• Proceedings of the KIPE Conference
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• 2000.07a
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• pp.600-604
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• 2000

In this paper authors proposed a new nonlinear rotor flux observer for rotor field oriented control of an induction motor which is designed based on theory of the extended Luenberger observer(ELO) one of a nonlinear state observer. The proposed rotor flux observer is derived from the 2 phase model of induction motor by the theory of ELO. The simulation results taken under the varying condition of rotor resistance and load torque show fast convergence of estimated rotor flux and high performance of IM drive system is achieved 표 experiment.

• 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.

• Journal of Electrical Engineering and Technology
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• v.13 no.2
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• pp.829-837
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• 2018

In this paper, a flux linkage model based on four magnetization curves fitting is proposed for three-phase 12/8 switched reluctance motor (SRM), with the analysis of the basic principle of flux detection method and function analysis method. In the model, the single value function mapping relationship between position angle and flux is established, which can achieve a direct estimation of rotor position. The realization scheme of SRM indirect position detection system is presented. It is proved by simulation and experiment that the proposed scheme is suitable for rotor position detection of SRM, and has high accuracy of position estimation.

• Proceedings of the KIEE Conference
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• 1989.11a
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• pp.268-272
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• 1989

To avoid the use of position sensor or flux sensor in a field oriented induction machine drive system, the terminal quantities are often used to estimate the rotor flux. Since the estimation involves the leakage inductance of the machine, the performance of such systems is sensitive to the variations of leakage. Since estimation of the stator flux is independent of the leakage, the steady state performance of the stator flux oriented system is insensitive to the leakage inductance. In this paper, the torque response of stator flux oriented system is compared to that of rotor flux oriented system by digital simulation. And induction motor sensor less speed control by stator flux oriented method is developed. The performance of the speed estimation is showed by digital simulation.

• Proceedings of the KSR Conference
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• 2000.11a
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• pp.680-687
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• 2000

In this paper we present a new vector control scheme for induction motor. An exact knowledge of the rotor flux position is essential for a high-performance vector control. The position of the rotor flux is measured in the direct scheme or estimated in the indirect schemes. Since the estimation of the flux position requires a priori knowledge of the induction motor parameters, the indirect schemes are machine parameter dependent. The rotor resistance and stator resistance among the parameters change with temperature. Variations in the parameters of induction machine cause deterioration of both the steady state and dynamic operation of the induction motor drive. Several methods have been presented to minimize the consequences of parameter sensitivity in indirect scheme. In this paper new estimation scheme of rotor flux position is presented to eliminate sensitivity due to resistance change with temperature. Simulation results are used to verify the performance of the proposed vector control scheme.

• Proceedings of the KIEE Conference
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• 2001.07d
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• pp.2246-2248
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• 2001

This paper presents a new vector control scheme for induction motor. An exact knowledge of the rotor flux position is essential for a high-performance vector control. The position of the rotor flux is measured in the direct schemes and estimated in the indirect schemes. Since the estimation of the flux position requires a priori knowledge of the induction motor parameters, the indirect schemes are machine parameter dependent. The rotor and stator resistance among the parameters change with temperature. Variations in the parameters of induction machine cause deterioration of both the steady state and dynamic operation of the induction motor drive. Several methods have presented to minimize the consequences of parameter sensitivity in indirect scheme. In this paper, new estimation scheme of rotor flux position is presented to eliminate sensitivity due to variation in the resistance. The simulation is executed to verify the proposed vector control performance and to compare its performance with that of indirect and direct vector control.

• Proceedings of the KIEE Conference
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• 1997.07f
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• pp.2088-2090
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• 1997

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. The proposed adaptive algorithm for rotor resistance estimation in the synchronous reference frame is applied by sliding mode current controller satisfing persistent excitation(PE) condition. Adaptive flux observer is here used for the purpose of estimating rotor flux and speed in the speed sensorless scheme. Computer simulations are carried out to verify the validity of the proposed algorithm.

• The Transactions of the Korean Institute of Power Electronics
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• v.9 no.5
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• pp.413-419
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• 2004

In the induction motor direct vector control system using the Gopinath model flux observer, the deterioration of the dynamic response due to the detuned rotor time constant is investigated. To solve this problem, the on line estimation algorithm of the rotor time constant using model reference adaptive control is proposed. The effect of the motor parameter variation on the rotor time constant estimation is analyzed through experiment. The estimation error due to the parameter variation converges within 5%. Thus applying the proposed algorithm to the Gopinath model flux observer, the robust direct vector control system of the induction motor to the parameter variation can be implemented.

• Proceedings of the KIPE Conference
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• 1999.07a
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• pp.505-508
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• 1999

Conventional adaptive speed estimators cannot avoid the influence of the non-linear inductance variation under the saturation conditions. Without speed sensors, it is difficult to identify the inductance variation using a reactive power mode because the model contains a term of the rotor speed. In this paper, we propose a novel speed estimator having hybrid architecture in order to estimate both the rotor speed and the inductance variation simultaneously when the motor flux is saturated. Proposed estimator consists of the error between the flux obtained from the stator voltage equation and the flux estimated from the rotor flux observer. Introducing a new correction term into the estimator increases the estimation ability of the conventional speed estimator even though the motor flux is saturated. The convergence of the speed estimation error is examined by simulation Furthermore, the experimental results show the validity of the proposed method.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.52 no.10
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• pp.522-527
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• 2003

This paper proposes a new speed and flux estimation method which has the robustness against the variation of the electrical parameters of the motor and the superiority in the dynamic characteristics. In the proposed method, the stator currents and the rotor fluxes are observed on the stationary reference frame using the sliding mode concept. And the rotor speed is estimated using the current estimation errors and the observed rotor fluxes based on the Lyapunov stability theory. Also a design method of the observer gain is proposed to minimize the effect of the speed estimation error on the rotor flux observation. The experimental results are shown to verify that the proposed method shows the excellent performances under the variations of motor resistance and inductance.