A Novel High Performance Variable Speed PM BLDC Motor Drive System

In this paper, a new module structure of phase locked loop (PLL) speed controller is first proposed for permanent magnet brushless dc (PMBLDC) motor drives to achieve both fast response and high accuracy. The proposed standard module renders the controller design rather simple and straightforward. In addition, in order to reduce the drive cost, a phase current sensing scheme is adopted to properly integrate with the PWM control of the PLL controller. A prototype is also constructed to verify the feasibility of the proposed variable speed drive. It is seen that the proposed drive is rather suitable for practical applications.