• 전력전자학회:학술대회논문집
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• 전력전자학회 2002년도 전력전자학술대회 논문집
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• pp.129-132
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• 2002

The first purpose of this paper is to develop the sensorless drive at adjustable speed without any mechanical position or speed sensor. For this, this research analyzes terminal voltage, finds the rotor position information and makes the source of commutations of phase current. The second purpose is to propose the sensing method of initial rotor position without instantaneous rotating. Experimental results show the validity and practical use of the proposed sensing method.

• Journal of Power Electronics
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• 제12권2호
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• pp.294-304
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• 2012

This paper proposes a fuzzy speed tracking controller and a fuzzy rotor angular acceleration observer for a surface-mounted permanent magnet synchronous motor (SPMSM) based on the Takagi-Sugeno (T-S) fuzzy model. The proposed observer-based controller is robust to load torque variations since it utilizes rotor angular acceleration information instead of the load torque value. Linear matrix inequality (LMI) sufficient conditions are given to compute the gain matrices of the speed tracking controller and the observer. In addition, it is mathematically verified that the proposed observer-based control system is asymptotically stable. Simulation and experimental results are presented to confirm that the proposed control algorithm assures a better transient behavior and less sensitivity under model parameter variations than the conventional PI control method.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제55권2호
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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.

• 한국유체기계학회 논문집
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• 제17권4호
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• pp.70-75
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• 2014

In this paper a analysis method is presented to obtain the steady state dynamic response from the finite element based equations of a rotor-bearing system with initial deflection. The method has been applied to analyze the dynamic response of the two-shaft rotor-bearing system with rigid coupling offset in a heavy duty gas turbine-generator. Bumps in the dynamic response of each rotor system have been observed at each critical speed due to the effect of initial deflection for rigid coupling offset. And, the dynamic responses have been shown to reduce for operating condition changes from cold to hot.

• 전기학회논문지
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• 제60권1호
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• pp.50-62
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• 2011

In this paper, analytical techniques for performance characteristics analysis of wind power generator with outer permanent magnet rotor are proposed. Furthermore, the proposed analytical techniques are validated by performance experiments of the manufactured generator. In this part, characteristic equations of losses such as copper loss, core loss are derived. Using the derived loss characteristic equations, electrical parameters obtained in [15] and d-q axes method, constant load and constant speed characteristics of wind power generator are analyzed. And then, to analyze performance of wind power system according to wind speed, d-q analysis model considering wind turbine characteristics is proposed. Finally, the obtained performance characteristics results are validated in comparison with those by experiments.

• 전기학회논문지P
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• 제63권4호
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• pp.241-247
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• 2014

This paper propose a variable parameter estimations of five-phase squirrel-cage induction motor(IM) for speed control system. In order to high performance control of AC motor using a field oriented control(FOC) and direct torque control(DTC) algorithm, there are required precise motor parameters for slip calculation, flux observer, controller gain, rotor position, speed estimation, and so on. We are suggest a analyzed estimation results of the motor parameters that developing five-phase squirrel-cage IM have a stator of concentrated winding for experimental of variable input power frequency. There are results of stator winding test, no-load test, locked-rotor test, variable actual load test, and estimated parameters of equivalent circuits using manufactured experimental apparatus by IEEE Standard Test Procedure for Polyphase Induction Motors and Generators 112-2004.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 A
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• pp.173-175
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• 1999

This paper deals with the rotor vibration analysis of Switched Reluctance Motor(SRM) with the 6/4 poles. For this analysis, 3-dimensional mode shapes corresponding to the natural frequency and critical speed map according to rotor speed are presented by using 3D Transfer Matrix Method(TMM). The gyroscopic effect and shear deformation of rotor are considered.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2004년도 춘계학술발표대회 논문집
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• pp.91-94
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• 2004

A cyclocopter with the cycloidal blades system can be the type of UAV which can combine the high-speed characteristics of the conventional airplane with the low-speed characteristics of the helicopter. The cycloidal blades system, which can be described as a horizontal rotary wing, offers powerful thrust levels, and a unique ability to change the direction of the thrust almost instantly. Rotor blades are designed to withstand tremendous transverse centrifugal loadings, and responding to a number of aerodynamic harmonic vibratory forcing frequencies. To reduce the weight and increase the strength, the blades are made of composite materials. The blades consist of the skin, spar, and trailing stiffener. In this study, static and dynamic behaviors of cyclocopter rotor blades are analyzed by using MSC/NASTRAN.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2002년도 추계학술대회 논문집
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• pp.411-416
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• 2002

In a high speed spindle system, it is very important to monitor the state of rotating rotor. Particularly in active control spindle system, the position sensor must provide feedback to the control system on the exact position of the rotor. In order to monitor the state of a high speed spindle exactly, high accuracy and wide frequency bandwidth of sensors are important. The focus in this paper is to make a fiber optic sensor for monitoring rotor of magnetic bearing, to design the circuit for detecting optical signal, and to evaluation static and dynamic characteristics of fiber optic sensor.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2001년도 전력전자학술대회 논문집
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• pp.231-234
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• 2001

The torque of SRM depends on phase current and the derivative of inductance. But the inductance of SRM is nonlinearly changed according to rotor position angle and phase current because of saturation in magnetic circuit. Therefore this has a concern in torque ripple and speed variation, and it is difficult to control the desired torque The torque of SRM depends on phase current and the derivative of inductance. But the inductance of SRM is nonlinearly changed according to rotor position angle and phase current because of saturation in magnetic circuit, and it is difficult to control the desired torque. This paper proposes an optimization control scheme by adjusting both the turn-on and turn-off angle according to high efficiency points which are simulated by GA-Neural Network, which is used to simulate the reasonable switching angle which is nonlinearly varied with rotor speed and load.