• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2008년도 제39회 하계학술대회
• /
• pp.721-722
• /
• 2008

This paper deals with comparison and analysis for rotor losses of permanent magnet synchronous generator using phase current harmonic analysis according to dc and ac load. On the basis of analytical field analysis, the rotor losses are analysed. Particularly, rated speed and ac load and the rated speed and dc load conditions are considered. This paper compared rotor losses considered dc load with rotor losses considered ac load. Although our analytical modes is low speed, the rotor losses must be considered by results.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
• /
• 제3B권1호
• /
• pp.59-64
• /
• 2003

This paper presents a new rotor position estimation method for brushless DC motors. The estimation error of the rotor position clearly provokes the phase shift angle misaligned between the phase current and the back-EMF waveforms, which causes torque ripple in brushless DC motor drives. Such an estimation error can be reduced with the help of the proposed neutral-voltage-based estimation method, which is structured as a closed loop observer. A neutral voltage appearing during the normal mode of the inverter operation is found to be an observable and control table measure, which can be used for estimating an exact rotor position. This neutral voltage is obtained from the DC-link current, the switching logic, and the motor speed values. The proposed algorithm, which can be easily implemented by using a single DC-link current and the motor terminal voltage sensors, is verified by simulation and experiment results.

• 전기학회논문지P
• /
• 제56권3호
• /
• pp.129-135
• /
• 2007

This paper deals with speed-sensorless control of DC servo motor using Neuro-Fuzzy Observer. DC servo motor has very low rotor inertia and excellent response characteristic and it is very useful to control torque and speed. It is easy to detect the voltage and current and resolver or encoder is used to measure a rotor speed. But it has a limit as a driving speed to detect speed precisely. So it is problem to improve the performance of the driving system. To solve this problem, it is studied to detect a speed of DC servo motor without sensor. In particular, study on the method to estimate the speed using the observer is performed a lot. In this paper, the gain of the observer is properly set up using the Neuro-Fuzzy control and Neuro-Fuzzy Observer that have a superior transient characteristic and is easy to implement compared the existing method is designed. It calculates the differentiation of the rotor current directly using the rotor current measured in the DC servo motor and estimates the speed of the rotor using the differentiation. Proposed speed sensorless control method is performed using the estimated speed. Also, it is proved feasibility of the proposed observer from the comparison tested a case with a speed sensor and a case without a speed sensor which used a highly efficient drive and 200[w] DC servo motor starting system.

• Journal of Power Electronics
• /
• 제5권1호
• /
• pp.62-66
• /
• 2005

A simple fault correction method for rotor position detection of a brushless DC(BLDC) motor with trapezoidal back EMF(electromotive force) using a Hall effect latch unit is presented. The reason why the Hall effect latch unit does not operate properly during the startup of a BLDC motor is thoroughly explained. To solve this problem, a simple code change method and its hardware implementation issues are proposed and discussed.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2019년도 전력전자학술대회
• /
• pp.374-375
• /
• 2019

In this paper, In the whole industry, there is a tendency to replace brushless motors with brushless motors because of the high rate of failure in DC motors with brushes. Accordingly, many methods for driving a brushless motor have been developed and studied. In order to drive the brushless motor, it is essential to know the information about the rotor position of the motor. However, it is not possible to use a position sensor for rotor disconnection due to the structure of an electric compressor brushless DC motor. In this paper, we investigate the rotor position of the motor by using the counter electromotive force included in the voltage of the terminal made by Y connection by using the resistance of each phase without using Hall sensor or encoder generally used to detect the rotor position. A sensorless drive system for a square wave brushless direct current (DC) motor is proposed. To do this, we propose a method to detect the rotor position from the analyzed terminal voltage waveform by performing terminal voltage analysis of each phase for 3-phase, 2-exciton unipolar PWM.

