Abstract
In the 2-phase excited BLDC motor drives using a unipolar PWM scheme, there exists, in some cases, a unwanted leakage current which flows through the anti -parallel diode in the non-excited phase leg of the inverter. In this paper the cases in which the leakage current exists and the influence of the leakage current are analyzed, and a novel unipolar PWM scheme which can eliminate the leakage current is proposed. The leakage current increases as the motor speed is increased or PWM duty is decreased, and as a result the output power of the motor is reduced considerably. The effectiveness of the proposed unipolar PWM scheme isverified through the comparative simulations and experiments.
본 논문에서는 BLDC MOTOR를 2상 여자 unipolar PWM방식으로 구동할 때 개방된 상의 역병렬 다이오드를 통해 원치 않는 누설전류의 흐름이 생기는 원인 및 영향을 분석하고 이를 제거할 수 있는 개선된 unipolar PWM 방식을 제안하였다. 개방된 상에 흐르는 누설전류는 속도가 증가할수록, PWM duty가 감소할수록 증가하며 전동기 출력의 손실을 초래한다. 제안된 unipolar PWM방식의 유효성을 시뮬레이션 및 실험을 통하여 검증하였다.
