• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1999년도 하계학술대회 논문집 A
• /
• pp.40-42
• /
• 1999

High-speed brushless permanent magnet machines are good for compressor and aerospace applications, etc, since they are conductive to high efficiency, high power density, small size and low weight. This paper describes a diametrically magnetized PM motor with the rating of 4.3kW and 50000 rpm fur high-speed drive applications. To bear strong stress from high speed, rotor was designed cylindrical structure, was magnetized diametrically permanent magnet. The performance characteristic of motor was evaluated by means of FEA(Finite Element Analysis), no-load test And then, in order to find back-EMF constant, used FEA, search coil.

• 조명전기설비학회논문지
• /
• 제21권7호
• /
• pp.109-116
• /
• 2007

다상 브러시리스 교류전동기의 역기전력 파형은 일반적으로 이상적인 정현파나 사다리꼴 형태가 아니다. 그러므로 이상적인 역기전력을 가정하는 기존의 모델로 다상 BLAC 전동기의 특성을 시뮬레이션 또는 해석하는 경우에는 많은 오차가 발생할 수 있다. 본 논문에서는 이러한 오차를 감소시키기 위해 FEA 기반의 회로 및 수식 기반의 혼합 모델링 기법을 이용한 상변수 모델을 제안하였다. FEA로부터 얻어진 역기전력 파형을 포함한 상모델의 파라미터를 사용하는 제안된 혼합 모델링기법은 임의의 역기전력 전압파형을 갖는 다상 브러시리스 교류전동기의 시뮬레이션과 해석에 사용할 수 있다. 제안한 기법을 7상 BLAC 전동기에 적용한 시뮬레이션 및 실험 결과로부터 모델의 타당성을 입증하였다.

• 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.

• Journal of Power Electronics
• /
• 제11권4호
• /
• pp.430-438
• /
• 2011

This article proposes a robust nonlinear control based on Lyapunov's redesign, whose purpose is to deal with parametric uncertainty in the resistance of the motor windings. The robust controller design is based on the passivity properties of the motor, as well as energy shaping and damping injection. The application of this control technique is focused on electric vehicles mainly formed by a battery bank, a power inverter, an AC brushless motor and the mechanical transmission. The sine PWM technique is used to trigger the switching devices of inverter. The results were obtained from simulation, where is shown that robust control makes a proper tracking of electromagnetic torque.

• 전력전자학회논문지
• /
• 제26권2호
• /
• pp.127-134
• /
• 2021

This study presents an overhang-type rail traction system using dual brushless AC (BLAC) motors with hall sensors. For an accurate position and moving length control of the designed rail traction system, instantaneous position controller using speed reference model and modified disturbance observer for BLAC motor with hall sensor are proposed. The presented speed reference model is designed to satisfy the required performance of 200 mm/s with proper acceleration and deceleration slopes to reduce mechanical vibration. Through the instantaneous speed reference model, instantaneous position and speed errors can be compensated together. Furthermore, the modified disturbance observer for BLAC motors with low-resolution hall sensors can improve the torque and speed control performance. The proposed disturbance observer is based on an actual motor speed. However, the feedback speed information of the hall sensor is not enough for use in the low-speed region. The practical adopted disturbance observer uses an activation speed band to the actual torque controller of the designed rail traction system. The proposed position control scheme is verified by the MATLAB-Simulink model and a practical manufactured traction system. In the computer simulation and experiments, the proposed position control scheme shows advanced control performance.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1990년도 추계학술대회 논문집 학회본부
• /
• pp.10-14
• /
• 1990

Variable Structure System(VSS) la being extended to a new control system of ac servo machines for its merits of simple mechanism and robustness. This paper has studied about applying VSS to position control for brushless servo motor. But VSS has the chattering problem of control input. This chattering phenomenon cause acoustic noises, torque ripple and increase harmonics of the current. One of the useful way to eliminate this defect of VSS, linearlizing the switching function is discussed here. Though the conventional method of linearizing the switching function diminishes the chattering, it may degrade the robustness of the system. In this paper, new linearized switching function which shows robust performance to the parametric variation and reduces chattering simultaneously is introduced and assured by simulation.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2001년도 Proceedings ICPE 01 2001 International Conference on Power Electronics
• /
• pp.390-394
• /
• 2001

A dynamic simulation model for the brush less dc (BLDC) motor drives using Matlab is presented. In this model, an entire BLDC motor drive, including power conversion unit, BLDC motor, and speed/torque control system, is investigated. Especially, the PWM inverter is modeled using switching function concept, so that the detailed voltage and current waveforms, such as line-to-line voltages, inverter input current, ac line current, and switch/diode currents, can be obtained and average/rms ratings of the components can be easily calculated. Also, the proposed model is made into modular blocks and it can be easily extended to other ac motor applications with a little modification. The detailed modeling method is explained and its actual implementation is described. The validity of the proposed model is verified by various simulation results.

• 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.

• 전력전자학회논문지
• /
• 제3권3호
• /
• pp.214-221
• /
• 1998

직접 구동용 브러시 없는 직류전동기(BRUSHLESS direct drive motor : BLDD motor)의 강인한 위치제어를 위해 신경망을 사용하여 접근하는 새로운 제어방식이 소개된다. 전향 신경망이 추가된 선형 2차 제어기는 AC서보의 객체지향 방법을 사용함으로서 대략적으로 선형화 되어지는 강인한 BLDD 모터 시스템을 얻기 위해 사용된다. 구동 상태의 온-라인 위상에서 학습되는 이 신경망은 전향신호와 오차 역 전파법(Back-Propagation Method)에 의해 구성된다. 총 노드의 수가 8개이기 때문에 이 시스템은 일반적인 마이크로 프로세서에 의해 쉽게 실현될 수 있다. 일반적인 작동중, 입출력 응답은 표본화되어지고 가중치는 매개변수 또는 부하 토크의 능한 변이를 적용하기 위해 각 표본주기에서 오차 역 전파법에 의해 학습된다. 그리고, 상태공간에서 시스템 분석은 상태 궤환 이득을 얻기 위해 체계적으로 실행했다. 또한, 강인성은 전반적인 시스템응답에 영향력을 주지 않고 얻어진다.

• Journal of Power Electronics
• /
• 제11권2호
• /
• pp.188-193
• /
• 2011

A highly efficient AC-DC converter for small wind power generation systems using a brushless DC generator (BLDCG) is presented in this paper. The market standard AC-DC converter for a BLDCG consists of a three-phase diode rectifier and a boost DC-DC converter, which has an IGBT and a fast recovery diode (FRD). This kind of two-stage solution basically suffers from a large amount of conduction loss and the efficiency greatly decreases under a light load, or at a low current, because of the switching devices with a P-N junction. In order to overcome this low efficiency, especially at a low current, a three-phase bridgcless converter consisting of three upper side FRDs and three lower side Super Junction FETs is presented. In the overall operating speed region, including the cut-in speed, the efficiency of the proposed converter is improved by up to 99%. Such a remarkable result is validated and compared with conventional solutions by calculating the power loss based on I-V curves and the switching loss data of the adopted commercial switches and the current waveforms obtained through PSIM simulations.