• 전력전자학회논문지
• /
• 제21권5호
• /
• pp.449-452
• /
• 2016

This paper presents a simplified analysis on the rotor position detection error in sensorless interior permanent magnet brushless DC motor (BLDCM) drives, wherein terminal voltage sensing based on the back-electromotive force (back-EMF) zero-crossing point detecting circuitry is employed. The effect of a rotor saliency on the back-EMF's zero-crossing point detection is analyzed using the extended EMF-based voltage equation of the interior permanent BLDCM in a stationary reference frame, and thus the overall analysis is considerably simplified compared to the conventional one. Simulation results are provided to verify the effectiveness of the proposed method.

• Journal of Power Electronics
• /
• 제14권3호
• /
• pp.564-571
• /
• 2014

Rotor initial position is an important factor affecting the control performance of electrically excited synchronous motors. This study presents a novel method for estimating rotor initial position based on sliding discrete Fourier transform (sDFT). By injecting an ac excitation into the rotor winding, an induced voltage is generated in stator windings. Through this voltage, the stator flux can be obtained using a pure integral voltage model. Considering the influence from a dc bias and an integral initial value, we adopt the sDFT to extract the fundamental flux component. A quadrant identification model is designed to realize the accurate estimation of the rotor initial position. The sDFT and high-pass filter, DFT, are compared in detail, and the contrast between dc excitation and ac injection is determined. Simulation and experimental results verify that this type of novel method can eliminate the influence of dc bias and other adverse factors, as well as provide a basis for the control of motor drives.

• 전력전자학회논문지
• /
• 제9권5호
• /
• pp.491-497
• /
• 2004

본 논문은 브러시리스직류전동기의 새로운 회전자위치추정 방법에 관한 것이다. 회전자 위치추정이 부정확하게 이루어졌을 때, 역기전력과 상전류 사이의 위상차가 나타나고 이는 다시 전동기의 토크리플을 일으킨다는 사실은 알려져 있다. 이러한 추정오차를 줄이기 위하여 인버터의 정상모드 기간 중에 나타나는 중성점전압을 기반으로 하는 새로운 방법을 제안하고 있다. 이 중성점전압이 효과적인 회전자 위치 추정오차의 한 지표임을 확인하고, 중성점전압의 발생, 획득방법, 보상방법 등을 다루고 있다. 본 알고리즘은 전동기 단자전압센서와 단일 직류링크 전류센서 만을 이용하여 실현할 수 있으며, 관련 시뮬레이션 및 실험결과는 그 타당성을 보여주고 있다.

• 반도체디스플레이기술학회지
• /
• 제23권1호
• /
• pp.48-51
• /
• 2024

Recently, high-performance BLDC(Brushless DC) motors are being applied to various fields such as industrial and personal mobility devices and drones. To achieve the best performance of BLDC, sensors such as hall sensors, encoders, and resolvers are used to determine the position of the rotor, and various speed control technologies are being developed. However, due to problems with high-speed control due to external environmental factors and frequency bandwidth of semiconductor sensing devices, research on BLDC motors without semiconductor sensing devices is in progress. Therefore, in this study, a signal brush was added to the end of the rotor of a BLDC motor and the rotor position of the BLDC motor was detected by analyzing the signal output through the signal brush.

• 전력전자학회논문지
• /
• 제5권1호
• /
• pp.95-103
• /
• 2000

본 논문에서는 브러시리스 직류 전동기용 센서리스 드라이브의 성능 향상을 위한 새로운 회전자 위치 간접 검출 방식을 제안한다. 단자 전압을 이용하는 기존의 회전자 위치 간접 검출 방식들은 전동기를 동기 모드로 운전시 과도한 전압이 인가되면 회전자 위치를 정확히 검출할 수 없기 때문에 센서리스 운전 모드로의 신속한 전환이 어렵다. 따라서 본 논문에서는 전동기를 동기 모드로 운전하는 경우, 과전압에 의한 단자 전압과 역기전력 파형의 관계를 분석하여 저속 운전 영역에서도 회전자 위치를 정확히 검출할 수 있는 새로운 간접 검출 방식을 제안한다. 또한 실험을 통하여 제안한 방식의 효용성을 입증한다.