• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1998년도 하계종합학술대회논문집
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• pp.955-957
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• 1998

Switched reluctance motor(SRM) has the advantages of simple structure, low rotor inertia, and high poer rate per unit volume. However, position sensor isessential in SRM in order to synchronize the phase excitation to the rotor position. The position sensors increase the cost of drive system, and tend to reduce system reliability. This paper investigtes the speed control of sensorless SRM. The proposed system consists of position detection circuit, dwell angle controller, digital logic commutator, PI speed controller and 4-phase inverter. The performances in the proposed system are verified through the experiment.

• 전력전자학회논문지
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• 제9권3호
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• pp.246-252
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• 2004

본 논문에서는 신경회로망을 이용한 위치센서 없는 스위치드 릴럭턴스 전동기의 제어시스템에 관해 연구하였다. 스위치드 릴럭턴스 전동기는 회전자 위치에 따라 적정 고정자 권선을 여자시킴으로써 회전력을 발생하기 때문에 회전자 위치정보가 필수적이다. 회전자 위치추정을 위한 위치 검출기는 전반적인 시스템 비용을 증가시키고, 시스템이 복잡해지는 요인이 된다. 본 논문에서는 전류와 자속에 대한 회전자 위치정보의 룩업 테이블을 바탕으로 위치센서 없는 스위치드 릴럭턴스 전동기의 제어에 관해 연구하였다. 신경회로망은 실험을 통해 구해진 데이터를 바탕으로 회전자 위치추정을 위한 근사함수의 유도를 위해 활용되었으며, 학습된 신경회로망을 이용하여 룩업 테이블을 구성하였다. 제안된 센서리스 알고리즘은 1마력 SRM에 적용되었으며, 실험 및 시뮬레이션을 통해 실현 가능성이 확인되었다.

• 전력전자학회논문지
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• 제17권3호
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• pp.246-251
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• 2012

This paper proposes a new position compensation method for misaligned Hall-effect sensors of BLDCM(Brushless DC Motor). If the Hall-effect sensors are installed at wrong position, the exact rotor position cannot be obtained. Therefore, when the BLDCM is controlled with this wrong position, the torque ripple can be increased and the average torque also decreases. The back-EMF of BLDCM can be obtained by using the voltage equation and by multiplying the back-EMF constant and rotor speed. At a constant speed, the estimated back-EMF by using the multiplication of the back-EMF constant and rotor speed is constant, but the estimated back-EMF from the voltage equation decreases at the commutation point because the line-to-line back-EMF of two conducting phases is start to decrease at this point. Therefore, by using the difference between these two estimated back-EMFs, the commutation point of the phase current can be determined and position compensation can be carried out. The proposed position correction method doesn't require additional hardware circuit and can be easily implemented. The validity of the proposed position compensation method is verified through several experiments.

• 전력전자학회논문지
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• 제17권3호
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• pp.238-245
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• 2012

This paper presents a sensorless speed control of a 2-phase switch reluctance motor(SRM). The proposed sensorless control scheme is based on the slide mode observer with parameter compensator to improve the estimation performance. In the stand still position, the initial rotor position is determined by pulse current responses of each phase windings and the current difference. In order to determine an accurate initial rotor position, the two initial rotor positions are estimated by the difference of the pulse currents. From the stand still to the operating region, a simple open loop control which determines the commutation sequence by the pulse current of the unexcited phase winding is used. When the motor speed is reached to the sensorless control region, the estimated rotor position and speed by the slide mode observer are used to control the SRM. The flux calculator used in the slide mode observer is designed by phase voltage and the voltage drops in the phase resistance of the winding. The accuracy of the flux calculator is dependent on the phase resistance. For the continuous update of the phase resistance, current gradient at the inductance break point is used in this paper. The error of the estimated rotor position at the current gradient position is used to update the phase resistance to improve the sensorless scheme. The proposed sensorless speed control scheme is verified with a practical compressor used in home appliances. And the results show the effectiveness of the proposed control scheme.

