• 전기학회논문지P
• /
• 제53권3호
• /
• pp.103-109
• /
• 2004

This paper has presented, taking an example of a gas separation plant, dynamic analysis on frequency decline caused by the over-loading at the generator and the knee point causing voltage instability due to reactive power required by re-acceleration of large induction motors, resulting in phenomena of failure in the conventional frequency load shedding. In order to resolve the voltage instability problem, a design of load shedding system employing under-voltage relays has been proposed to the industrial power system containing large induction motors in addition to the conventional load shedding employing frequency relays. For the purpose of dynamic analysis, models of gas turbine and governor, synchronous generator, brushless exciter, and induction motor are introduced.

• 전기학회논문지
• /
• 제58권11호
• /
• pp.2162-2167
• /
• 2009

A Low cost and variable speed brushless motor drive system with single switch per phase is presented. The motor drive is realized with a novel two-phase flux-reversal-free switched reluctance motor and a split AC two switch converter. The strategy of the controller and the converter for its realization are described. Comparisons between a split AC converter, asymmetric converter, split DC converter, single controllable switch converter, and N+1 converter are performed for its device rating, cost, switching losses and conduction losses, and converter efficiency. The split AC converter is analyzed and simulated to verify the characteristics of the converter circuitry and control feasibility and the simulation results are presented. The efficiency with various loads is numerically estimated and experimentally compared from viewpoint of subsystem and system in details. The focus of this paper is to compare the presented motor drive system to the asymmetric converter system throughout experiments and demonstrate single switch per phase converter having comparable efficiency as the asymmetric converter system.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2007년도 제38회 하계학술대회
• /
• pp.890-891
• /
• 2007

This paper deals with design and characteristic analysis of Brushless DC (BLDC) motor using fuel-pump. First, we derived design factor from simplified design characteristic equation. Second, we decided design parameter from design factor using finite element analysis (FEA). Finally, analyze characteristics for BLDC using FEA according to load condition.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2001년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
• /
• pp.57-60
• /
• 2001

This paper presents a new method for removing reaching phase in variable structure control systems using Bell type switching function. By proposed method, during the entire control process reaching phase is removed. For effective speed control of trapezoidal type brushless DC motor, a time varying switching function based speed controller is developed as illustration.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2005년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
• /
• pp.80-82
• /
• 2005

This paper presents the dynamic characteristics of a linear brushless DC(BLDC) motor with permanent magnet excitation for the precision conveyor according to the load condition. In order to investigate the accurate dynamic performance of tile linear BLDC motor driving with 6 step inverter- fed, finite element techniques coupling with external circuit models, together with the simultaneous simulation of motion of the mover system, arc proposed. The results of finite element analysis arc compared to the experimental ones.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2005년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
• /
• pp.83-85
• /
• 2005

대용량 추진용 32극, 96슬롯의 5MW급의 BLDC(Brushless DC) 전동기를 설계하고, 그 특성을 유한요소해석법(FEM)을 이용하여 해석하였다. 해석 결과를 이용하여 진동 및 소음의 원인이 되는 가진력(Magnetic Exciting Force)을 계산할 수 있는 알고리즘을 제안한다. 계산된 가진력을 분석하여 진동 및 소음의 원인을 줄일 수 있는 방안을 모색하고, 이를 설계에 반영함에 그 목적이 있다. 이러한 과정을 통하여 BLDC전동기 설계에 이 기술을 적용하여 전동기의 소음 및 진동의 저감과 성능을 향상시킬 수 있는 방법을 제시한다.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2005년도 제36회 하계학술대회 논문집 B
• /
• pp.963-965
• /
• 2005

본 연구는 대용량 추진용 32극, 192슬롯의 3MW급의 BLDC(Brushless DC) 전동기를 모델로 2차인 유한요소법(FEM)을 이용 전자계 및 열계 특성을 해석한 것이다. 이러한 해석을 통하여 BLDC 전통기의 진동 및 소음의 원인을 분석하고 성능향상을 위한 방법을 연구하며 이에 전동기의 소음 및 진동의 저감과 성능을 향상시킬 수 있는 최적설계에 그 목적이 있다. 또한 FEM을 이용 열계 특성을 해석하고 이를 분석하여 설계정수 변경에 반영한다. 위의 결과들을 설계에 적용하여 BLDC의 성능향상을 위한 최적설계 모델을 제시하게 될 것이다.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2005년도 제36회 하계학술대회 논문집 B
• /
• pp.1071-1073
• /
• 2005

This paper investigates magnetic field behavior and its iron losses in the stator core using electrical steels. The analysis model is a brushless motor with the permanent magnet. The elliptical rotating and alternating flux distributions with non-sinusoidal waveforms are obtained by Finite Element Method and then their harmonic components are extracted. Based on these results, the local iron losses in the stator core caused by the harmonic flux are calculated. Furthmore, this paper explains the relation between the complex flux waveform and iron loss produced in each part of the stator core.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1998년도 추계학술대회 논문집 학회본부A
• /
• pp.43-45
• /
• 1998

ADD has developed a special BLDCM(brushless d.c. motor) that has small size and high power density. The model of BLDCM is like that of advanced nation. Design, production and test carried out with ADD and HICO. Now the performance of BLDCM is achieved 65% of design data. Also we are concerned with adhesion of magnet in rotor for high speed.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1995년도 하계학술대회 논문집 A
• /
• pp.294-296
• /
• 1995

In this paper, a vector control method for a AC-Excited BLSM(Brushless Synchronous Motor) is proposed. The BLSM has a feature that separate exciter is not needed for excitation. The proposed method is described in two parts as follow, one is the design of drive and the other is a modeling for its implementation. Rotor flux is estimated using indirect sensing method based on voltage equation in the synchronously rotation reference frame. And rotor position is calculated from rotor angular velocity and stator current. Through computer simulation results of this proposed system, it is shown that the BLSM drive has a ability of precision torque control from the static and dynamic performance.