High Dynamic Control a PWM Rectifier under Unbalanced Voltage Supply with Deadbeat Current Controllers

In this paper, a control scheme of a three phase PWM boost rectifier using two parallel current deadbeat controllers is proposed. An unbalanced three-phase system produces the second order oscillation of the main frequency in DC link voltage. Two separated positive and negative sequence synchronous reference frames are applied. By using a notch filter to delete the second order harmonic on each frame, the remaining current components appear as DC parts, which are then processed by the inner control loop. Since the deadbeat digital controller has been proved itself a good solution with fast response, full digitalization, especially for applications based on Microcontroller or DSP, the inner current controllers are here implemented by deadbeat technique instead of conventional PI controllers. Simulation results with Matlab/Simulink/Plecs are also presented to demonstrate the control scheme