A novel voltage sensorless DPC approach of AFE rectifier based on virtual flux and dynamic DC link reference design

In this work, a novel voltage sensorless Direct Power Control (DPC) approach of Active Front End (AFE) rectifier based on virtual flux and dc-link dynamic reference design technique is presented. Firstly, the PI controller is eliminated from the outer dc-link voltage control loop with the application of dynamic dc-link reference design technique and line voltage sensors by using virtual flux technique. Further, a simple way to obtain the dc-link voltage based on the switching states of the rectifier is implemented to remove the outer loop voltage sensor also and hence the voltage sensorless DPC approach has achieved. Finally, the Experimental results of both the approaches, one with dc-link voltage sensor but without PI controller and another with the absence of both PI controller and dc-link voltage sensor is presented. Numerical experimental results depict the better control from the proposed techniques regarding reduction in active, reactive power ripple and THD in the line current.