DC 전류모델 기반 BLDCM의 센서리스 제어 알고리즘 = (A) new sensorless control of brushless DC motors

다국어 초록 (Multilingual Abstract)

The 3-phase BLDC motor(Brushless DC motor) is widely used for its simple structure and high efficiency. The torque of BLDC motor is calculated multiplying its trapezoidal back EMF by phase currents. Therefore, the torque is ideally uniform if each phase currents are controlled having 120° phase difference and the shape of the back EMF is trapezoidal.
It is required to measure the exact position to drive the BLDC motor, because the maximum torque is generated by synchronizing the phase current with the flux linkage which is represented by the permanent magnet rotor. Generally, hall effect sensors, encoders and resolvers are used for the position sensor. However, there are some significant disadvantage using these sensors in the aspects of the drive cost, the volume needs, the noise immunity and the performance reliability. Therefore, It has been investigated in several studies to driving BLDC motors without the position sensors. The conventional sensorless methods are following.
It is the most widely used sensorless method detecting the ZCP(Zero Crossing Point) of the back EMF. However, estimating the exact CP(Commutation Point) with this algorithm requires phase delay filters and additional circuits. Moreover, the estimation performance decreases in the low and high speed region.
Another position estimation method detecting 3rd harmonics of the back EMF requires the neutral point of the BLDC motor, which is not available in common, and additional circuits are also needed.
The ZCP of the back EMF is also detected by measuring the freewheeling current of the open phase, but it is very hard to measure the freewheeling current in the low speed region and additional circuits are also needed.
In this paper, a new sensorless method for BLDC motors is proposed with estimating back EMF using Idc and Idc_Model error. And then estimating angle and speed using back EMF. there is no additional circuits and it is robust to parameter errors. The simulations and experimental results are shown to verify the proposed method.

목차 (Table of Contents)

• 제 1 장 서 론 1
• 제 2 장 BLDC 전동기의 센서리스 제어 연구 동향 4
• 2.1 3상 BLDC 전동기의 수학적 모델링 4
• 2.2 3상 BLDC 전동기 제어 6
• 2.3 센서리스 제어를 위한 기존의 방법 8
• 2.3.1 비도통 상의 단자전압을 이용한 ZCP 검출 8
• 2.3.2 역기전력의 제 3 고조파 검출 10
• 2.3.3 비도통 상의 환류 전류 검출 14
• 2.3.4 역기전력 상수를 이용한 전환 시점 판별 17
• 제 3 장 전류모델기반 센서리스 제어 알고리즘 분석 23
• 3.1 동기좌표변환 개념을 이용한 BLDC 전동기의 d-q축 전류 23
• 3.2 동기좌표변환 개념을 이용한 BLDC 전동기의 역기전력, 속도 및 각 추정 28
• 제 4 장 제안한 센서리스 제어 알고리즘 33
• 4.1 제안한 전류모델 기반 센서리스 제어 알고리즘 33
• 4.2 파라미터 오차의 영향 및 보상 방법 39
• 4.2.1 직류기 모델의 오차 39
• 4.2.2 고정자 저항 오차의 영향 40
• 4.2.3 파라미터 오차의 보정 방법 41
• 제 5 장 디지털 시뮬레이션 47
• 5.1 시뮬레이션 구성 47
• 5.2 시뮬레이션 결과 50
• 제 6 장 실험 결과 및 검토 56
• 6.1 시스템 구성 56
• 6.2 실험 결과 59
• 제 7 장 결 론 66
• 참고 문헌 67
• 부록 A 70
• Abstract 71