Semi-Vector Controlled PM Synchronous Motor Drive

Vector control and self-control are the most widely used control techniques of the PM synchronous motor. Self-control technique is comparatively simple and cost-effective compared to vector control. However, this technique is unable to provide satisfactory performance for sinusoidal back E.M.F. machines. Self-control is suitable for trapezoidal back EMF motors. The vector control technique is the best high-performance control technique of sinusoidal back E.M.F. machines. In this paper, a semi-vector control scheme is discussed for sinusoidal back E.M.F. machines. The major advantage of this scheme over vector control is that reference frame transformations of motor variables and close current control are not required which makes the drive simple and less costly than vector control drive. The performance of the semi-vector control drive is in between vector control and self-control drives. The developed drive can be used for many industrial and domestic applications in place of a self-control drive. Performance of the drive is being validated by experimental study and satisfactory results are found.