• Proceedings of the KIEE Conference
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• 1998.07a
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• pp.9-11
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• 1998

Most of sensorless algorithms are based on motor equations including electrical and mechanical parameters. However, parameter variation and uncertain error decrease the accuracy of speed estimation of PMSM. This paper investigates the sensorless speed control of PMSM considering parameter variation. The proposed algorithm use the speed compensator which is robust in parameter variation and error. The simulation and experimental results indicate good performances.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1997.10a
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• pp.426-431
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• 1997

In this paper, a sensorless realization method is proposed for the magnetic levitation system. Also we design the robust servo controller which based on the two degree-of-freedom-control theory and H$\sub$.inf./ control theory for the system. From time responses, we confirm that the proposed sensorless method can be applied the magnetic levitation system. Also the designed controller has the good disturbance rejection and the reference tracking performance.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.60 no.4
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• pp.227-235
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• 2011

This paper describes a PMSM control algorithm for realizing a low-cost motor drive system using a general purpose microcontroller. The proposed sensorless algorithm consists of the current observer and the sensorless scheme based on instantaneous reactive power. Also the control board system is not the high-cost DSP(digital signal processor) system but the general purpose microcontroller and it allows to reduce the unit cost of the motor system. However the clock frequency of the proposed microcontroller is one-fifths for the clock frequency of the DSP. In addition, the switching frequency must be selected as the lower frequency because of complex mathematic modeling of the sensorless algorithm. the low switching frequency augments the noise of the motor and might make accurate speed control impossible. Thus this paper proposes the optimization method to supplement the drawback of the general purpose microcontroller and the usefulness of the proposed method is verified through the experiment.

• Proceedings of the KIPE Conference
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• 2007.11a
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• pp.7-10
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• 2007

The current model based sensorless method has many benefits that it can be robust control for large load torque. However, this method should determine a coefficient of back electro motive force(back-emf). This coefficient is varied by load torque and speed. Also, the coefficient determining equation is not exist, so it is determined only by experiment. On the other hands, using only back-emf estimatior method can not drive in low speed area and it has weakness in load variation. For these problems, this paper suggests the hybrid sensorless method that mixes the back-emf estimator regarding saliency and the current based sensorless model. This estimator offers not only non-necessary coefficient for current sensorless model, but also wide speed area operating in no specific transition method.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.10
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• pp.1858-1864
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• 2011

This paper suggests a control technique of the sensorless brushless DC (BLDC) motor drive for a vehicle fuel pump application. The sensorless technique based on a comparator and a potential start-up method with high starting torque are proposed. The comparator is used to generate the commutation signals in phase with the three-phase back-EMFs. The rotor position is aligned at standstill for maximum starting torque without an additional sensor and any information of motor parameters. Also, the stator current can be easily adjusted by modulating the pulse width of the switching devices during alignment. Some experiments are implemented on a single chip 16-bit DSP controller to demonstrate the feasibility of the sensorless techniques.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.12
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• pp.82-87
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• 2011

In this paper, a sensorless speed control system is designed for the next generation high speed railway at zero and low speed region. The applied vector control scheme is a maximum torque per ampere(MTPA) method to utilize reluctance torque of IPMSM. The designed sensorless control scheme is a rotating high frequency voltage signal injection method. To verify the designed system, a simulator for the vector controller and sensorless controller is implemented using Matlab/simulink.

• Proceedings of the KIPE Conference
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• 2008.06a
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• pp.115-117
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• 2008

Generally, because of the cost and the restricted manufacture standard, the motor control for home appliance have been used the method using hall sensors or the sensorless method. In the conventional sensorless method using home appliance, the resistor and the back-EMF coefficient are varied by the motor speed and the load torque. Therefore, these variations cause the position error when the sensorless control is operated. This paper proposes the compensation method for sensorless position error using 2-hall sensor pulse signals.

• Proceedings of the KIEE Conference
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• 2001.07b
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• pp.983-985
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• 2001

Sensorless induction motor drive is much studied due to the cost and reliability of speed and position sensors. Most sensorless algorithms are based on the mathematical modeling of induction motor including electrical variables such as phase current and voltage. Therefore, the accuracy of such variables largely affects the performance of sensorless induction motor drive. However, the phase voltage does not have to be directly monitored because of switching noise, and they may be reconstructed by using the command voltage. The output voltage of SVPWM-VSI supplying the motor has a considerable error, especially in a low speed range because SVPWM-VSI has a poor resolution in a low command voltage. Such a voltage information effect in speed sensorless control of induction motor has been investigated in this paper.

• Proceedings of the KIPE Conference
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• 2003.11a
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• pp.119-122
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• 2003

This paper describes the sensorless technique for the surface-mounted permanent-magent synchronous motor(SPMSM or PMSM) drive based on magnetic saliency. The control technique is a sensorless control algorithm that injects the high frequency voltage to the stator terminal in order to estimate the rotor position and speed. The rotor position and speed for sensorless vector control is achieved by appropriate signal processing to extract the position information from the stator current in the low speed range including zero speed. Proposed sensorless algorithm using the double-band hysteresis controller and initial rotor position detection exhibits excellent reference tracking and increased robustness. Experimental results are presented to verify the feasibility of the proposed control schemes.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.55 no.2
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• pp.61-68
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• 2006

Many researchers have worked for the sensorless control of SynRM in recent years. However they commonly requires large calculations which induced from its complexity. For low cost application as like home appliance, it is difficult to utilize because of the cost problem. Therefore, it is necessary to introduce simplified sensorless control scheme that is composed of least calculation to estimate the rotor position. In this paper the sensorless control is performed using the characteristics of SynRM structure in which the linkage flux varies with rotor position, so the rotor position can be detected by the change of linkage flux. The estimation of linkage flux can be acquired from the integration of the motor terminal voltage which is commonly used method for the reliability of the estimation. However this estimation method has demerits in low speed operation therefore in that region the motor terminal voltage is compensated by the phase current. A digital simulation (MATLAB) and experiment were performed to confirm the adequacy of the proposed control scheme.