2016 Volume 24 Issue 3 Pages 210-215
A square wave excitation is the simplest method of brushless DC motor drive, but it has part inferior in terms of efficiency and vibration noise. However, the efficiency can be clearly improved by extending excitation angle and advancing current phase angle, especially the 150 degree excitation leads maximum efficiency. And the 150 degree excitation has possibility of making vibration noise characteristic improve because it leads losses decrease. In this paper, we measure the motor vibration noise characteristics in 150 degree excitation, and inspect degree of improvement of the characteristics experimentally.