• The Transactions of the Korean Institute of Power Electronics
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• v.4 no.2
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• pp.209-214
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• 1999

New estimation and tuning schemes of inductance variations for rotor flux oriented (RFO) control of induction motor in field weakening region are presented. Stator transient inductance and stator self inductance are estimated. From estimated stator self inductance. magnetizing inductance is estimated and from estimated stator transient inductance, rotor leakage inductance is estimated. Simulation and experimental results prove the effectiveness of the proposed s scheme in constant torque and field weakening region.

• Proceedings of the KIEE Conference
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• 1994.07a
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• pp.277-279
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• 1994

In this paper, a novel field weakening scheme for the induction machine by the voltage control strategy is presented. The proposed algorithm ensures producing the maximum torque over the entire field weakening legion. Also by introducing the direct field-oriented control in the field weakening legion with large variation in machine parameters, the drive system can obtain the robustness to machine parameter variation. Moreover, by using estimated speed, sensorless speed control can be possible in very high speed lesion. Experimental results for a laboratory induction motor drive system confirm the validity or the proposed control algorithm.

• Journal of the Korean Society of Safety
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• v.17 no.2
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• pp.32-38
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• 2002

In this paper, a new approach for the SynRM(Synchronous Reluctance Motor) control which ensures producing MTPA(Maximum Torque per Ampere) over the entire field weakening region is presented. In addition, this paper presents a speed sensorless control scheme of SynRM using flux observer. Also, by adjusting the base speed for the field weakening operation according to the flux level, the current and voltage limit, the smooth and precise transition into the field weakening operation can be achieved. The validity of the proposed scheme is verified through simulation.

• Proceedings of the KIPE Conference
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• 2004.07a
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• pp.269-273
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• 2004

It is important to estimate the rotor speed for field weakening operation in the speed sensorless stator flux oriented (SFO) induction motor drive. Several methods have been reported to estimate exactly the speed in the speed sensorless system. In this paper, we apply two observer-based methods, the Luenberger observer (LO) and the Kalman filter (KF), to SFO induction motor drive in order to achieve a speed sensorless operation in field weakening region. Two control methods are reviewed and discussed. The operation characteristics of these methods in the field weakening region is compared by simulation and experiment.

• Proceedings of the KIPE Conference
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• 1999.07a
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• pp.26-30
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• 1999

The constraint condition is the stator voltage and the stator current to operate the motor in the flux weakening region. The maximum current is limited by the inverter current rating and the machine thermal rating. Given DC link voltage to control the motor in the flux weakening the maximum voltage is determined by considering PWM strategy, dead time, voltage drop of the inverter switching device, and the margin of the voltage for current forcing. In this paper, the new method to determine the available maximum voltage is derived by the analythic method and by considering the factors of the voltage drop. So Determining the maximum voltage is very useful to enlarge the speed operation region in the flux weakening operation, the utility of the maximum voltage is increased.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.881-882
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• 2008

For the interior permanent magnet synchronous motor(IPMSM) drive to operate above the base speed in the constant horsepower region, the field weakening control is applied. However, the field weakening control was not almost applied to sensorless control of the interior permanent magnet synchronous motor. In this paper, the field weakening control is applied to the sensorless control of IPMSM based on the fuzzy controller. The effectiveness of the proposed system is verified by the experimental results.

• Proceedings of the KIPE Conference
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• 2006.06a
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• pp.95-97
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• 2006

This paper investigates the field weakening operation of a five-phase IPMSM(inner permanent magnet synchronous motor). The five-phase motor can supply sinusoidal voltage and third harmonic voltage because of more freedom of control. This paper present field weakening algorithm and experimental results for five-phase IPMSM which has trapzoidal back-EMF and concentrate winding to prove the validity of the proposed algorithm.

• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.923-924
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• 2006

For the interior permanent magnet synchronous motor(IPMSM) drive to operate above the base speed in the constant horsepower region, field weakening control is applied. However, the field weakening control was not almost applied to sensorless control of the interior permanent magnet synchronous motor. In this parer, field weakening control is applied to the sensorless control of IPMSM based on an instantaneos reactive power. The effectiveness of the Proposed system is verified by the experimental results.

• Proceedings of the KIPE Conference
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• 2004.11a
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• pp.27-31
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• 2004

This paper presents a nonconventional method for oft starting of three-phase induction motors, which achieved by flux weakening technique. flux weakening is not done by reducing the applied voltage as in the conventional methods, Flus weakening is achieved y increasing the supply frequency over the rated value while the voltage amplitude is kept constant. This method has advantage of reducing the stress on the electrical and mechanical systems. The feasibility of this basic idea has been confirmed through investigating the starting transient corresponding to this mode of operation. For this purpose, a rigorous state space mathematical model has been developed and simulated. The validity of the proposed method through the results from the mathematical model have been confirmed experimentally.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.50 no.10
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• pp.508-512
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• 2001

This paper investigates the problem of the speed estimation of conventional speed sensorless stator flux-oriented induction machine drive in the field weakening region and proposes a new speed estimation scheme to estimate speed exactly in transients in the field weakening region. The error included in the estimated rotor speed is removed by not a low pass filter but Kalman filter so that exact speed estimation in transients is achieved.