• The Transactions of the Korean Institute of Power Electronics
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• v.18 no.3
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• pp.225-231
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• 2013

This paper presents an improved signal processing technique in the square-wave-type voltage injection method for IPMSM sensorless drives. Since the sensorless method based on the square-wave voltage injection does not use low-pass filters to get an error signal for estimating rotor position and allows the frequency of the injected voltage signal to be high, the sensorless drive system may achieve an enhanced control bandwidth and reduced acoustic noise. However, this sensorless method still requires low-pass and band-pass filters to extract the fundamental component current and the injected frequency component current from the motor current, respectively. In this paper, these filters are replaced by simple arithmetic operations so that the time delay for estimating the rotor position can be effectively reduced to only one current sampling. Hence, the proposed technique can simplify its whole signal process for the IPMSM sensorless control using the square-wave-type voltage injection. The proposed technique is verified by the experiment on the 800W IPMSM drive system.

• 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 KIPE Conference
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• 2001.12a
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• pp.115-118
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• 2001

This paper presents a new sensorless control scheme using simple duty signal feedback technique in DC-DC converters. The proposed sensorless control scheme (DFC) has the characteristics that they show the same as operation performance of current mode control by using duty feedback technique without current sensor as well as present better dynamic response performance than conventional sensorless current mode control (SCM) in case that input source is perturbed by step change or DC input source includes the . harmonics. Also, the proposed control scheme has good noise immunity and simple control circuits since they have one feedback loop, and can be applied to all DC-DC converters. The concept and control principles of the proposed control scheme are explained in detail and the validity of the proposed control scheme is verified through several interesting simulated results.

• Journal of Power Electronics
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• v.15 no.6
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• pp.1559-1566
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• 2015

The brushless DC motor (BLDCM) has many advantages. As a result, it is widely used in electric vehicle (EV) drive systems. To improve the reliability of the motor control system, a position sensorless control strategy based on a sliding mode observer (SMO) is proposed. The global fast terminal sliding mode observer (GFTSMO) is proposed to enhance the control performance of the SMO control system. The advantages of the linear sliding mode and the nonsingular terminal sliding mode (NTSM) are combined in the control strategy. The convergence speed of the system state is enhanced. The motor commutation point is obtained with the observation of the back EMF, and the instantaneous torque value of the motor is calculated. Therefore, the position sensorless control of the BLDCM is realized. Experimental results show that the proposed control strategy can improve the convergence speed, dynamic characteristics and robustness of the system.

• The Transactions of the Korean Institute of Power Electronics
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• v.17 no.3
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• pp.238-245
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• 2012

This paper presents a sensorless speed control of a 2-phase switch reluctance motor(SRM). The proposed sensorless control scheme is based on the slide mode observer with parameter compensator to improve the estimation performance. In the stand still position, the initial rotor position is determined by pulse current responses of each phase windings and the current difference. In order to determine an accurate initial rotor position, the two initial rotor positions are estimated by the difference of the pulse currents. From the stand still to the operating region, a simple open loop control which determines the commutation sequence by the pulse current of the unexcited phase winding is used. When the motor speed is reached to the sensorless control region, the estimated rotor position and speed by the slide mode observer are used to control the SRM. The flux calculator used in the slide mode observer is designed by phase voltage and the voltage drops in the phase resistance of the winding. The accuracy of the flux calculator is dependent on the phase resistance. For the continuous update of the phase resistance, current gradient at the inductance break point is used in this paper. The error of the estimated rotor position at the current gradient position is used to update the phase resistance to improve the sensorless scheme. The proposed sensorless speed control scheme is verified with a practical compressor used in home appliances. And the results show the effectiveness of the proposed control scheme.

• The Transactions of the Korean Institute of Power Electronics
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• v.20 no.3
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• pp.232-238
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• 2015

A sensorless control algorithm of brushless DC (BLDC) motors with a model current based on 120 degree conduction mode is proposed in this paper. The rotor speed and position can be estimated using the current model of BLDC motor, which is a modified version of the conventional current model of permanent magnet synchronous motor. The rotor speed and position can be obtained using the difference of the actual current and the model current. The position error caused by the parameter errors of the model current is compensated using a PI controller and the feedback loop of the real current. The validity of the proposed sensorless control algorithm is verified through simulation.

• Journal of Electrical Engineering and Technology
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• v.9 no.3
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• pp.873-881
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• 2014

Speed sensorless modes of operation are becoming standard solution in the area of electric drives. This paper presents flux estimator and speed estimator for the speed sensorless vector control of induction motors. The proposed sensorless methods are based on the model reference adaptive system (MRAS) observer and adaptive speed observer (ASO). The proposed speed estimation algorithm can be employed in the power control of grid connected induction generator for wind power applications. Two proposed schemes are verified through computer simulation PSIM and compared their simulation results.

• Proceedings of the KIPE Conference
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• 2015.07a
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• pp.507-509
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• 2015

In this paper, a novel method of sensorless control scheme is proposed to apply on a single phase hybrid SRM used in high speed operation. The proposed method utilizes beneficially permanent magnet field whose performance is motor parameter independent to estimate the rotor position. Also, the current slope is adopted to complete the sensorless control when the motor running with heavy torque at high speed condition. Through this approach, the adjustable turn on/off position can be achieved without prior knowledge of inductance profile which is always employed by many sensorless schemes. And this paper may offer an available method to do the sensorless control in hybrid SRM used for high speed running.

• Proceedings of the KIEE Conference
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• 2001.10a
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• pp.161-164
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• 2001

This paper presents a digital speed sensorless control system for Reluctance Synchronous Motor (RSM) drives with direct torque control (DTC). The system consist of stator flux observer, rotor speed estimator, torque estimator two hysteresis band controllers, an optimal switching look-up table. IGBT voltage source inverter, and TMS320C31DSP controller by using fully integrated control software. The stator flux observer is based on the combined voltage and current model with stator flux feedback adaptive control that inputs are current and voltage sensing of motor terminal with estimated rotor angle for wide speed range. The rotor speed is estimated by the observed stator flux-linkage space vector. The estimated rotor speed can be determinated by differentiation of the rotor position used only in the current model part of the flux observer for a low speed operating area. In order to prove the suggested speed sensorless control algorithm. There are some simulation and testing at actual experimental system. The developed digitally high- performance speed sensorless control system are shown a good speed control response characteristic results and high Performance features using 1.0Kw RSM.

• Proceedings of the KIPE Conference
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• 2001.07a
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• pp.397-400
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• 2001

This paper presents a implementation of digital sensorless position control system of surface permanent-magnet synchronous motor (SPMSM) drive with a direct torque control (DTC). The system are stator flux and torque observer of stator flux feedback control model that inputs are current and voltage sensing of motor terminal with estimated rotor angle for a low speed operating area, two hysteresis band controllers, an optimal switching look-up table, rotor speed estimator, and IGBT voltage source inverter by using fully integrated control software. The developed sensorless control system are shown a good motion control response characteristic results and high performance features using 1.0 (kW) purposed servo drive SPMSM.