 1998

This paper proposes a speed sensorless vector control of induction motor using a minimum-order EKF(extended kalman filter). Minimum-order EKF has the advantage of reducing the computational estimation cost because the stator current is not estimated. EKF does not deteriorate the performance of the overall speed control system, even though the measurements are relatively noisy. The estimated rotor speed is used for vector control and overall speed control. Computer simulations of the speed sensorless vector control are carried out to test the usefulness of the minimum-order EKF algorithm.

• Journal of Power Electronics
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• v.12 no.1
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• pp.75-82
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• 2012

Elimination of rotor position sensors mechanically coupled with the rotor shaft is attractive to variable speed drives primarily due to increased system reliability and cost reduction. In this regard, search for a simple and robust position sensorless control has been intensified in past few years specifically for low-cost, high-volume applications such as home appliances. This paper describes a new parameter insensitive position sensorless control for switched reluctance motor (SRM) drives satisfying such a need in this market segment. Two consecutive switch-on times of the controllable switch in hysteresis current control are compared to estimate the rotor position and speed. The proposed sensorless control algorithm is very simple to implement since it does not depend on extensive computation or any additional hardware. In addition, the proposed method is robust in that its dynamic performance is least affected by system parameter variations. The proposed approach is demonstrated on a single-controllable-switch-converter-driven SRM with two-phases that lends itself to a system with low cost and compact packaging which comes close to the intended applications. Analysis and simulation results followed by experimental verification are presented to demonstrate the feasibility of the proposed sensorless control method.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.11
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• pp.2474-2479
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• 2012

A sensorless vector control of an induction motor provides a good performance in the middle and high speed region. However, in the low speed region, it is very difficult to implement the sensorless vector controller because the feeding voltage measured by the motor is very low. In this paper, to improve the performance of a sensorless vector control of an induction motor in the low speed region under 3Hz, we proposed the fuzzy logic controller using the zooming algorithm. To verify the performance of the proposed controller, an experiment has been performed.

• Journal of Power Electronics
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• v.16 no.6
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• pp.2173-2181
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• 2016

Permanent magnet synchronous motors (PMSMs) have higher torque and superior output power per volume than other types of AC motors. They are commonly used for applications that require a large output power and a wide range of speed. For precise control of PMSMs, knowing the accurate position of the rotor is essential, and normally position sensors such as a resolver or an encoder are employed. On the other hand, the position sensors make the driving system expensive and unstable if the attached sensor malfunctions. Therefore, sensorless algorithms are widely researched nowadays, to reduce the cost and cope with sensor failure. This paper proposes a sensorless algorithm that can be applied to a wide range of speed. The proposed method features a robust operation at low-speed as well as high-speed ranges by employing a gain adjustment scheme and intermittent voltage pulse injection method. In the proposed scheme the position estimation gain is tuned by a closed loop manner to have stable operation in tough driving environment. The proposed algorithm is fully verified by various experiments done with a 1 kW outer rotor-type PMSM.

• Journal of Power Electronics
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• v.16 no.6
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• pp.2182-2191
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• 2016

This study proposes a novel frame anti-vibration controller for position sensorless PMSM drive application. This controller is called specific component reduction controller (SCRC). SCRC can function without an accelerometer and can achieve speed variable control. This study mainly comprises the following phases. First, the position sensorless control method will be provided. Second, the frame vibration model and load torque ripple will be shown. Third, SCRC will be discussed and its stability will be analyzed. Finally, experimental results show that SCRC can achieve speed variable anti-vibration control and compensate target frequency torque ripple.

• Journal of Wind Energy
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• v.2 no.2
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• pp.54-60
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• 2011

A PMSG in variable speed wind turbine needs to know the position of rotor for vector control. Since the position sensor has the disadvantage in terms of cost, complexity of the system, a sensorless algorithm is needed. The sensorless strategy using the back EMF estimation is used for PMSG Wind Turbine. This algorithm is comparatively easy to implement than other strategies. This paper introduces the application of stable sensorless control for 2MW direct drive PMSG. In order to confirm the sensorless algorithm, the implementation is proceeded using 2MW direct drive PMSG from no-load condition to full-load condition. To drive 2MW PMSG artificially, 2MW PMSG connected PMSG through the mechanical coupling.

• Journal of Power Electronics
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• v.10 no.5
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• pp.485-490
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• 2010

Sensorless control methods are generally used in motor control for home-appliances because of the material cost and manufactureing standard restrictions. The current model-based control algorithm is mainly used for PMSM sensorless control in the home-appliance industry. In this control method, the rotor position is estimated by using the d-axis and q-axis current errors between the real system and a motor model of the position estimator. As a result, the accuracy of the motor model parameters are critical in this control method. A mismatch of the PMSM parameters affects the speed and torque in low speed, steadystate responses. Rotor position errors are mainly caused by a mismatch of the stator resistance. In this paper, a stator resistance compensation algorithm is proposed to improve sensorless control performance. This algorithm is easy to implement and does not require a modification of the motor model or any special interruptions of the controller. The effectiveness of the proposed algorithm is verified through experimental results.

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.660-662
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• 2004

This paper proposes an Intelligent Speed Estimator in order to realize the speed-sensorless vector control of an induction motor. Intelligent Speed Estimator used Model Reference Adaptive System which has Fuzzy-Neural adaptive mechanism as Speed Estimation method. The Intelligent Speed Estimator estimates the speed of an induction motor with a rotor flux of a reference model and adjustable model in MRAS. The Intelligent Speed Estimator reduces the error of the rotor flux between the voltage flux model and the current flux model using the error and the change of error as input of the Estimator. The computer simulation is executed to verify the propriety and the effectiveness of the proposed speed estimator.