• Wind and Structures
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• 제33권6호
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• pp.471-480
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• 2021

This present paper leads to investigation of blade-fluid interactions of cambered blade H-Darrieus rotor having EN0005 airfoil blades using comprehensive Computational Fluid Dynamics (CFD) analysis to understand its performance in low wind streams. For several blade azimuthal angle positions, the effects of three different low wind speeds are studied regarding their influence on the blade-fluid interactions of the EN0005 blade rotor. In the prevailing studies by various researchers, such CFD analysis of H-Darrieus rotors are very less, hence it is needed to improve their steady-state performance in low wind velocities. Such a study is also important to obtain important performance insights of such thin cambered blade rotor in its complete rotational cycle. It has been seen that the vortex generated at the suction side of the EN0005 blade rolls back to its leading edge due to the camber of the blade and thus a peak velocity occurs near to the nose position of this blade at its leading edge, which leads to peak performance of this rotor. Again, in the returning phase of the blade, a secondary recirculating vortex is generated that acts on the pressure side of EN0005 blade rotor that increases the performance of this cambered EN0005 blade rotor in its downstream position as well. Here, the aerodynamic performances have been compared considering Standard k-ε and SST k-ω models to check the better suited turbulence model for the cambered EN0005 blade H-Darrieus rotor in low tip speed ratios.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1992년도 하계학술대회 논문집 B
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• pp.1235-1237
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• 1992

In this paper, a new PWM method and estimating means of rotor position angles for BLDC motor drive are presented. The rotor position angles is predicted by calculated rotor flux from the stator voltage and current signals. The current control PWM using fuzzy logic is also suggested. Performance of the proposed controller is observed through a simulation.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1996년도 창립기념 전력전자학술발표회 논문집
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• pp.21-25
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• 1996

To control the speed of IPMSM drives it is necessary to know the speed and the rotor position. This is normally done by measurement of this values with electromechenical sensors. In this paper, a new approach to the position elimination method for the high performance variable speed IPMSM drives with the current controlled PWM technique is presented. For the high performance drive capability in the speed region, a Extended Kalman filter algorithm is adopted to estimate the rotor position as well as the angular velocity for the practical sensorless IPMSM drives. The high performance drive characteristics of the proposed method are verified using the wide simulation.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2004년도 전력전자학술대회 논문집(2)
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• pp.646-650
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• 2004

This paper presents a novel method to detect the rotor position of the BrushLess DC(BLDC) motor at standstill and a start-up method to accelerate the rotor up to a certain speed where the conventional position sensorless control methods based on the back EMF could work reasonably The proposed initial rotor position estimation method is suitable to avoid the temporary reverse rotation or the starting failure. This method can be implemented using only one current sensor at DC link of the inverter. It does not depend on the model of the motor , and it is robust to motor parameter variations. By the proposed method, it is demonstrated experimentally that a stable starting can be achieved even with severe mechanical disturbance.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 B
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• pp.1191-1193
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• 2001

In switched reluctance motor(SRM) drive, it is necessary to synchronize the stator phase excitation with the rotor position. Therefore, the rotor position information is essential. Usually, optical encoders or resolvers are used to provide the rotor position information. These sensors are expensive and are not suitable for high speed operation. This paper proposes a new encoder for high performance excitation control of SRM. The proposed encoder has complex structures of incremental and absolute encoder. An each phase inductance profile can be synchronized with 4-bit absolute position signal and incremental pulses are used for speed detection. Low cost and simple structure are possible.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 F
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• pp.2761-2763
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• 1999

In this paper, we analyzed the characteristics of the detected EMF signals used to detect the rotor position in the IPM(Interior Permanent Magnet) BLDC motor and SPM (Surface Permanent Magnet) BLDC motor. The position sensing signal, in the IPM BLDC motors, advances the real rotor position due to the variation of the rotor inductances. This fact was verified by the simulation and experiment.