International Research Publication House
In this paper, the authors propose a new position senseless drive for BrushLess DC (BLDC) motors. Typical senseless control methods such as the scheme with the back-EMF detection method show high performance only at a high speed range because the magnitude of the back-EMF is dependent upon the rotor speed. This paper presents different senseless control method. In the proposed method, a trapezoidal back-EMF is modeled as an unknown input and the proposed unknown input observer estimating a line-to-line back-EMF in real time makes it possible to detect the rotor position.