• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.05b
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• pp.71-74
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• 2003

The paper is proposed to position and speed control of interior permanent magnet synchronous motor(IPMSM) drive without mechanical sensor. A minimum order state observer is used for the mechanical state estimation of the motor. The observer was developed based on nonlinear model of IPMSM, that employs a d-q rotating reference frame attached to the rotor. A minimum order state observer is implemented to compute the speed and position feedback signal. The validity of the proposed sensorless scheme is confirmed by various response characteristics.

• Journal of Power System Engineering
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• v.1 no.1
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• pp.144-153
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• 1997

The magnetic levitation system is utilized in the magnetic bearing of high-speed rotor because of little friction, no lubrication, no noise and so on. The magnetic levitation system need the feedback controller for the stabilization of system, and gap sensors are generally used to measure the gap. The use of gap sensors brings out the increase of the number of troublesome, and the decrease of the control performance because of the dislocation between the measurement point and the control point. This paper presents the design of the gap estimation circuit for the sensorless method proposed by authors in the magnetic levitation system. We made the gap estimation circuit which was composed of both the superposition circuit and the measuring circuit. And we investigated the validity of the usefulness of the proposed sensorless method in the magnetic levitation system through results of actual experiment.

• Journal of Power Electronics
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• v.2 no.2
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• pp.146-153
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• 2002

this paper presents an implementation of digital control system of speed sensorless for Reluctance Synchronous Motor (RSM) drives with direct torque control (DTC). The problem of DTC for high-dynamic performance RSM drive is generating a nonlinear torque due to a saturated nonlinear inductance curve with various load currents. The control system consists of stator flux observer, compensating inductance look-up table, rotor position/speed/torque estimator, two hysteresis band controllers, an optimal switching look-up table, IGBT voltage source unverter, and TMS320C31 DSP controller. The stator flux observer is based on the combined voltage and current model with stator flux feedback adapitve control that inputs are the compensated inductances, current and voltage sensing of motor terminal with estimated rotor angle for wide speed range. The rotor position is estimated rotor speed is determined by differentiation of the rotor position used only in the current model part of the flux observer for a low speed operation area. It does not requrie the knowledge of any montor paramenters, nor particular care for moter starting, In order to prove the suggested control algorithm, we have simulation and testing at actual experimental system. The developed sensorless control system is showing a good speed control response characterisitic result and high performance features in 20/1500 rpm with 1.0Kw RSM having 2.57 ratio of d/q reluctance.

• Journal of Advanced Marine Engineering and Technology
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• v.22 no.3
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• pp.311-319
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• 1998

DC Motors have been widely used in industry as driving power motors for electrical vehicles cranes and winches due to their strong starting torques and as servo-motors for position and speed control systems due to their convenience of speed control etc. Generally in the speed control systems of motors speed sensors are required and this fact results in he increased price and operating cost and in the limitted applications. This paper presents a new speed control method for sensorless DC motors. In this scheme the speed signal is estimatd by the measurement values of the armature voltage and current. A Fuzzy feedback controller instead of the conventional PID controller. Through simulations the effectiveness and usefullness of the proposed method are illustrated.

• Proceedings of the KIPE Conference
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• 1998.10a
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• pp.736-741
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• 1998

It is well known that an encoder or a resolver is necessary to obtain the position data for speed or position control Generally utilized speed sensors are mal-affected by the EMI, dusty, and high temperature surroundings. Therefore, the speed and position sensorless controls using observers have been studied widely. In this paper, the binary observer which is composed of two feedback regulation loops to control the speed of SRM(Switched Reluctance Motor) is applied. One loop compensates the control input directly like the sliding mode control, and the other one compensates the system parameters indirectly. This observer is constructed on the foundation of variable structure control on the foundation of variable structure control theory and has the inertial term for the varying parameter. The validities of this proposed method is proved by experiments.

• Journal of Electrical Engineering and Technology
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• v.2 no.2
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• pp.280-285
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• 2007

This paper presents a robustly adaptive flux observer for speed-sensorless induction motor control. The proposed approach employs additional robustifying signals to cope with the parametric uncertainties instead of designing an estimator, which has been normally used in power electronic drives. For that, the sliding-mode like adaptive controls are designed and their gain parameters are determined so that the observer dynamics are stable in the sense of Lyapunov, and furthermore they can guarantee the robustness against parametric uncertainties in induction motor systems. Estimated rotor speed is to be used to generate feedback control signal for the speed sensorless vector control system. To show the validity and efficiency of the proposed system, simulation results are presented.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2000.10a
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• pp.562-567
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• 2000

This paper proposed a speed estimator using MRAC(Model Reference Adaptive Control) for sensorless vector control. It is robust for parameter variation and the estimated speed is used as feedback in a vector control system. Computer simulation is presented to confirm the theoretical analysis.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.55 no.2
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• pp.98-106
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• 2006

This paper proposes to position and speed control of interior Permanent magnet synchronous motor(IPMSM) drive without mechanical sensor. Also, this paper develops a adaptive fuzzy controller based fuzzy logic control for high performance of PMSM drives. In the proposed system, fuzzy control is used to implement the direct controller as well as the adaptation mechanism. A Gopinath observer is used for the mechanical state estimation of the motor. The observer was developed based on nonlinear model of IPMSM, that employs a d-q rotating reference frame attached to the rotor. A Gopinath observer is implemented to compute the speed and position feedback signal. The validity of the proposed scheme is confirmed by various response characteristics.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.5B no.4
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• pp.358-365
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• 2005

In induction machine drive without a speed sensor, the estimation of the motor flux and speed often becomes deteriorated at low speeds with low back EMF. Our analysis shows that, in addition to the state resistance variation, the estimated value of field orientation angle is often corrupted by accumulative errors from the integration of voltage variables at motor terminals that have low signal/noise ratio at low frequencies. A repetitive loop path of integration in the feedback can amplify this type of error, thus speeding up the degradation process. The control system runs into information starvation due to the loss of correct field orientation. The machine's spiral vectors are controlled only in a reduced dimension in this situation. A novel control scheme is developed to improve the control performance of motor's current, torque and speed at low frequencies. The scheme gains a full-dimensional vector control and is less sensitive to the combined effect of the error sources at the low frequencies. Experimental tests demonstrate promising performances are achievable even below 0.5 Hz.

• Proceedings of the KIEE Conference
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• 2003.07d
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• pp.2203-2205
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• 2003

In this thesis, it is a purpose to carry out speed control of DC servo motor without using encoder and the resolver which are speed sensor of DC servo motor and it should use estimate algorithm or observer and must assume a speed in order to control speed sensorless. Therefore, high gain observer was designed to estimate rotor speed of DC servo motor and it carries out speed control from the feedback of the speed that assumed done in the thesis. Also, implementation used easy PI controller in speed-controller of DC motor though it was simple. It is compared estimate performance of Luenberger and high gain observer in a way of computer simulation in order to verify performance of the high gain observer which proposed in this thesis, and proved excellency of the high gain observer. And the thesis proved that smooth speed sensorless control of DC servo motor was implemented in invariable driving.