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

• 항공우주시스템공학회지
• /
• 제2권4호
• /
• pp.19-24
• /
• 2008

In this study gives detail on the composition and process of Quad-rotor blade Vehicle. It may seem simple but we have many trouble because of many subtleties. Unless designed carefully, it is very difficult to control of stability by reason of disturbances in the air and unbalance in the motor. We want to have a more stable output so add other electronics supplement, and change the battery in oder to increasing thrust. It cannot be done quickly, nor cheaply because it is more difficult than first ideas that control of Quad-rotor. But we complete manufacture of basically controllable vertical takeoff and landing aircraft.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
• /
• 제51권7호
• /
• pp.331-338
• /
• 2002

An inverter-fed induction is driven by a harmonic voltage source so that it is necessary to be analysed by time-stepping F.E.M. But it takes so long time that disadvantageous to design. This paper presents a simple analysis method for inverter-fed induction motor using FEM and harmonic equivalent circuit. First, the rotor bar resistance and the leakage reactance are determinated by FEA for 1 slot region in rotor to consider the skin effect and the saturation. Secondly, the characteristic of the motor is analyzed by the harmonic equivalent circuits consisting of the obtained parameters from the FEA. This method is carried out to analyze an induction motor driven by the sinusoidal voltage and the inverter. The results are verified by comparing with those of the time-step F.E.A and the experiment.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2001년도 추계학술대회논문집A
• /
• pp.533-538
• /
• 2001

This paper describes a combinational method to compute the global and local solutions of optimization problems. The present hybrid algorithm uses both a genetic algorithm and a local concentrate search algorithm (e. g simplex method). The hybrid algorithm is not only faster than the standard genetic algorithm but also supplies a more accurate solution. In addition, this algorithm can find the global and local optimum solutions. The present algorithm can be supplied to minimize the resonance response (Q factor) and to yield the critical speeds as far from the operating speed as possible. These factors play very important roles in designing a rotor-bearing system under the dynamic behavior constraint. In the present work, the shaft diameter, the bearing length, and clearance are used as the design variables.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2008년도 춘계학술대회논문집
• /
• pp.735-741
• /
• 2008

Identification of asymmetry and anisotropy of rotor system is important for diagnosis of rotating machinery. Directional frequency response functions (dFRFs) are known to be a powerful tool in effectively detecting the presence of asymmetry or anisotropy. In this paper, an input noise effect of dFRFs for rotors is estimated, when both asymmetry and anisotropy are present. The normalized random errors of the dFRFs are calculated to verify the validity of the method, which is demonstrated by numerical simulation with a simple rotor model.

• The Journal of the Acoustical Society of Korea
• /
• 제16권1E호
• /
• pp.29-34
• /
• 1997

Numerical prediction of aerodynamic noise radiated by subsonic rotors are carried out. A computer program has been developed which incorporates both the discrete frequency noise as well as the broadband noise arising from the ingestion of turbulence. Acoustic analogy is used in conjunction with Homicz's formulation of turbulence ingestion noise. Formulation 1A of Farassat is used to enhance the numerical analysis performance of Ffowcs-Williams Hawkings equation by eliminating the numericla time differentiation. Homicz's trubulence ingestion noise prediction technique is used to understand the characteristics of broadband noise radiated by isotropic trubulence in gestion. Numerical predictions are carried out for a number of rotor configurations and compared with experimental data. Monopole consideration of transonic rotor agrees well with both the experimental data and the linear theory. Noise radiation characteristics of rotor at lifting hover are investigated utilizing simple blade loading obtained by thin wing section theory. By incorporating discrete noise prediction of steady loading with broadband spectrum, much better agreement with experimental data is obtained in the low frequency region. The contributions from different noise mechanisms can also be analyzed through this method.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 1998년도 Proceedings ICPE 98 1998 International Conference on Power Electronics
• /
• pp.137-142
• /
• 1998

This paper describes a simple vector control scheme for the wound rotor type induction motors(WRIM) without the additional speed sensor in order to remove the external resistor bank which is usually adapted for the WRIM speed control. The motor angular speed is obtained indirectly from the slip angular speed is obtained indirectly from the slip angular speed and the slip angular speed is estimated by detecting the rotor currents only. Because the motor parameters are not included in the estimation algorithm, the proposed algorithm is free from the variation of the motor parameters and the robust sensorless vector control can be achieved. The performance of the proposed scheme is verified through the digital simulation.

• 전력전자학회논문지
• /
• 제8권5호
• /
• pp.427-434
• /
• 2003

본 논문은 스위치드 릴럭턴스 전동기(SRM)에서 회전자위치검출의 새로운 방법을 다루었다. 전동기에 대한 센서리스방식의 제어기법들은 상전류의 측정과 비여자 구간에서의 펄스전압인가를 포함하고 있다. 회전자의 위치를 추정 할 수 있는 윈리는 펄스 전류를 통한 인턱턴스의 검출을 기포로 한다. 이 센서리스 제어법은 회전자의 위치검출 연산이 매우 간단하여 전속도구간에서 운전이 가능하여 드라이브 시스템을 효율적으로 구성할 수 있다. 제안한 방식을 이용하여 구동시스템을 구성하고 실험을 통하여 검증하였다.

• 전자공학회논문지B
• /
• 제33B권7호
• /
• pp.183-188
• /
• 1996

In this paper, we propose a new method which estimates the initial position of a PM synchronous motor (PMSM) using an incremental ecoder. in cremental encoders are widely used in detecting rotor position since they are inexpensive. At starting procedure, however, the incremental encoders cannot give the information of the absolute rotor position. Hence, additional absolue encoder, which has $60^{\circ}C$ resolutio electrically, and signal lines called U, V, W, have been used in practical systems for starting injection of a high frequency test current. It does not require any additional information such as U, V, W signals for starting procedure and allows for cheap and simple implementation. Experimental results show that the proposed method can estimate the initial rotor positon with higher accuracy than the conventional method using U, V, W signals.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2005년도 전력전자학술대회 논문집
• /
• pp.417-420
• /
• 2005

In this paper proposes a very simple method to estimate the rotor position of a switched reluctance motor. By on-line estimating the self-inductance of the motor, the rotor position of the SR motor is obtained, and a closed-loop drive system can be achieved. Proposed methods can easy implement to application with sensorless SR motor drive system. Speed 2000rpm SR motor simulation executed with self inductance estimation and result represented. Simulation result verified the rotor position using the proposed self-inductance estimation method.