• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.494_495
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• 2009

This paper presents a study of DFIG wind power generation system for real-time simulation. For real-time simulation, the real-time digital simulator (RTDS) and its user friendly interface simulation software (RSCAD) are used. 2.2MW grid-connected variable speed DFIG wind power generation system is modeled and analyzed in this study. Stator-flux oriented vector control scheme is applied to stator, rotor side converter control, and back-to-back PWM converters are implemented for the decoupled control. The real-wind speed signal extracted by an anemometer is used for realistic and accurate simulation analysis. Block diagrams for DFIG and control scheme of stator, rotor-side are introduced. Real-time simulation cases are carried out and analyzed for the validity of this work.

• 전기전자학회논문지
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• 제28권3호
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• pp.426-431
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• 2024

본 논문은 특성 전류의 크기를 반영한 PMSM(Permanent Magnet Synchronous Motor) 드라이브의 약계자 제어 알고리즘을 제시한다. 변화한 영구자석 쇄교 자석의 비율을 계산하기 위해 고정자 쇄교 자속 관측기를 활용하였다. 계산된 영구자석 쇄교 자속의 비율로 특성 전류의 크기가 간접적으로 계산된다. 계산된 영구자석 쇄교 자속은 3D Look-up talbe(LUT)를 통해 IPMSM(Interior Permanent Magnet Synchronous Motor)의 MTPV(Maximum Torque Per Voltage)제어 사용 여부를 결정한다. 제안된 약계자 제어 방식은 시뮬레이션을 통해 검증된다.

• Journal of Power Electronics
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• 제9권6호
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• pp.911-918
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• 2009

This paper presents a new sensorless control method for single-phase switched reluctance motors using induced electromotive force (EMF) due to the residual flux both on the stator and the rotor during phase commutation. The induced EMF falls to zero when the rotor pole moves away from the overlap with the stator pole. By detecting this instant, the speed and position of the rotor can be simply estimated. This method is very simple to implement and it is insensitive to variations in the system parameters as it does not require any stored magnetic data or offline inductance measurements but requires only measurements of the terminal voltage and a simple analog circuit. The proposed method is implemented on a 6/6 single-phase switched reluctance motor. However, it can also be implemented on a multiphase SRM regardless of the size, operation speed and switching mode of the motor hence making the proposed method viable to many applications. Simulation and experimental verification is provided to demonstrate the feasibility of the proposed method.

• Journal of international Conference on Electrical Machines and Systems
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• 제1권1호
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• pp.47-53
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• 2012

A novel 6/5 switched reluctance motor (SRM) with short flux path is presented in this paper. The concept of this proposed motor is a novel SR motor with six stator and five rotor poles. The stator is constructed with three independent and physically separate C-core segments, and the rotor is composed of five poles. This motor, with a new selection for the number of stator/rotor poles, achieves a short flux path, which reduces the magnetomotive force required to drive the motor. To verify the performance of the proposed motor, a comparison with conventional SR motors with the same dimensions is executed. The comparison demonstrates that the proposed motor offers better performance in terms of maximum torque production. Furthermore, Finite Element Analysis (FEA) and Matlab/Simulink software are used to predict and simulate the performance of the proposed motor.

• Journal of Power Electronics
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• 제11권6호
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• pp.864-869
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• 2011

This paper presents a sensorless control and parameter estimation strategies for a Transverse Flux Rotating Motor (TFRM). The proposed sensorless control method is based on a Model Reference Adaptive System (MRAS) to estimate the stator flux. Parameter estimation theory is also applied into the sensorless control method to estimate motor parameters, such as inductances. The effectiveness of the proposed methods is verified by some simulations and experiments.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 D
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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.

• Journal of Power Electronics
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• 제14권1호
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• pp.125-134
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• 2014

This paper presents a robust and speed-sensorless stator flux estimation for induction motor direct torque control. The proposed observer is based on sliding mode approach. Stator electrical equations are used in the rotor orientation reference frame to eliminate the observer dependence on rotor speed. Lyapunov's concept for systems stability is adopted to confine the observer gain. Furthermore, the sensitivity of the observer to parameter mismatch is recovered with an adaptation technique. The nonlinearities of the pulse width modulation voltage source inverter are estimated and compensated to enhance stability at low speeds. Therefore, a new method based on the model reference adaptive system is proposed. Simulation and experimental results are shown to verify the feasibility and effectiveness of the proposed algorithms.

• Journal of Power Electronics
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• 제9권3호
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• pp.438-446
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• 2009

The performance of direct torque controlled (DTC) interior permanent magnet (IPM) machines is poor at low speeds due to a few reasons, namely limited accuracy of stator voltage acquisition and the presence of offset and drift components in the acquired signals. Due to factors such as forward voltage drop across switching devices in the three phase inverter and dead-time of the devices, the voltage across the machine terminals differ from the reference voltage vector used to estimate stator flux and electromagnetic torque. This can lead to instability of the IPM drive during low speed operation. Compensation schemes for forward voltage drops and dead-time are proposed and implemented in real-time control, resulting in improved performance of the space vector modulated DTC IPM drive, especially at low speeds. No additional hardware is required for these compensators.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2001년도 전력전자학술대회 논문집
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• pp.276-279
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• 2001

Direct torque control(DTC) is known to produce quick response in ac drives. Some drawbacks of the classical DTC are the relatively large torque ripple in a low speed range and notable current pulsation during steady state. They are reflected speed response and increased acoustical noise. In this paper, The DTC quick response are preserved at transient state, while better qualify steady state performance is produced by Space Vector Modulation(SVM). It is able to reduce the acoustical noise, torque ripple and current pulsation during steady state. The system presented are closed loop stator flux and torque observer for wide speed range that inputs are currents and voltages sensing of motor terminal. Simulation results for the 2.2kw general purposed induction motor are presented and discussed.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2000년도 추계학술대회 논문집
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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.